Notes: hydrazine and titanium ============================================================ FN ISI Export Format VR 1.0 PT J AU Linnik, O Kisch, H AF Linnik, Oksana Kisch, Horst TI On the mechanism of nitrogen photofixation at nanostructured iron titanate films SO PHOTOCHEMICAL & PHOTOBIOLOGICAL SCIENCES LA English DT Article ID FLUIDIZED-BED REACTOR; PHOTOCATALYTIC REDUCTION; TITANIUM-DIOXIDE; DINITROGEN PHOTOREDUCTION; NITRATE IONS; AMMONIA; OXIDATION; CATALYSTS; WATER; TIO2 AB The photofixation of dinitrogen to ammonia at a nanostructured iron titanate thin film, prepared from iron(III) chloride and titanium tetraisopropylate, was established by isotopic labeling employing N-15,15(2). It is found that traces of iron chloride in the film are required to observe significant amounts of ammonia. It is therefore proposed that the photogenerated hole oxidizes chloride to an adsorbed chlorine atom and the latter subsequently oxidizes ethanol, the reducing agent necessary for ammonia formation. However, thin films obtained from a chloride-free precursor like iron tris-acetylacetonate are also active. Upon prolonged irradiation ammonia is oxidized to nitrate by traces of oxygen. It is found that this final reaction step does not require photoexcitation of the iron titanate thin film but occurs thermally. Titania films exhibit about the same catalytic activity in ammonia oxidation whereas iron oxide films are much less active. Contrary to this thermal reaction step, the reduction of intermediate hydrazine by ethanol occurs only photochemically. C1 Univ Erlangen Nurnberg, Inst Anorgan Chem, D-91058 Erlangen, Germany. RP Kisch, H, Univ Erlangen Nurnberg, Inst Anorgan Chem, Egerlandstr 1, D-91058 Erlangen, Germany. NR 30 TC 0 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 1474-905X J9 PHOTOCHEM PHOTOBIOL SCI JI Photochem. Photobiol. Sci. PY 2006 VL 5 IS 10 BP 938 EP 942 PG 5 SC Biochemistry & Molecular Biology; Biophysics; Chemistry, Physical GA 091AZ UT ISI:000240999400010 ER PT J AU Rane, KS Mhalsiker, R Yin, S Sato, T Cho, K Dunbar, E Biswas, P AF Rane, K. S. Mhalsiker, R. Yin, S. Sato, T. Cho, Kuk Dunbar, E. Biswas, Pratim TI Visible light-sensitive yellow TiO2-xNx and Fe-N co-doped Ti1-yFeyO2-xNx anatase photocatalysts SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article DE hydrazine; oxalate precursor; oxalate-hydrazinate precursor; anatase; arrhenius plots; electrical conductivity; N-TiO2; XPS-N 1s peak; photodegadation; ESR; Fe-N co-doped TiO2 ID OXALATO HYDRAZINATE PRECURSORS; ELECTRICAL-CONDUCTIVITY; PHOTOELECTROCHEMICAL PROPERTIES; TITANIUM-DIOXIDE; FERRITE; OXIDES; IRON; DECOMPOSITION; GAMMA-FE2O3; RESONANCE AB Nitrogen substituted yellow colored anatase TiO2-xNx and Fe-N co-doped Ti(1-y)FeyO(2-x)N(x) have been easily synthesized by novel hydrazine method. White anatase TiO2-delta and N/Fe-N-doped samples are semiconducting and the presence of ESR signals at g similar to 1.994-2.0025 supports the oxygen vacancy and g similar to 4.3 indicates Fe3+ in the lattice. TiO2-xNx has higher conductivity than TiO2-x and Fe/Fe-N-doped anatase and the UV absorption edge of white TiO2-x extends in the visible region in N, Fe and Fe-N co-doped TiO2, which show, respectively, two band gaps at similar to 3.25/2.63, similar to 3.31/2.44 and 2.8/2.44eV. An activation energy of similar to 1.8eV is observed in Arrhenius log resistivity vs. I IT plots for all samples. All TiO2 and Fe-doped TiO2 show low 2-propanol photodegradation activity but have significant NO photodestruction capability, both in UV and visible regions, while standard Degussa P-25 is incapable in destroying NO in the visible region The mid-gap levels that these N and Fe-N-doped TiO2 consist may cause this discrepancy in their photocatalytic activities. (c) 2006 Elsevier Inc. All rights reserved. C1 Goa Univ, Dept Chem, Panaji 403206, Goa, India. Tohoku Univ, Inst Multidisciplinary Res Adv Mat, Aoba Ku, Sendai, Miyagi 9808577, Japan. Washington Univ, Sch Engn & Appl Sci, St Louis, MO 63130 USA. RP Rane, KS, Goa Univ, Dept Chem, Panaji 403206, Goa, India. EM ksrane@unigoa.ac.in NR 47 TC 0 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD OCT PY 2006 VL 179 IS 10 BP 3033 EP 3044 PG 12 SC Chemistry, Inorganic & Nuclear; Chemistry, Physical GA 085XQ UT ISI:000240638100009 ER PT J AU Baunemann, A Kim, Y Winter, M Fischer, RA TI Mixed hydrazido amido/imido complexes of tantalum, hafnium and zirconium: potential precursors for metal nitride MOCVD SO DALTON TRANSACTIONS LA English DT Article ID CHEMICAL-VAPOR-DEPOSITION; SINGLE-SOURCE PRECURSORS; THIN-FILMS; ORGANOIMIDO COMPLEXES; GATE-ELECTRODE; NIOBIUM; TITANIUM; BEHAVIOR; VANADIUM; CRYSTAL AB The coordination chemistry of the hydrazine derivatives dimethylhydrazine (Hdmh) and N-trimethylsilyl-N'N'-dimethylhydrazine (Htdmh) at Ta, Zr and Hf was investigated aiming at volatile mixed ligand all-nitrogen coordinated compounds. The hydrazido ligands were introduced either by salt metathesis employing the Li salts of the hydrazines and the tetrachlorides MCl4 (M = Zr, Hf) or by amine substitution using M(NR2)(4) (R = Me, Et) and [(t-BuN)Ta(NR2)(3)]. The new complexes were fully characterised including H-1/C-13 NMR, mass spectrometry and a study of their thermal behaviour. The crystal structures of [ZrCl(tdmh)(3)] and the all-nitrogen coordinated complex [Ta(N-t-Bu)(NMe2)(2)-(tdmh)] are discussed as well as the structure of the by-product [Li(tdmh)(py)](2). Preliminary MOCVD experiments of the liquid compound [Ta(NEt2)(2)(N-t-Bu)(tdmh)] were performed and the deposited TaN(Si) films were analysed by RBS and SEM. C1 Ruhr Univ Bochum, Lehrstuhl Anorgan Chem Organomet & Mat Chem 2, D-4630 Bochum, Germany. RP Fischer, RA, Ruhr Univ Bochum, Lehrstuhl Anorgan Chem Organomet & Mat Chem 2, Univ Str 150, D-4630 Bochum, Germany. EM roland.fischer@ruhr-uni-bochum.de NR 34 TC 1 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 1477-9226 J9 DALTON TRANS JI Dalton Trans. PY 2006 IS 1 BP 121 EP 128 PG 8 SC Chemistry, Inorganic & Nuclear GA 993PU UT ISI:000233968200013 ER PT J AU Banerjee, S Shi, YH Cao, CS Odom, AL TI Titanium-catalyzed iminohydrazination of alkynes SO JOURNAL OF ORGANOMETALLIC CHEMISTRY LA English DT Article DE hydroamination; hydrohydrazination; iminoamination; imincohydrazination; titanium; catalysis ID INTERMOLECULAR HYDROAMINATION REACTIONS; ALPHA-HYDROGEN ABSTRACTION; INTRAMOLECULAR HYDROAMINATION; CONVENIENT SYNTHESIS; TERMINAL ALKYNES; IMIDOZIRCONOCENE COMPLEXES; MULTICOMPONENT REACTIONS; YTTRIUM COMPLEXES; IMIDO COMPLEXES; AMIDO COMPLEXES AB Titanium pyrrolyl complexes Ti(NMe2)(2)(dap)(2) (1), where dap is 2-(N,N-dimethylaminomethyl)pyrrolyl, and Ti(NMe2)(3)(bap) (3), where bap is 2,5-bis(N,N-dimethylaminomethyl)pyrrolyl, were found to be effective catalysts for the iminohydrazination of alkynes, a new multicomponent coupling reaction involving an alkyne, hydrazine, and isonitrile. A brief study on the scope of the reaction suggests that it is applicable to internal and terminal alkynes, alkyl and aryl isonitriles, and alkyl- and aryl-containing 1,1-disubstituted hydrazines. The best yields were obtained with terminal alkynes and alkyl isonitriles. The regioselectivity of the reactions is quite sensitive to catalyst structure, and, in all cases, we were able to obtain one regioisomer of the iminohydrazination product with either I or 3 as catalyst. The conformation of the products was probed by NMR spectroscopy and DFT calculations, which suggest that the s-cis isomer of the hydrazone-enamine tautomer is the most favorable configuration. However, several configurations are probably accessible in solution at room temperature. Reaction of 1 with 2 equivalents of H2NNMe2 results in the formation of a dinuclear complex Ti-2(dap)(3)(NNMe2)(2)(NHNMe2) (4). where one dap ligand was removed protolytically. Examination of regioselectivities in iminohydrazination reactions using 4 and mono(dap) complex Ti(dap)(NMe2)(3) (5) are consistent with these species using the same catalytic cycle as 1. Consequently, the active species is likely a mono(dap) titanium complex. Current mechanistic information is consistent with a hydrazido(2-) intermediate and a pathway reminiscent of the Bergman hydroamination mechanism. Ti(NMe2)(3)(bap) (3) and Ti-2(daP)(3)(NNMe2)(2)(NHNMe2) (4) were characterized by X-ray diffraction. (c) 2005 Elsevier B.V. All rights reserved. C1 Michigan State Univ, Dept Chem, E Lansing, MI 48824 USA. RP Odom, AL, Michigan State Univ, Dept Chem, E Lansing, MI 48824 USA. EM odom@cem.msu.edu NR 68 TC 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0022-328X J9 J ORGANOMET CHEM JI J. Organomet. Chem. PD NOV 15 PY 2005 VL 690 IS 23 SI Sp. Iss. SI BP 5066 EP 5077 PG 12 SC Chemistry, Inorganic & Nuclear; Chemistry, Organic GA 985CJ UT ISI:000233353400007 ER PT J AU Lazarin, AM Airoldi, C TI Synthesis and electrochemical properties of meldola blue intercalated into barium and calcium phosphates SO SENSORS AND ACTUATORS B-CHEMICAL LA English DT Article DE meldola blue; barium phosphate; calcium phosphate; intercalation; cyclic voltammetry; hydrazine ID ALPHA-TITANIUM HYDROGENPHOSPHATE; REDUCED NICOTINAMIDE COENZYMES; ELECTROCATALYTIC OXIDATION; ZIRCONIUM-PHOSPHATE; METHYLENE-BLUE; GRAPHITE-ELECTRODES; HYDROGEN PHOSPHATE; NADH; ALKYLAMINE; OXIDE AB Meldola blue (MLB) was strongly retained inside the cavity of host layered barium and calcium phosphates, without leaching, and the intercalated compounds were characterized through elemental analysis, X-ray power diffraction (XRD), infrared spectroscopy, scanning electron microscopy, phosphorus nuclear magnetic resonance and electrochemical measurements. The intercalated dye compound was incorporated into a carbon paste electrode and, by means of cyclic voltammetry, its electrochemical properties were investigated. Upon changing the pH of the solution between 2.5 and 7.0, the midpoint potential remained practically constant, giving near -0.020 and -0.019 V versus SCE for barium and calcium phosphates intercalated with MLB. This is not the usual behavior of MLB since its midpoint potential changes considerably in solution phase as the pH is changed. The modified electrodes have proven to be stable and electrocatalytically active for hydrazine oxidation at pH 6.0. (c) 2004 Elsevier B.V. All rights reserved. C1 Univ Estadual Campinas, Inst Quim, BR-13084971 Campinas, SP, Brazil. RP Airoldi, C, Univ Estadual Campinas, Inst Quim, Caixa Postal 6154, BR-13084971 Campinas, SP, Brazil. EM airoldi@iqm.unicamp.br NR 28 TC 4 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-4005 J9 SENSOR ACTUATOR B-CHEM JI Sens. Actuator B-Chem. PD MAY 27 PY 2005 VL 107 IS 1 BP 446 EP 453 PG 8 SC Chemistry, Analytical; Electrochemistry; Instruments & Instrumentation GA 933XH UT ISI:000229665700064 ER PT J AU Squire, MD Davis, RA Chianakas, KA Ferrence, GM Standard, JM Hitchcock, SR TI Synthesis, X-ray crystallography and computational studies concerning an oxadiazinone derived from D-camphor: a structural limitation of oxadiazinones as chiral auxiliaries SO TETRAHEDRON-ASYMMETRY LA English DT Article ID DIELS-ALDER REACTIONS; ALDOL REACTIONS; N-ACYLOXAZOLIDINONES; ASYMMETRIC-SYNTHESIS; TITANIUM ENOLATE; IMINES; RELAY; CYCLOADDITIONS; ACIDS AB A camphor-based oxadiazinone was prepared by reaction of the N-nitroimine of D-camphor with (1R,2S)-norephedrine; the reduction of the resultant imine; N-nitrosation of the amine; reduction to the corresponding hydrazine and cyclization. The conformational behaviour of oxadiazinone 7 was modeled in the gas and solution phases using the semiempirical AM1 method and density functional theory. Application of the oxadiazinone in the titanium mediated asymmetric aldol reaction provided the highly diastereoselective formation of the expected syn-adducts 8a-d as evidenced by single crystal X-ray diffraction analysis. Attempts to remove the oxadiazinone auxiliary using acidic or basic conditions failed to yield the expected beta-hydroxyacid in significant yield. (C) 2005 Elsevier Ltd. All rights reserved. C1 Illinois State Univ, Dept Chem, Normal, IL 61790 USA. RP Ferrence, GM, Illinois State Univ, Dept Chem, Normal, IL 61790 USA. EM gferren@ilstu.edu hitchcock@ilstu.edu NR 32 TC 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0957-4166 J9 TETRAHEDRON-ASYMMETRY JI Tetrahedron: Asymmetry PD MAR 7 PY 2005 VL 16 IS 5 BP 1047 EP 1053 PG 7 SC Chemistry, Inorganic & Nuclear; Chemistry, Organic; Chemistry, Physical GA 904OW UT ISI:000227508600018 ER PT J AU Wei, YZ Fang, B Arai, T Kumagai, M TI Electrochemical reduction of uranium(VI) in nitric acid-hydrazine solution on glassy carbon electrode SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article ID TITANIUM ELECTRODE; MEDIA; IONS AB Electrochemical reduction of U(VI) in nitric acid hydrazine solution is greatly influenced by the concentration of nitric acid. In low acidity nitric acid solution such as 0.1M (M=mol/dm(3)) HNO3, U(VI) was firstly reduced to U(V) and then partially reduced to U(IV). In high acidity nitric acid solution, e.g., 3-6M HNO3, an electrode process of two-electron transfer was involved in the reduction of U(VI). A higher U(IV) yield could be achieved in nitric acid solution with higher concentration. Hydrazine was very effective in suppressing the reduction of concentrated nitric acid, and the optimal concentration of hydrazine added was 0.075 to 0.15M in 6M HNO3 solution. C1 Nucl Chem & Chem Engn Ctr, Inst Res & Innovat, Chiba 2770861, Japan. RP Wei, YZ, Nucl Chem & Chem Engn Ctr, Inst Res & Innovat, 1201 Takada, Chiba 2770861, Japan. EM yzwei@iri.or.jp NR 11 TC 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0236-5731 J9 J RADIOANAL NUCL CHEM JI J. Radioanal. Nucl. Chem. PY 2004 VL 262 IS 2 BP 409 EP 415 PG 7 SC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology GA 867QR UT ISI:000224857800014 ER PT J AU Li, YH Shi, YH Odom, AL TI Titanium hydrazido and imido complexes: Synthesis, structure, reactivity, and relevance to alkyne hydroamination SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Review ID N-N BOND; C-H ACTIVATION; TUNGSTEN (1-PYRIDINIO)IMIDO COMPLEXES; REDUCTIVE ELIMINATION-REACTIONS; NITROGEN-FIXATION PROCESSES; X-RAY STRUCTURE; DINITROGEN RESIDUES; END-ON; INTERMOLECULAR HYDROAMINATION; CATALYTIC HYDROAMINATION AB Treatment of Ti(NMe2)(2)(dpma) (1) with aniline results in the protonation of the dimethylamido ligands, which are retained as dimethylamines, and generation of a titanium imido complex Ti(NPh)(NHMe2)(2)(dpma) (2) in 94% yield. The monomeric imido 2 is converted to the reactive dimeric mu-imido [Ti(NPh)(dpma)](2) (3) on removal of the labile dimethylamine donors. The dimer 3 is converted to monomeric terminal imido complexes in the presence of added donors, e.g., 4,4'-di-tert-butyl-2,2'-bipyridine (Bu-t-bpy) and DME. Compounds 1-3 exhibit the same rate constant for 1-phenylpropyne hydroamination by aniline and are all kinetically competent to be involved in the catalytic cycle. Attempts to use 1 as a catalyst for hydroaminations involving 1, 1-dimethylhydrazine resulted in only a few turnovers under the best conditions. Consequently, the chemistry of 1 with hydrazines to generate hydrazido complexes was scrutinized for comparison with the imido species. Through these studies, titanium hydrazido complexes including Ti(eta(2)-NHNC5H10)(2)(dpma) (5), Ti(eta(2)-NHNMe2)(2)(dpma) (6), and [Ti(mu:eta(1),eta(2)-NNMe2)(dpma)](2) (7) were characterized. In addition, a terminal hydrazido(2-) complex was available by addition of Bu-1-bpy to 1 prior to 1, 1-dimethylhydrazine addition, which provided Ti(eta(1)-NNMe2)(Bu-t-bpy)(dpma) (8). Compound 8 was structurally characterized and compared to Ti(NPh)(Bu-t-bpy)(dpma) (4b), an imido derivative with the same ancillary ligand set. Compound 8 has a nucleophilic beta-nitrogen consistent with a hydrazido(2-) formulation, as determined by reaction with Mel to form the ammonium imido complex [Ti(NNMe3)(Bu-t-bpy)(dpma)]\ (9). Analogous pyridinium imido complexes [Ti(N-1 -pyridinium)(Bu-t-bpy)(dpma)](+) (10) are available by addition of 1-aminopyridinium iodide to 1. From the investigations, some conclusions regarding the activity of titanium pyrrolyl complexes in hydroamination were drawn. The lack of conversion of the bis[mu-hydrazido(2-)] 7 to monomeric species in the presence of donor ligands is put forth as one explanation for the poor hydrazine hydroamination activity of 1. This problem was combated in the synthesis of Ti(NMe2)(2)(dap)(2), which is an active catalyst for hydrazine hydroamination of alkynes. C1 Michigan State Univ, Dept Chem, E Lansing, MI 48824 USA. RP Odom, AL, Michigan State Univ, Dept Chem, E Lansing, MI 48824 USA. EM odom@cem.msu.edu NR 110 TC 36 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD FEB 18 PY 2004 VL 126 IS 6 BP 1794 EP 1803 PG 10 SC Chemistry, Multidisciplinary GA 773MB UT ISI:000188926600049 ER PT J AU Kim, IS Kumta, PN TI Hydrazide sol-gel synthesis of nanostructured titanium nitride: precursor chemistry and phase evolution SO JOURNAL OF MATERIALS CHEMISTRY LA English DT Article ID CHEMICAL-VAPOR-DEPOSITION; LOW-TEMPERATURE SYNTHESIS; COMBUSTION SYNTHESIS; TRANSITION-METALS; ALUMINUM NITRIDE; TIN; POWDERS; COMPLEXES; DISULFIDE; FILMS AB A hydrazide sol - gel (HSG) process has been developed for synthesizing nanostructured titanium nitride. The process consists of reacting titanium isopropoxide with anhydrous hydrazine in the presence of anhydrous acetonitrile to yield a solid titanium alkoxy hydrazide precursor. Gas chromatography supported by chemical analysis shows that similar to80% of the isopropoxy groups are replaced by hydrazine. The role of acetonitrile, used as a solvent in the formation of titanium alkoxy hydrazide, has been studied using thermogravimetric and mass spectrometry analyses combined with chemical analysis and Fourier transform infrared spectroscopy techniques. Crystalline TiN has been obtained after heat-treatment at temperatures above 800 degreesC in ultra high purity nitrogen (UHP-N-2) and UHP-Ar atmospheres. Transmission electron microscopy and specific surface area analyses revealed that the TiN powder obtained after pyrolysis in UHP-N-2 at 1200 degreesC consists of nanocrystalline (similar to10-20 nm) particles exhibiting a high specific surface area ( similar to252 m(2) g(-1)). C1 Carnegie Mellon Univ, Dept Mat Sci & Engn, Pittsburgh, PA 15213 USA. RP Kumta, PN, Carnegie Mellon Univ, Dept Mat Sci & Engn, Pittsburgh, PA 15213 USA. NR 50 TC 7 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 0959-9428 J9 J MATER CHEM JI J. Mater. Chem. PY 2003 VL 13 IS 8 BP 2028 EP 2035 PG 8 SC Chemistry, Physical; Materials Science, Multidisciplinary GA 703XU UT ISI:000184308500031 ER PT J AU Kim, IS Kumta, PN TI Hydrazide sol-gel process: A novel approach, for synthesizing nanostructured titanium nitride SO MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY LA English DT Article DE hydrazine; nanocrystalline; gas chromatography ID CHEMICAL-VAPOR-DEPOSITION; TIN THIN-FILMS; ALUMINUM NITRIDE; COMBUSTION SYNTHESIS; PRECURSORS; POWDERS; DISULFIDE; CERAMICS; NIOBIUM; PLASMA AB A novel hydrazide sol-gel process has been developed to synthesize nanocrystalline titanium nitride. The process involves the reaction of titanium isopropoxide with anhydrous hydrazine in the presence of anhydrous acetonitrile to yield a solid precursor. Gas chromatography supported by chemical analysis shows that approximate to 80% of the isopropoxy groups are replaced by hydrazine. Nanostructured TiN is seen to evolve when the as-prepared precursor is pyrolyzed in ultra high purity (UHP) N-2, UHP-Ar and NH3 at a temperature as low as 600 degreesC. However, fully crystallized single phase TiN is detected by X-ray diffraction at a temperature of 800 degreesC. Transmission electron microscopy and specific surface area analyses revealed that TiN obtained after pyrolysis in UHP-N-2 is nanocrystalline ( < 100 nm) exhibiting a high specific surface area ( congruent to 250 m(2) g(-1)). (C) 2002 Elsevier Science B.V. All rights reserved. C1 Carnegie Mellon Univ, Dept Mat Sci & Engn, Pittsburgh, PA 15213 USA. RP Kumta, PN, Carnegie Mellon Univ, Dept Mat Sci & Engn, Pittsburgh, PA 15213 USA. NR 51 TC 4 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5107 J9 MATER SCI ENG B-SOLID STATE M JI Mater. Sci. Eng. B-Solid State Mater. Adv. Technol. PD MAR 15 PY 2003 VL 98 IS 2 BP 123 EP 134 PG 12 SC Materials Science, Multidisciplinary; Physics, Condensed Matter GA 676XM UT ISI:000182777900007 ER PT J AU Timoshkin, AY Siodmiak, M Korkin, AA Frenking, G TI Formation of oligomer species in the course of the TiCl4 ammonolysis and their role in Ti(IV)-Ti(III) reduction processes: A theoretical study SO COMPUTATIONAL MATERIALS SCIENCE LA English DT Article DE TiN; chemical vapor deposition; oligomerization reactions; modelling; quantum chemistry ID CHEMICAL-VAPOR-DEPOSITION; GAS-PHASE REACTIONS; TITANIUM NITRIDE AB Gas phase oligomer formation during TiCl4 ammonolysis is theoretically investigated at the DFT B3LYP level of theory with double-zeta quality basis set. Several possible isomers of the dimeric [TiClxNHx-1(NH3)(n)](2) species (x = 3, 2; n = 0, 1) have been considered. Dimerization of amido compounds is exothermic by about 10 kcal mol(-1), but disfavored by entropy. The latter factor prevents the existence of the amido dimers in the gas phase thermodynamic equilibrium. The dimerization processes of imido compounds are much more exothermic (by about 94 kcal mol(-1)). A cubic [ClTiN](4) cluster is predicted to be a viable molecular form in the gas phase above 1400 degreesC. Reduction of Ti(IV) to Ti(III) via hydrazine formation from the [TiCl3NH2(NH3)](2) dimers is less endothermic (similar to40 kcal mol(-1)) than Ti-Cl bond rupture (similar to82.5 kcal mol(-1)). The overall endothermicity of the formation of N2H4 bridged Ti(III) dimer [Cl-2(H3N)Ti(mu-Cl)(2)(mu-N2H4)Ti(NH3)Cl-2] from TiCl4 and NH3 is only 6.6 kcal mol(-1). Additional coordination of two ammonia molecules to the [Cl3TiNH2](2) dimer facilitates the elimination of Cl atom. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Marburg, Fachbereich Chem, D-35032 Marburg, Germany. Motorola Inc, Adv Syst Technol Lab, Mesa, AZ 85202 USA. RP Timoshkin, AY, Univ Marburg, Fachbereich Chem, D-35032 Marburg, Germany. NR 16 TC 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0256 J9 COMPUT MATER SCI JI Comput. Mater. Sci. PD MAR PY 2003 VL 27 IS 1-2 BP 109 EP 116 PG 8 SC Materials Science, Multidisciplinary GA 657GA UT ISI:000181656700019 ER PT J AU Albrecht, M Kamptmann, S Frohlich, R TI 3,3 '-{(1E,2E)-hydrazine-1,2-diylidenedi[(E)methylylidene]}dibenzene-1,2-dio l (BCAz-H-4): an easy to prepare but very useful building block for the self-assembly of triple-stranded helicates; the X-ray crystal structure of Na-4[(BCAz)(3)Ti-2]center dot 7 dmf center dot H2O SO POLYHEDRON LA English DT Article DE crystal structure; dicatechol; helicate ID INEXPENSIVE APPROACH; DOUBLE HELIX; COORDINATION; LIGANDS; COMPLEXES; CHEMISTRY AB The azine bridged dicatechol ligand BCAz-H-4 forms triple-stranded dinuclear helicates with titanium(IV) ions in the presence of alkali metal carbonate. The X-ray structure of Na-4[(BCAz)(3)Ti-2].7 dmf.H2O shows that countercations can be encapsulated in the interior of the helicate binding not only to internal oxygen atoms of the catecholates but also to nitrogen atoms of the spacer. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Rhein Westfal TH Aachen, Inst Organ Chem, D-52074 Aachen, Germany. Univ Munster, Inst Organ Chem, D-48149 Munster, Germany. RP Albrecht, M, Rhein Westfal TH Aachen, Inst Organ Chem, Prof Pirlet Str 1, D-52074 Aachen, Germany. EM markus.albrecht@oc.rwth-aachen.de NR 30 TC 10 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0277-5387 J9 POLYHEDRON JI Polyhedron PD MAR 1 PY 2003 VL 22 IS 5 BP 643 EP 647 PG 5 SC Chemistry, Inorganic & Nuclear; Crystallography GA 654VU UT ISI:000181517400002 ER PT J AU Rusina, O Linnik, O Eremenko, A Kisch, H TI Nitrogen photofixation on nanostructured iron titanate films SO CHEMISTRY-A EUROPEAN JOURNAL LA English DT Article DE nanostructures; nitrogen fixation; photochemistry; thin films; titanates ID TITANIUM-DIOXIDE CATALYSTS; HYDROGEN EVOLVING SYSTEMS; FLUIDIZED-BED REACTOR; DOPED TITANIA; HETEROGENEOUS PHOTOREDUCTION; DINITROGEN PHOTOREDUCTION; PHOTOCATALYTIC REDUCTION; PHOTOASSISTED PROCESSES; MOLECULAR NITROGEN; CHEMICAL ENERGY AB A nanostructured iron titanate thin film has been prepared by a sol-gel method from iron(III) chloride and titanium tetra isopropyl ate. Energy-dispersive X-ray analysis and Mossbauer spectroscopy suggest the presence of a Fe2Ti2O7 phase, which was previously obtained as an intermediary phase upon heating ilmenite. In the presence of ethanol or humic acids and traces of oxygen, the novel film photocatalyzes the fixation of dinitrogen to ammonia (17 muM) and nitrate (45 muM). In the first observable reaction step, hydrazine is produced and then undergoes further photoreduction to ammonia. Oxidation of the latter by oxygen affords nitrate as the final product. Since the reaction occurs also in air and with visible light (lambda > 455 nm), and since the iron titanate phase may be formed by the weathering of ilmenite minerals, it may be a model for mutual nonenzymatic nitrogen fixation in nature. C1 Univ Erlangen Nurnberg, Inst Anorgan Chem, D-91058 Erlangen, Germany. Natl Acad Sci Ukraine, Inst Surface Chem, UA-03164 Kiev, Ukraine. RP Kisch, H, Univ Erlangen Nurnberg, Inst Anorgan Chem, Egerlandstr 1, D-91058 Erlangen, Germany. NR 41 TC 10 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 0947-6539 J9 CHEM-EUR J JI Chem.-Eur. J. PD JAN 20 PY 2003 VL 9 IS 2 BP 561 EP 565 PG 5 SC Chemistry, Multidisciplinary GA 638VD UT ISI:000180592000022 ER PT J AU Dave, S Singh, RV Joshi, SC Jaroli, DP TI Novel bioactive thio- and semi-carbazide ligands and their organotitanium(IV) and organozirconium(IV) complexes SO ASIAN JOURNAL OF CHEMISTRY LA English DT Article DE organotitanium; organo-zirconium; complexes; semicarbazide; thiosemicarbazide ID TITANIUM; POLYMERIZATION; CATALYSTS; OXYGEN AB Organotitanium(IV) and organozirconium(IV) complexes have been synthesized by the reaction of titanocenedichloride or zirconocenedichloride with two different ketimines in the presence of triethylamine. In all the reactions the imines behave as monobasic bidentate ligands. The resulting complexes Cp2M(L)(L') [where Cp = cyclopentadienyl ring, L = 2-[1-(2-thienyl)ethyledene]hydrazine-carbothiomide and L'=2-[1-(2-thienyl)ethyledene]hydrazine-carboxamide, 2-[1-(2-naphthenyl)ethyledene]hydrazine-carbothiomide, and 2-[I-(2-naphthenyl)ethyledene]hydrazine-carboxamide have been characterized by elemental analysis and IR and H-1 NMR spectral studies. Based on these spectral studies, an octahedral structure has been proposed for all the complexes. The antifungal, antibacterial and antifertility activities of the ligands; and their complexes have also been carried out. C1 Univ Rajasthan, Dept Chem, Jaipur 302004, Rajasthan, India. NR 27 TC 0 PU MRS PUSHPA AGARWAL PI SAHIBABAD PA 11/100 RAJENDRA NAGAR, SECTOR 3,, SAHIBABAD 201 005, GHAZIABAD, INDIA SN 0970-7077 J9 ASIAN J CHEM JI Asian J. Chem. PD JAN-MAR PY 2003 VL 15 IS 1 BP 359 EP 365 PG 7 SC Chemistry, Multidisciplinary GA 621XG UT ISI:000179615800063 ER PT J AU Reddy, KM Manorama, SV Reddy, AR TI Bandgap studies on anatase titanium dioxide nanoparticles SO MATERIALS CHEMISTRY AND PHYSICS LA English DT Article DE anatase titanium dioxide; nanoparticles; blue shift; optical properties; bandgap ID SEMICONDUCTOR; PHOTOCATALYSIS; TIO2 AB Titanium dioxide, predominantly in the anatase phase with an average grain size of 5-10 nm, has been synthesized by the hydrazine method. These nanocrystalline particles show a blue shift in the absorption edge of the diffuse reflectance ultraviolet spectrum of about 10 nm compared to that of commercially available titania. Synthesized samples were characterized by X-ray diffraction and transmission electron microscopy for their structural properties and UV-Vis absorption spectroscopy for the bandgap studies. The absorption spectra show a linear fit for the direct transition. The optical and electrical properties of the samples have been studied and the Arrhenius plots of electrical conductivity both for the as-prepared anatase TiO2 and the one subsequently reduced in hydrogen atmosphere at 673 K show a distinct difference in the activation energy. The hydrogen-annealed sample shows a typical semiconducting behavior whereas the as-prepared sample indicates a phonon contribution to the conductivity around 300 K. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Indian Inst Chem Technol, Mat Sci Grp, Hyderabad 500007, Andhra Pradesh, India. Reg Engn Coll, Dept Phys, Warangal, Andhra Pradesh, India. RP Manorama, SV, Indian Inst Chem Technol, Mat Sci Grp, Hyderabad 500007, Andhra Pradesh, India. NR 22 TC 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0254-0584 J9 MATER CHEM PHYS JI Mater. Chem. Phys. PD FEB 3 PY 2003 VL 78 IS 1 BP 239 EP 245 PG 7 SC Materials Science, Multidisciplinary GA 615TK UT ISI:000179262700040 ER PT J AU Rao, CRK Pushpavanam, M TI Electroless deposition of platinum on titanium substrates SO MATERIALS CHEMISTRY AND PHYSICS LA English DT Article DE electroless deposition; synergistic effect; stress-free deposit; surface tension; stabiliser AB The use of an electroless platinum bath based on chloroplatinic acid and hydrazine for depositing adherent and uniform layers on titanium panels is demonstrated. The conditions were optimised for a new set of additives. The effect of concentrations of platinum metal in the bath on thickness of the deposit was studied. The deposition rates on titanium and gold-plated titanium are evaluated. Dispersed platinum coatings on titanium powder were successfully obtained. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Cent Electrochem Res Inst, Karaikudi 630006, Tamil Nadu, India. RP Pushpavanam, M, Cent Electrochem Res Inst, Karaikudi 630006, Tamil Nadu, India. NR 6 TC 4 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0254-0584 J9 MATER CHEM PHYS JI Mater. Chem. Phys. PD FEB 15 PY 2001 VL 68 IS 1-3 BP 62 EP 65 PG 4 SC Materials Science, Multidisciplinary GA 397GM UT ISI:000166685000009 ER PT J AU Enders, D Ullrich, EC TI Asymmetric pinacol coupling of aromatic aldehydes with TiCl2/enantiopure amine or hydrazine reagents SO TETRAHEDRON-ASYMMETRY LA English DT Article ID STEREOSELECTIVE PINACOLIZATION; ENANTIOSELECTIVE SYNTHESIS; ISOINVERSION PRINCIPLE; TITANIUM TRICHLORIDE; KETONES; HYDROSILYLATION; REASSESSMENT; ALKYLATION; COMPLEXES; REDUCTION AB Asymmetric pinacol coupling of aromatic aldehydes under homogeneous conditions with TiCl2 in the presence of enantiopure amines or hydrazines afforded 1,2-diols in moderate to excellent yields with good dl-diastereoselectivities and enantioselectivities in the range of 6-65% ee. A non-linear temperature effect ('principle of isoinversion') has been examined. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Rhein Westfal TH Aachen, Inst Organ Chem, D-52074 Aachen, Germany. RP Enders, D, Rhein Westfal TH Aachen, Inst Organ Chem, Prof Pirlet Str 1, D-52074 Aachen, Germany. NR 42 TC 23 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0957-4166 J9 TETRAHEDRON-ASYMMETRY JI Tetrahedron: Asymmetry PD OCT 6 PY 2000 VL 11 IS 19 BP 3861 EP 3865 PG 5 SC Chemistry, Inorganic & Nuclear; Chemistry, Organic; Chemistry, Physical GA 379TQ UT ISI:000165658900004 ER PT J AU Amato-Wierda, C Wierda, DA TI Chemical vapor deposition of titanium nitride thin films from tetrakis(dimethylamido)titanium and hydrazine as a coreactant SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID TETRAKIS-DIMETHYLAMINO-TITANIUM; ADVANCED BARRIER LAYERS; MICROELECTRONICS INDUSTRY; IMIDO COMPLEXES; TIN; PRESSURE; PRECURSOR; AMMONIA; DIFFUSION; CONTACT AB Hydrazine was used as a coreactant with tetrakis(dimethylamido)titanium for the low-temperature chemical vapor deposition of TiN between 50 and 200 degreesC. The TiN film-growth rates ranged from 5 to 45 nm/min. Ti:N ratios of approximately 1:1 were achieved. The films contain between 2 and 25 at.% carbon, as well as up to 36 at.% oxygen resulting from diffusion after air exposure. The resistivity of these films is approximately 10(4) mu Omega cm. Annealing the films in ammonia enhances their crystallinity. The best TiN films were produced at 200 degreesC from a 2.7% hydrazine-ammonia mixture. The Ti:N ratio of these films is approximately 1:1, and they contain no carbon or oxygen. These films exhibit the highest growth rates observed. C1 Univ New Hampshire, Mat Sci Program, Durham, NH 03824 USA. St Anselms Coll, Dept Chem, Manchester, NH 03102 USA. RP Amato-Wierda, C, Univ New Hampshire, Mat Sci Program, Durham, NH 03824 USA. NR 41 TC 2 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD NOV PY 2000 VL 15 IS 11 BP 2414 EP 2424 PG 11 SC Materials Science, Multidisciplinary GA 373EL UT ISI:000165275400024 ER PT J AU Goetze, B Knizek, J Noth, H Schnick, W TI 1,2-bis(trimethylsilyl)hydrazido titanium complexes SO EUROPEAN JOURNAL OF INORGANIC CHEMISTRY LA English DT Article DE bis(trimethylsilyl)hydrazine; hydrazido complexes; nitrides; titanium; tris(trimethylsilyl)hydrazine ID CRYSTAL-STRUCTURE; CHEMISTRY AB The silylhydrazido titanium complexes [Cl2Ti(N2H(SiMe3)(2))(2)] (1), [ClTi(N2H(SiMe3)(2))(3)] (2), and [(ClTi)(2)(N-2(SiMe3))(2)] (3) have been synthesized by reactions of the appropriate (trimethylsilyl)hydrazines with TiCl4 in solution. The reactions are driven by the elimination of Me3SiCl or LiCl after the dilithiation of bis(trimethylsilyl)hydrazine. According to NMR, mass spectrometry, and X-ray structure determination, products 1 and 2 are formed by the reaction of one equivalent of TiCl4, with two or three equivalents of hydrazine, whereas compound 3 results from the reaction of two equivalents of TiCl4 with two equivalents of hydrazine. According to the results of single-crystal X-ray diffraction investigations, complexes 1 and 3 feature an eta(2)-coordination of the hydrazido moiety to the titanium. In the crystals of 3, both a chair and a twist form of the six-membered TiN2TiN2 rings are found, corresponding to different donor coordination modes of the hydrazido ligands to titanium. Temperature-dependent Si-29 NMR investigations indicate that both coordination modes co-exist in solution at low temperatures, but not at room temperature. C1 Univ Munich, Dept Chem, D-81377 Munich, Germany. RP Schnick, W, Univ Munich, Dept Chem, Butenandtstr 5-13,Haus D, D-81377 Munich, Germany. NR 14 TC 4 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 1434-1948 J9 EUR J INORG CHEM JI Eur. J. Inorg. Chem. PD AUG PY 2000 IS 8 BP 1849 EP 1854 PG 6 SC Chemistry, Inorganic & Nuclear GA 338AV UT ISI:000088396700024 ER PT J AU Ferreira, CU Gushikem, Y Kubota, LT TI Electrochemical properties of Meldola's Blue immobilized on silica-titania phosphate prepared by the sol-gel method SO JOURNAL OF SOLID STATE ELECTROCHEMISTRY LA English DT Article DE silica-titania phosphate; sol-gel processing; Meldola's Blue; carbon paste electrode; hydrazine electrooxidation ID CONDUCTING SUBSTRATE BASE; ELECTROCATALYTIC OXIDATION; NICKEL HEXACYANOFERRATE; GRAPHITE-ELECTRODES; ZIRCONIUM-PHOSPHATE; TITANIUM(IV) OXIDE; SURFACE; SENSOR; NADH; BIOSENSOR AB The mixed oxide phosphate (=SiO)(2)Ti(O3POH)(2) having a specific surface area of S-BET = 595 m(2) g(-1) and an average pore volume of 0.43 mL g(-1) was prepared by the sol-gel processing method. The material showed the following characteristics: Ti = 11.6 wt% and P = 10.5 wt%; ion exchange capacity of 0.60 mmol g(-1). Meldola's Blue (MLB) dye was adsorbed, by an ion exchange reaction, from an aqueous solution in a quantity of 0.62 mmol g(-1). The dye was strongly retained and was not easily leached from the matrix even in presence of 0.5 M electrolyte solution. Changing the solution pH between 2.5 and 7.0, the midpoint potential of the dye-adsorbed (=SiO)(2) Ti(O3POMLB)(2) matrix carbon paste electrode remained practically constant, i.e. about 20 mV vs. SCE. This is not the usual behaviour of MLB since its midpoint potential changes considerably in solution phase as the pH is changed. The modified electrode has proved to be stable and electrocatalytically active for hydrazine oxidation at pH 6. C1 UNICAMP, Inst Quim, BR-13083970 Campinas, SP, Brazil. RP Gushikem, Y, UNICAMP, Inst Quim, CP 6154, BR-13083970 Campinas, SP, Brazil. NR 28 TC 18 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1432-8488 J9 J SOLID STATE ELECTROCHEM JI J. Solid State Electrochem. PD MAY PY 2000 VL 4 IS 5 BP 298 EP 303 PG 6 SC Electrochemistry GA 320EG UT ISI:000087388400006 ER PT J AU Matsumoto, T Murakami, Y Takasu, Y TI Photochromism of titanium oxide gels prepared by the salt-catalytic sol-gel process SO CHEMISTRY LETTERS LA English DT Article ID TETRA-N-BUTOXIDE; TIO2; CATIONS AB Photochromism for the monolithic gel of titanium oxide prepared by the catalytic sol-gel process was observed. When hydrazine monohydrochloride was used as a catalyst, an intense blue color development was observed with the formation of Ti3+ on the irradiation of UV light (< ca. 350 nm). The degree of coloration and the recovery time were strongly affected by a kind of salt catalysts although the color was independent. Presence of active salt catalysts in the gel was indispensable for color development. C1 Shinshu Univ, Fac Text Sci & Technol, Dept Fine Mat Engn, Ueda, Nagano 3868567, Japan. RP Murakami, Y, Shinshu Univ, Fac Text Sci & Technol, Dept Fine Mat Engn, 3-15-1 Tokida, Ueda, Nagano 3868567, Japan. NR 24 TC 7 PU CHEMICAL SOC JAPAN PI TOKYO PA 1-5 KANDA-SURUGADAI CHIYODA-KU, TOKYO, 101, JAPAN SN 0366-7022 J9 CHEM LETT JI Chem. Lett. PD APR 5 PY 2000 IS 4 BP 348 EP 349 PG 2 SC Chemistry, Multidisciplinary GA 310NF UT ISI:000086833700026 ER PT J AU Waki, K Zhao, JC Horikoshi, S Watanabe, N Hidaka, H TI Photooxidation mechanism of nitrogen-containing compounds at TiO2/H2O interfaces: an experimental and theoretical examination of hydrazine derivatives SO CHEMOSPHERE LA English DT Article DE photooxidation; photodegradation; hydrazine; photocatalysis; titanium dioxide; gas-generating agent ID PHOTOCATALYTIC DEGRADATION; ORGANIC-COMPOUNDS; TITANIUM-DIOXIDE; WATER INTERFACE; NO3 IONS; OXIDATION; MINERALIZATION; AMMONIUM; NITRATE; NH4+ AB The photocatalytic oxidation of oxalyldihydrazide, N, N'-bis(hydrazocarbonyl)hydrazide, N, N'-bis(ethoxycarbonyl)hydrazide, malonyldihydrazide, N-malonyl-bis[(N'-ethoxycarbonyl)hydrazide] was examined in aqueous TiO2 dispersions under UV illumination. The photomineralization of nitrogen and carbon atoms in the substrates into N-2 gas, NH4+ (and/or NO3-) ions, and CO2 gas was determined by HPLC and GC analysis. The formation of carboxylic acid intermediates also occurred in the photooxidation process. The photocatalytic mechanism is discussed on the basis of the experimental results, and with molecular orbital (MO) simulation of frontier electron density and point charge. Substrate carbonyl groups readily adsorb on the TiO2 surface, and the bonds between carbonyl group carbon atoms and adjacent hydrate group nitrogen atoms are cleaved predominantly in the initial photooxidation process. The hydrate groups were photoconverted mainly into N-2 gas (in mineralization yields above 70%) and partially to NH4+ ions (below 10%). The formation of NO3- ions was scarcely recognized. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Iwaki Meisei Univ, Frontier Res Ctr Global Environm Protect, Hino, Tokyo 1918506, Japan. Chinese Acad Sci, Inst Photog Chem, Beijing 100101, Peoples R China. Toyo Univ, Dept Appl Chem, Fac Engn, Kawagoe, Saitama 3500815, Japan. RP Hidaka, H, Iwaki Meisei Univ, Frontier Res Ctr Global Environm Protect, Hino, Tokyo 1918506, Japan. NR 10 TC 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0045-6535 J9 CHEMOSPHERE JI Chemosphere PD AUG PY 2000 VL 41 IS 3 BP 337 EP 343 PG 7 SC Environmental Sciences GA 309UB UT ISI:000086786700006 ER PT J AU Thorman, JL Woo, LK TI Synthesis and reactivity of hydrazido(2-) and imido derivatives of titanium(IV) tetratolylporphyrin SO INORGANIC CHEMISTRY LA English DT Article ID RAY CRYSTAL-STRUCTURES; CYCLOADDITION REACTIONS; COORDINATION CHEMISTRY; NITROSO-COMPOUNDS; DIAZO-COMPOUNDS; COMPLEXES; MOLYBDENUM; BEHAVIOR; TUNGSTEN; LIGANDS AB Titanium porphyrin hydrazido complexes (TTP)Ti=NNR2 (TTP = meso-tetra-p-tolylporphyrinato dianion; R = Me (1), Ph (2)) were synthesized by treatment of (TTP)TiCl2 with 1,1-disubstituted hydrazines H2NNR2 (R Me, Ph) in the presence of piperidine. The nucleophilic character of the hydrazido moiety was demonstrated in the reactions of complexes 1 and 2 with p-chlorobenzaldehyde, which yielded the titanium oxo complex (TTP)Ti=O and the respective hydrazones. Protonation of complexes 1 and 2 with phenol or water produced the 1,1-disubstituted hydrazine along with (TTP)Ti(OPh)(2) or (TTP)Ti=O, respectively. Similar reactivity of p-chlorobenzaldehyde and phenol with (TTP)Ti=(NPr)-Pr-i, 3, was observed. The reaction of complex 3 with nitrosobenzene cleanly formed the azo compound (PrN)-Pr-i=NPh and the terminal oxo product (TTP)Ti=O. C1 Iowa State Univ, Dept Chem, Ames, IA 50011 USA. RP Woo, LK, Iowa State Univ, Dept Chem, Ames, IA 50011 USA. NR 31 TC 19 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD MAR 20 PY 2000 VL 39 IS 6 BP 1301 EP 1304 PG 4 SC Chemistry, Inorganic & Nuclear GA 297DN UT ISI:000086066600035 ER PT J AU Amato-Wierda, C Norton, ET Wierda, DA TI Low temperature chemical vapor deposition of titanium nitride thin films with hydrazine and tetrakis(dimethylamido)titanium SO ELECTROCHEMICAL AND SOLID STATE LETTERS LA English DT Article ID TETRAKIS-DIMETHYLAMINO-TITANIUM; ADVANCED BARRIER LAYERS; MICROELECTRONICS INDUSTRY; TIN; AMMONIA; PRECURSOR; DIFFUSION; CONTACT; SILICON; GROWTH AB Hydrazine has been used as a precursor along with tetrakis( dimethylamido) titanium (TDMAT) for the low temperature chemical vapor deposition of TiN thin films between 50 and 200 degrees C at 10 Torr, with growth rates between 5 and 35 nm/min. The Ti:N ratio in these films is approximately 1:1. They contain from 2 to 6% carbon, and varying amounts of oxygen up to 36% as a result of diffusion after air exposure. Moreover, low temperature growth is improved with hydrazine-ammonia mixtures containing as little as 1.9% hydrazine. The Ti: N ratio of these films is also approximately 1:1; but they contain no carbon or oxygen according to Rutherford backscattering spectroscopy. The X-ray diffraction of these films grown from pure hydrazine or the hydrazine-ammonia mixture shows peaks corresponding to TiN. The resistivity of the films is on the order of 10(4) mu Omega cm. The low temperature growth is attributed to the weak N-N bond in hydrazine and its strong reducing ability. (C) 1999 The Electrochemical Society. S1099-0062(99)06-112-X. All rights reserved. C1 Univ New Hampshire, Mat Sci Program, Manchester, NH 03102 USA. St Anselms Coll, Dept Chem, Manchester, NH 03102 USA. RP Amato-Wierda, C, Univ New Hampshire, Mat Sci Program, Durham, NH 03824 USA. NR 37 TC 1 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 1099-0062 J9 ELECTROCHEM SOLID STATE LETT JI Electrochem. Solid State Lett. PD DEC PY 1999 VL 2 IS 12 BP 613 EP 615 PG 3 SC Electrochemistry; Materials Science, Multidisciplinary GA 249QN UT ISI:000083343900003 ER PT J AU Leskela, M Ritala, M TI ALD precursor chemistry: Evolution and future challenges SO JOURNAL DE PHYSIQUE IV LA English DT Article ID ATOMIC-LAYER EPITAXY; CHEMICAL-VAPOR-DEPOSITION; OXIDE THIN-FILMS; BINARY REACTION SEQUENCE; IN-SITU; BETA-DIKETONATE; SURFACE-CHEMISTRY; GROWTH; TITANIUM; SILICON AB The requirements of ALD precursors differ from those of CVD concerning thermal stability, adsorption on the surface, and reactions towards each other. In the first ALD experiments in the 70s elements (Zn, Cd, S), metal halides and non-metal hydrides (H2O, H2S) were used. In the 80s the selection of precursors widened to metal complexes (alkoxides, P-diketonates) and simple organometallics (alkyl compounds). In the 90s both new metal (Cp-compounds, alkylamides) as well as non-metal precursors (H2O2, O-3, hydrazine) have been introduced. A characteristic feature of ALD is that surface groups play an important role as reactive sites for tl-le next precursor pulse. The development of ALD precursors is limited by the small number of groups working in the field It seems, however, that the precuror development is diverged and tailored molecules are designed for each process. C1 Univ Helsinki, Dept Chem, Helsinki 00014, Finland. RP Leskela, M, Univ Helsinki, Dept Chem, POB 55, Helsinki 00014, Finland. NR 110 TC 17 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD SEP PY 1999 VL 9 IS P8 PN Part 2 BP 837 EP 852 PG 16 SC Physics, Multidisciplinary GA 235DN UT ISI:000082524900039 ER PT J AU Perez, EF Kubota, LT Tanaka, AA Neto, GD TI Anodic oxidation of cysteine catalysed by nickel tetrasulphonated phthalocyanine immobilized on silica gel modified with titanium(IV) oxide SO ELECTROCHIMICA ACTA LA English DT Article ID METAL-PHTHALOCYANINES; COBALT PHTHALOCYANINE; GRAPHITE-ELECTRODES; HYDRAZINE; REDUCTION; SURFACE; ELECTROCHEMISTRY; ELECTROOXIDATION; POTENTIALS; CHLORIDE AB A chemically modified electrode constructed by mixing nickel tetrasulfonated phthalocyanine (NiTsPc) immobilized on modified silica gel with carbon paste showed a redox process with a midpoint potential of 0.44 V vs see. Experiments carried out with different supporting electrolytes suggested an effect due to the nature of the anion. The solution pH does not affect the midpoint potential but the peak current increases when the pH is decreased. The immobilization procedure causes an increase in the monomeric form of the complex. The electrochemical property of NiTsPc adsorbed onto modified silica showed good stability even in acidic media (pH = 2) and the ability to catalyze the electro-oxidation of cysteine at 0.5 V vs see. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 UNICAMP, Inst Quim, BR-13083970 Campinas, SP, Brazil. Univ Fed Maranhao, Dept Quim, Sao Luiz, MA, Brazil. RP Kubota, LT, UNICAMP, Inst Quim, POB 6154, BR-13083970 Campinas, SP, Brazil. NR 37 TC 26 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0013-4686 J9 ELECTROCHIM ACTA JI Electrochim. Acta PY 1998 VL 43 IS 12-13 BP 1665 EP 1673 PG 9 SC Electrochemistry GA ZU378 UT ISI:000074191100001 ER PT J AU Kim, JY Kumta, PN TI A novel reductive nitrogenation approach for synthesizing aluminum nitride powders SO MATERIALS LETTERS LA English DT Article DE aluminium nitride (AIN); synthesis; aluminum trichloride; hydrazine; reductive nitrogenation; X-ray diffraction (XRD); scanning electron microscopy (SEM) ID TITANIUM DISULFIDE AB A novel low temperature chemical approach has been developed for synthesizing aluminum nitride powders. The process involves the reaction of aluminum trichloride (AlCl3) with anhydrous hydrazine (N2H4) in an acetonitrile solution in the presence of metallic lithium to induce a reductive precipitation reaction. Results of the XRD analyses conducted on the pyrolyzed powders obtained after heat-treatment at 800 degrees C in either UHP-Ar or NH3 indicate the formation of a mixture of hexagonal AIN and lithium chloride (LiCl). LiCl can be removed either by washing with acetone or by subsequent heat-treatment of the precursors in UHP-Ar or NH3 beyond 1000 degrees C, resulting in single-phase hexagonal AlN powders. This new approach therefore demonstrates the potential for synthesizing precursors at room temperature for the subsequent generation of AIN powders at temperatures as low as 800 degrees C. (C) 1998 Elsevier Science B.V. C1 Carnegie Mellon Univ, Dept Mat Sci & Engn, Pittsburgh, PA 15213 USA. RP Kumta, PN, Carnegie Mellon Univ, Dept Mat Sci & Engn, Pittsburgh, PA 15213 USA. EM kumta@cmu.edu NR 22 TC 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-577X J9 MATER LETT JI Mater. Lett. PD MAR PY 1998 VL 34 IS 3-6 BP 188 EP 195 PG 8 SC Materials Science, Multidisciplinary; Physics, Applied GA ZK188 UT ISI:000073294200017 ER PT J AU Urek, S Drofenik, M TI The hydrothermal synthesis of BaTiO3 fine particles from hydroxide-alkoxide precursors SO JOURNAL OF THE EUROPEAN CERAMIC SOCIETY LA English DT Article ID POWDERS AB Fine powders of barium titanate were synthesized hydrothermally from aqueous barium acetate or barium hydroxide and titanium ethoxide solution, with different alkaline media, ammonia, hydrazine and tetramethylammonium hydroxide. Barium titanate powder prepared from Ba(OH)(2) after synthesis shows BaCO3 impurities. On the other hand, powders prepared from Ba(CH3COO)(2), Ti(OC2H5)(4) and tetramethylammonium hydroxide exhibit the smallest average grain size and did not contain BaCO3 impurities. However, a relative by large amount of organic disintegration products which delay the sintering process were identified in the BaTiO3 powders from Pa acetate. The BaTiO3 powders were characterized by scanning electron microscopy (SEM), X-ray diffraction spectroscopy (XRD), thermogravimetric analysis (TGA), mass spectroscopy and dilatometric analyses. (C) 1998 Published by Elsevier Science Limited. C1 Univ Maribor, SLO-2000 Maribor, Slovenia. Jozef Stefan Inst, Ljubljana, Slovenia. RP Urek, S, Univ Maribor, SLO-2000 Maribor, Slovenia. NR 10 TC 24 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0955-2219 J9 J EUR CERAM SOC JI J. European Ceram. Soc. PY 1998 VL 18 IS 4 BP 279 EP 286 PG 8 SC Materials Science, Ceramics GA ZF256 UT ISI:000072879300001 ER PT J AU Perez, EF Neto, GD Tanaka, AA Kubota, LT TI Electrochemical sensor for hydrazine based on silica modified with nickel tetrasulfonated phthalocyanine SO ELECTROANALYSIS LA English DT Article DE sensor; hydrazine; modified electrode; carbon paste ID CARBON-PASTE ELECTRODES; GEL SURFACE; TITANIUM(IV) OXIDE; ELECTROCATALYTIC OXIDATION; METAL PHTHALOCYANINES; GRAPHITE-ELECTRODES; HYDROGEN-PEROXIDE; MELDOLAS-BLUE; BIOSENSOR; METALLOPHTHALOCYANINES AB Nickel tetrasulfonated phthalocyanine (NiTsPc) immobilized onto titanized silica gel (ST) showed good stability and redox properties. The cyclic voltammograms obtained with a carbon paste electrode modified with ST-NiTsPc presented an enhanced peak current at 450 mV (vs. SCE) which did not shift with solution pH. The redox process was attributed to Ni-II/Ni-III, which presented a good electrocatalytical activity for oxidizing hydrazine in neutral solution. The process is controlled by the electron transfer step and no diffusion limitation was observed. The modified electrode was very sensitive for hydrazine, giving a detection limit of 1.0 x 10(-5) mol L-1, for an applied potential of 450 mV (vs. SCE). A linear response range was observed between 1.0 x 10(-4) and 6.0 x 10(-4) mol L-1, fit by the equation I = -0.1 (+/-0.1) + 7.9(+/-0.3) [Hydrazine], with a correlation coefficient of 0.998 for n = 6. The repeatability for 11 measurements was excellent, with a relative standard deviation of 3.7 %. The active material, nickel tetrasulfonated phthalocyanine modified silica, was stable for at least 6 months, losing only 10% of its signal over this period. C1 UNICAMP, Inst Chem, BR-13083970 Campinas, SP, Brazil. UFMA, Dept Chem, Sao luis, MA, Brazil. RP Kubota, LT, UNICAMP, Inst Chem, POB 6154, BR-13083970 Campinas, SP, Brazil. NR 39 TC 29 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 1040-0397 J9 ELECTROANAL JI Electroanalysis PD FEB PY 1998 VL 10 IS 2 BP 111 EP 115 PG 5 SC Chemistry, Analytical; Electrochemistry GA ZF315 UT ISI:000072885200008 ER PT J AU Hayashi, H TI Hydrazine synthesis: Commercial routes, catalysis and intermediates SO RESEARCH ON CHEMICAL INTERMEDIATES LA English DT Article ID HYDROGEN-PEROXIDE; TITANIUM SILICALITE; SELECTIVE OXIDATION; AMMOXIMATION; AMMONIA; CYCLOHEXANONE; AZINE C1 Univ Tokushima, Dept Chem Sci & Technol, Tokushima 770, Japan. RP Hayashi, H, Univ Tokushima, Dept Chem Sci & Technol, Tokushima 770, Japan. NR 38 TC 2 PU VSP BV PI ZEIST PA PO BOX 346, 3700 AH ZEIST, NETHERLANDS SN 0922-6168 J9 RES CHEM INTERMEDIATES JI Res. Chem. Intermed. PY 1998 VL 24 IS 2 BP 183 EP 196 PG 14 SC Chemistry, Multidisciplinary GA ZE632 UT ISI:000072814000009 ER PT J AU Jeevanandam, S Raja, VS Bhatgadde, LG TI Development and study of nickel aluminide coatings on titanium SO TRANSACTIONS OF THE METAL FINISHERS ASSOCIATION OF INDIA LA English DT Article AB Nickel aluminide as well as boron containing nickel aluminide coatings were deposited on pure titanium through electroless deposition of pure Ni and Ni-B followed by physical vapour deposition of aluminium and a subsequent heat treatment at 600 degrees C for 5 hr. and 10 hr. The coating thicknesses were studied as a function of concentration elf reducing agents, viz. hydrazine and potassium borohydride, bath pH and plating time. Variation of boron content with pH was also studied, The coating composition wets analysed by ICP-AES technique. X-ray diffraction data confirm the formation of aluminides viz.. AlNi3, AlNi2Ti and AlNi. Phase changes with respect to time of heat treatment were also studied. Aluminide coatings were further characterised by electrochemical measurements. In case of nickel aluminide coatings, polarisation resistance(Rp) increases with time of heat treatment, while for Ni-B-aluminide it decreases with time of heat treatment, AC impendence studies also support these findings. The decrease in Rp and increase in I-corr for Ni-B aluminide coating with increase in time of heat treatment might be due to diffusion of B out of Al coating and the increase information of Ni3B as evidenced by increase in height of XRD pattern. C1 INDIAN INST TECHNOL,DEPT MET ENGN & MAT SCI,MUMBAI 400076,INDIA. INDIAN INST TECHNOL,ADV CTR RES ELECT,MUMBAI 400076,INDIA. NR 7 TC 1 PU METAL FINISHERS ASSOC INDIA PI BOMBAY PA 4 SATGURU INDL ESTATE, VISHWESHWAR NAGAR ROAD, OFF AAREY ROAD, GOREGAON EAST, BOMBAY 400 063, INDIA SN 0971-5304 J9 TRANS MET FINISH ASSOC INDIA JI Trans. Met. Finish. Assoc. India PD JUL-SEP PY 1997 VL 6 IS 3 BP 181 EP 186 PG 6 SC Metallurgy & Metallurgical Engineering GA YE862 UT ISI:A1997YE86200002 ER PT J AU Lee, SJ Kim, TY Choi, KS Park, MK Han, BH TI Activated zirconium metal powder prepared by reduction of zirconium(IV) chloride with lithium promoted coupling of aldehydes, ketones and organic halides SO BULLETIN OF THE KOREAN CHEMICAL SOCIETY LA English DT Article ID HYDRAZINE MONOHYDRATE; CARBONYL-COMPOUNDS; NICKEL; NITROARENES; ZINC; TUNGSTEN; REAGENTS; PINACOLS; TITANIUM; URANIUM RP Lee, SJ, CHUNGNAM NATL UNIV,DEPT CHEM,COLL NAT SCI,TAEJON 305764,SOUTH KOREA. NR 30 TC 3 PU KOREAN CHEMICAL SOC PI SEOUL PA 635-4 YEOGSAM-DONG, KANGNAM-GU, SEOUL 135-703, SOUTH KOREA SN 0253-2964 J9 BULL KOR CHEM SOC JI Bull. Korean Chem. Soc. PD FEB 20 PY 1997 VL 18 IS 2 BP 224 EP 226 PG 3 SC Chemistry, Multidisciplinary GA WM671 UT ISI:A1997WM67100026 ER PT J AU Wang, C McKelvy, M Glaunsinger, W TI Early events in intercalation reactions: The preintercalation state SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID TITANIUM DISULFIDE; TUNNELING SPECTROSCOPY; METAL; COMPLEXES; GRAPHITE; CATALYSTS; TRANSPORT; TI1+XS2; TISE2 AB Ultrahigh vacuum scanning tunneling spectroscopy (UHV-STS) is used to make the first in situ measurements of reactant charge transfer with the host basal planes during the early events in lamellar intercalation processes to clarify the role and importance of charge transfer in intercalation reactivity. The level of basal-plane charge transfer is determined from the Fermi level shift relative to the host (TiS2) conduction-band edge. Prior to intercalation, the model reaction of ammonia with lamellar TiS2 exhibits low-level, pressure-independent adsorbate (ammonia) charge transfer to the basal planes, identifying a preintercalation state in which adsorbate charge transfer plays a key role in intercalation reactivity. Such a state can explain the anomalously-high reactivity exhibited by other molecular intercalation systems, such as hydrazine/TiSe2, where available evidence suggests strong preintercalation adsorbate-host charge transfer. Once intercalation occurs, ammonium forms and cointercalates with ammonia via the bulk redox rearrangement intercalation process, with substantial additional basal-plane charge transfer. Such behavior suggests that pre- and postintercalation charge transfer mechanisms can differ fundamentally for the same molecular reactants. UHV-STS has been shown to be a powerful technique for determining the level of basal-plane charge transfer throughout the intercalation process. C1 ARIZONA STATE UNIV,CTR SOLID STATE SCI,TEMPE,AZ 85287. ARIZONA STATE UNIV,DEPT CHEM & BIOCHEM,TEMPE,AZ 85287. NR 32 TC 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM JI J. Phys. Chem. PD DEC 12 PY 1996 VL 100 IS 50 BP 19218 EP 19222 PG 5 SC Chemistry, Physical GA VX875 UT ISI:A1996VX87500003 ER PT J AU Nordmann, F Fiquet, JM TI Selection criteria for the best secondary water chemistry SO NUCLEAR ENGINEERING AND DESIGN LA English DT Article AB This paper describes, for PWR plants, the approach for selecting the best chemistry-pH, amine, corrosion inhibitors-according to the secondary system characteristics, such as presence or not of copper alloys, steam generator tubing alloy, tube support plate design, sludge pile importance. The impact of condensate polisher, sludge lancing, chemical cleaning, as well as other ways of eliminating undesirable compounds or mitigating them are also discussed. For plants with simultaneous presence of carbon steel and copper alloys, alternate amines like morpholine, or new reagents such as ethanolamine (ETA), can be selected to manage erosion-corrosion of carbon steel and decrease corrosion transport, at a pH acceptable for copper alloys (9.2 at 25 degrees C). In more recent units, with an all ferrous system, a high pH operation, with only hydrazine addition, the easiest way, or with combined hydrazine and morpholine or ETA will be of some benefit against steam generator corrosion. When Alloy 600 has been selected, inhibitors such as boric acid, or maybe titanium oxide or cerium in the future, needs to be added in steam generators in order to decrease intergranular corrosion progression. In addition, caustic and lead contaminations must be strictly avoided, while sludge and deposits will be eliminated by lancing and chemical cleaning, if necessary. RP Nordmann, F, EDF,GRP LAB,21 ALLEE PRIVEE,F-93206 ST DENIS,FRANCE. NR 14 TC 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0029-5493 J9 NUCL ENG DES JI Nucl. Eng. Des. PD FEB PY 1996 VL 160 IS 1-2 BP 193 EP 201 PG 9 SC Nuclear Science & Technology GA TZ590 UT ISI:A1996TZ59000015 ER PT J AU TRUONG, CM CHEN, PJ CORNEILLE, JS OH, WS GOODMAN, DW TI LOW-PRESSURE DEPOSITION OF TIN THIN-FILMS FROM A TETRAKIS(DIMETHYLAMIDO)TITANIUM PRECURSOR SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID CHEMICAL-VAPOR-DEPOSITION; HYDRAZINE; ADSORPTION; TITANIUM; AMMONIA; GROWTH; COADSORPTION; SURFACE AB We demonstrate that, at low reagent pressures (<10(-4) Torr), the prevalent TiN film deposition mechanism operates exclusively on the reactions between tetrakis(dimethylamido)titanium (TDMAT) and NH3 at the growth surface. Our surface spectroscopic analyses indicate that film deposition in the low-pressure regime is also capable of delivering TiN with very low residual carbon levels. Spectroscopic evidence supporting this surface-reaction pathway. to TiN films is presented in this report. The kinetics of the reactions between TDMAT and NH3 on TiN surfaces are also explored. In addition, we also discuss a proposed mechanistic framework for this low-pressure deposition process. C1 TEXAS A&M UNIV,DEPT CHEM,COLLEGE STN,TX 77843. NR 26 TC 26 PU AMER CHEMICAL SOC PI WASHINGTON PA PO BOX 57136, WASHINGTON, DC 20037-0136 SN 0022-3654 J9 J PHYS CHEM JI J. Phys. Chem. PD MAY 25 PY 1995 VL 99 IS 21 BP 8831 EP 8842 PG 12 SC Chemistry, Physical GA RA147 UT ISI:A1995RA14700059 ER PT J AU KUBATA, LT GUSHIKEM, Y PEREZ, J TANAKA, AA TI ELECTROCHEMICAL PROPERTIES OF IRON PHTHALOCYANINE IMMOBILIZED ON TITANIUM(IV) OXIDE-COATED ON SILICA-GEL SURFACE SO LANGMUIR LA English DT Article ID CUPRIC HEXACYANOFERRATE; HYDRAZINE; GRAPHITE; ELECTROOXIDATION; ELECTRODES; REDUCTION; OXYGEN; MN; NI; CU AB Electrochemical studies of iron tetrasulfonated phthalocyanine (FeTsPc)immobilized on silica gel modified with titanium(IV) oxide were carried out in aqueous solutions. Cyclic voltammograms recorded in different supporting electrolyte solutions presented a redox process that became better defined under acidification. The position of the peak potentials (0.35-0.45 V vs SCE) and their invariance with solution pH indicated that these processes can be assigned to the Fe(II)TsPc/Fe(III)TsPc redox couple, with characteristics similar to those observed for FeTsPc adsorbed on graphite surfaces. The nature of the supporting cation in solution does not shift the midpoint potential (E(m)) of the redox process, when Li+, Na+, K+, and NH4+ are used. In contrast, the supporting anion has a strong effect, i.e., the E(m) shifts toward more positive values in the order ClO4->NO3->Cl->SO4=. Preliminary experiments indicated that the modified electrode presents catalytic activity for hydrazine oxidation in neutral solution. C1 UNIV CAMPINAS,INST QUIM,BR-13083970 CAMPINAS,SP,BRAZIL. UNIV SAO PAULO,INST FIS & QUIM SAO CARLOS,BR-13560970 SAO CARLOS,SP,BRAZIL. NR 28 TC 0 PU AMER CHEMICAL SOC PI WASHINGTON PA PO BOX 57136, WASHINGTON, DC 20037-0136 SN 0743-7463 J9 LANGMUIR JI Langmuir PD MAR PY 1995 VL 11 IS 3 BP 1009 EP 1013 PG 5 SC Chemistry, Physical GA QP595 UT ISI:A1995QP59500052 ER PT J AU VOGT, KW NAUGHER, LA KOHL, PA TI LOW-TEMPERATURE NITRIDATION OF TRANSITION-METALS WITH HYDRAZINE SO THIN SOLID FILMS LA English DT Article DE NITRIDES; SILICON NITRIDE; TITANIUM NITRIDE; X-RAY PHOTOELECTRON SPECTROSCOPY ID RAY PHOTOELECTRON-SPECTROSCOPY; TITANIUM NITRIDE; SILICON-NITRIDE; THIN-FILMS; DECOMPOSITION; N2H4; CO; ADSORPTION; SURFACE; GROWTH AB Transition metal nitride films have been formed by low temperature (400 degrees C) nitridation with hydrazine. The process uses low temperature cracking of hydrazine to form nitrogen radicals that react with the substrates to form nitride films. Auger electron spectroscopy and X-ray photoelectron spectroscopy were used for chemical analysis of the films. The results show that nitride films with an oxide impurity were made with Co, Cr, Fe, Mo, Si, Ta, Ti, V, and W. The most likely sources of oxygen contamination were incomplete oxide removal during pre-cleaning, water impurities in the hydrazine, and oxygen and water contamination of the films after completion of the nitridation process. Experiments with oxidized tantalum, iron, aluminum, and silicon show the effects of oxides on the hydrazine nitridation reaction. Preliminary electrochemical corrosion tests demonstrate the corrosion protection of iron provided by the iron nitride film. C1 GEORGIA INST TECHNOL,SCH CHEM ENGN,ATLANTA,GA 30332. NR 48 TC 9 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD FEB 1 PY 1995 VL 256 IS 1-2 BP 106 EP 115 PG 10 SC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter GA QF102 UT ISI:A1995QF10200019 ER PT J AU KIM, KW KIM, JD AOYAGI, H YOSHIDA, Z TI KINETICS OF REDUCTION OF URANIUM(VI) TO URANIUM(IV) AT TITANIUM ELECTRODE IN NITRIC-ACID AND HYDRAZINE MEDIA SO JOURNAL OF NUCLEAR SCIENCE AND TECHNOLOGY LA English DT Article DE URANIUM; URANIUM IONS; REDUCTION; TITANIUM ELECTRODE; NITRIC ACID; HYDRAZINE; ELECTRODE REACTION KINETICS; VOLTAMMETRY; ELECTROLYTIC PREPARATION; CONTROLLED-POTENTIAL ELECTROLYSIS; CONCENTRATION DEPENDENCE AB The kinetic study of the reduction of U(VI) at the titanium electrode in nitric acid and hydrazine media was carried out at 25+/-0.5-degrees-C. Uranium (VI) is reduced through a totally irreversible process and kinetic parameters are affected by both the concentration of nitric acid and the electrolytic potential. An empirical equation to express the rate of the reduction of U(VI) was proposed and was confirmed to be in fairly good agreement with the amount of U(IV) produced by the controlled-potential electrolysis. The optimal condition for the preparation of U(IV) from U(VI) was found to be the electrolysis at -0.5V vs. Ag-AgCl/sat. KCl in 1 approximately 2 M HNO3 and 0.1 approximately 0.2 M hydrazine. C1 KOREA ADV INST SCI & TECHNOL,DEPT CHEM ENGN,TAEJON,SOUTH KOREA. JAPAN ATOM ENERGY RES INST,ADV SCI RES CTR,TOKAI,IBARAKI 31911,JAPAN. RP KIM, KW, KOREA ATOM ENERGY RES INST,DEPT PROJECT MANAGEMENT,TAEJON,SOUTH KOREA. NR 18 TC 5 PU ATOMIC ENERGY SOC JAPAN PI TOKYO PA 1-1-13 SHIMBASHI MINATO-KU, TOKYO 105, JAPAN SN 0022-3131 J9 J NUCL SCI TECHNOL JI J. Nucl. Sci. Technol. PD APR PY 1994 VL 31 IS 4 BP 329 EP 334 PG 6 SC Nuclear Science & Technology GA NN800 UT ISI:A1994NN80000010 ER PT J AU KATTI, KV GE, YW SINGH, PR DATE, SV BARNES, CL TI TRANSITION-METAL CHEMISTRY OF MAIN-GROUP HYDRAZIDES .4. PHOSPHORUS HYDRAZIDO FERROCENES AS NOVEL SYNTHONS TO NEW IRON(II)-PALLADIUM(II) HETEROTRIMETALLIC ORGANOMETALLIC COMPOUNDS - SYNTHESIS AND CHARACTERIZATION OF PALLADIUM(II) CHLORIDE COMPLEXES OF FERROCENE FUNCTIONALIZED PHOSPHORUS HYDRAZIDES - SINGLE-CRYSTAL X-RAY STRUCTURES OF C2H5OP(S)(NCH3NCHCP'FECP)2 AND C2H5OP(S)(NCH3NCHCP'FECP)2.PDCL2 [CP'=C5H4, CP=C5H5] SO ORGANOMETALLICS LA English DT Article ID HETEROBIMETALLIC COMPLEXES; OXIDATIVE ADDITION; SATURATED-HYDROCARBONS; DATIVE BOND; TITANIUM; ACTIVATION; PHOSPHINE; METHANE; LIGANDS; PLATINUM AB The reactions of aryl-, alkyl-, and alkoxy-substituted phosphorus hydrazides, RP(E)(NMeNH2)2 (R = Ph, E = S, 1; R = OEt, E = S, 2; R = Ph, E = O, 3; R = Et, E = O, 4; R = Me, E = O, 5) with ferrocenecarboxaldehyde gave metallocene-functionalized phosphorus hydrazides in good yields (approximately 90-95%) as air-stable crystalline solids with the following chemical compositions: RP(E)(NMeNCHCp'FeCP)2 (R = Ph, E = S, 6; R = OEt, E = S, 7; R = Ph, E = O, 8; R = Et, E = O, 9; R = Me, E = O, 10). These ferrocenyl phosphorus hydrazides 6-10 can be used as versatile synthons to produce new heterometallic organometallic compounds. For example, 6-10 react with PdCl2(PhCN)2 at 25-degrees-C to give Fe(II)-Pd(II) trimetallic compounds RP(E)(NMeNCHCp'FeCp)2-PdCl2 (R = Ph, E = S, 11; R = OEt, E = S, 12; R = Ph, E = O, 13; R = Et, E = O, 14; R = Me, E = O, 15) in good yields. The chemical constitutions of 6-10 and 11-15 were established by complete NMR (H-1 and P-31) spectroscopic and C, H, and N analysis. As representative examples, X-ray structures of 7 and 12 have been determined. Crystal data for C2H5OP(S)(NMeNCHCp'FeCP)2, 7: orthorhombic, space group P2(1)2(1)2(1), a = 7.5556(11) angstrom, b = 10.7652(12) angstrom, c = 33.186(4) angstrom, V = 2699.3(3) angstrom3, Z = 4. The structure was solved by direct methods and was refined to R = 0.038. The structure of 12 comprises the neutral monomeric trimetallic complex C2H5OP(S) (NMeNCHCp'FeCP)2.PdCl2 with the Pd(II) center in a square planar geometry. The structure of 12 is characterized by a six-membered ring with the Pd(II) bonded to two terminal hydrazine units of 7 in a cis disposition. Crystal data of 12: monoclinic, space group P2(1)/c, a = 15.731(3) angstrom, b = 18.695(3) angstrom, c = 11.918(2) angstrom, beta = 98.180(7)degrees, V = 3469.3(10) angstrom3, Z = 4. The structure was solved by direct methods and was refined to R = 0.033. C1 UNIV MISSOURI,DEPT CHEM,RES REACTOR,COLUMBIA,MO 65211. RP KATTI, KV, UNIV MISSOURI,CTR RADIOL RES,COLUMBIA,MO 65211. NR 45 TC 27 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0276-7333 J9 ORGANOMETALLICS JI Organometallics PD FEB PY 1994 VL 13 IS 2 BP 541 EP 547 PG 7 SC Chemistry, Inorganic & Nuclear; Chemistry, Organic GA MX338 UT ISI:A1994MX33800027 ER PT J AU KIM, KW KIM, JD AOYAGI, H TOIDA, Y YOSHIDA, Z TI PRETREATMENT OF A TITANIUM ELECTRODE FOR REDUCTION OF URANIUM(VI) IN NITRIC ACID-HYDRAZINE MEDIA SO JOURNAL OF NUCLEAR SCIENCE AND TECHNOLOGY LA English DT Article DE TITANIUM ELECTRODES; TITANIUM OXIDES; VOLTAMMETRY; PRETREATMENT; HYDRAZINE; URANIUM; NITRIC ACID; EPMA; MIXTURE; REDUCTION; ELECTROLYSIS AB The oxide film at the surface of a titanium electrode, which was observed by an Electron Probe Microanalyzer (EPMA) measurement, was found to hinder an electrolytic reduction of U(VI) to U(IV) in a nitric acid solution containing hydrazine. A method for the pretreatment of the titanium electrode to obtain a clear voltammogram for the reduction of U(VI) was investigated, and it was found that a controlled-potential electrolysis with a potential less than -0.8 V vs. SSE for about 30 min was adequate to remove the oxide film. The effect of the composition of the HNO3+N2H5+ solution on the degree of pretreatment was examined. Voltammograms for the reduction of U(VI) at the oxide-free titanium electrode were recorded and analyzed. C1 JAPAN ATOM ENERGY RES INST,ADV SCI RES CTR,TOKAI,IBARAKI 31911,JAPAN. RP KIM, KW, KOREA ATOM ENERGY RES INST,DEPT PROJECT MANAGEMENT,RES FACIL DESIGN LAB,POB 7,TAEJEON,JAPAN. NR 12 TC 2 PU ATOMIC ENERGY SOC JAPAN PI TOKYO PA 1-1-13 SHIMBASHI MINATO-KU, TOKYO 105, JAPAN SN 0022-3131 J9 J NUCL SCI TECHNOL JI J. Nucl. Sci. Technol. PD JUN PY 1993 VL 30 IS 6 BP 554 EP 559 PG 6 SC Nuclear Science & Technology GA LP648 UT ISI:A1993LP64800009 ER PT J AU CUNNINGHAM, J HICKEY, JN BROWN, NMD MEENAN, BJ TI CATALYTIC AND PHYSICOCHEMICAL CHARACTERIZATIONS OF NOVEL OXIDE-SUPPORTED COPPER-CATALYSTS .1. HYDROSOL-PREPARED CU/TIO2 AND EFFECTS OF PREREDUCTION ON HYDROGENATION AND OLIGOMERIZATION OF ACETONE SO JOURNAL OF MATERIALS CHEMISTRY LA English DT Article DE COPPER; CATALYTIC MATERIAL; OXIDE SUPPORT; HYDROGENATION; OLIGOMERIZATION ID METAL-SUPPORT; METHANOL SYNTHESIS; ALDOL CONDENSATION; MAGNESIUM-OXIDE; AUGER-SPECTRA; CO; SPECTROSCOPY; ADSORPTION; KINETICS AB Catalytic conversions of acetone, allied to transmission electron microscopy (TEM), electron spectroscopy for chemical applications (ESCA) and temperature-programmed desorption (TPD) techniques have been used to characterize titanium-dioxide-supported copper preformed by the reduction of aqueous copper malonate with hydrazine. Scanning electron microscopy (SEM) and TEM showed aggregates of 30 +/- 10 nm TiO2 particles edged by smaller copper particles (ca. 10 nm). The coexistence of copper and TiO2 in such aggregates was confirmed by energy dispersive X-ray analysis (EDXA). Comparisons of the X-ray photoelectron spectroscopy (XPS) Cu 2p3/2 and X-ray excited Auger electron spectroscopy (XAES) Cu L3M4,5M4,5 features of the 'as-stored' materials with those after in situ reduction at 453, 503 and 548 K, confirmed that Cu2+ was converted to Cu+ after reduction at 503 K. Significant amounts of Cu+ were also present after reduction at 503 K, but little or no Cu0. At 423 K