Metal oxide trialkylsilyloxide polymers. Part V. Further studies on titanium oxide triethylsilyloxide polymers

1969 ◽  
Vol 47 (22) ◽  
pp. 4113-4116 ◽  
Author(s):  
D. C. Bradley ◽  
J. W. Lorimer ◽  
C. Prevedorou-Demas
Keyword(s):  
Metal Oxide ◽  
Titanium Oxide ◽  
Linear Dependence ◽  
High Vacuum ◽  
Molecular Weights ◽  
Controlled Conditions

Tetrakis(triethylsilyloxy)titanium, Ti(OSiEt3)4, was hydrolyzed under controlled conditions in dioxane at 60 °C. The soluble initial products [TiOx(OSiEt3)4−2x]n, with x = 0.1–0.5, underwent disproportionation when heated at 65 °C under high vacuum to give Ti(OSiEt3)4 and products with values of x in the range 0.4–1.4. Molecular weights were determined by cryoscopy in cyclohexane, and the linear dependence of 1/n on x was used as a basis for structural proposals. The results are compared with those obtained previously for the initial products of hydrolysis.

Metal Oxide Trialkylsilyloxide Polymers. Part VI. Aluminum Oxide Trimethylsilyloxides

1971 ◽  
Vol 49 (13) ◽  
pp. 2310-2314 ◽  
Author(s):  
D. C. Bradley ◽  
J. W. Lorimer ◽  
C. Prevedorou-Demas
Keyword(s):  
Metal Oxide ◽  
Aluminum Oxide ◽  
Linear Dependence ◽  
Degree Of Polymerization ◽  
Oh Groups ◽  
Molecular Weights ◽  
Controlled Conditions ◽  
Adjacent Unit ◽  
Oxygen Atoms

Tris(trimethylsilyloxy)aluminum, [Al(OSiMe3)3]2, was hydrolyzed under controlled conditions in dioxane at 25 °C. The soluble initial products [AlOx(OH)z(OSiMe3)3−2x−z]n, with x = 0.03–0.65, underwent disproportionation when heated at 120–150 °C under vacuum to give final products with x = 0.8–1.1. Molecular weights were determined by cryoscopy in cyclohexane, and the linear dependence of 1/n on x was combined with an extension of the theory of regular polymer series to show that the number of OH groups, z, was small compared to the number of bridging oxygen atoms, x, per Al atom. The initial products consist of dimeric units, each linked to an adjacent unit by one or two oxygen bridges between aluminum atoms. The degree of polymerization is 1 to 4, based on the dimer unit. The final products have much higher degrees of polymerization (10–40, based on the dimer), and appear to contain a higher proportion of Al—O—Al bridges.

METAL OXIDE TRIALKYLSILYLOXIDE POLYMERS (POLYTRIALKYLSILOXANOMETALLOXANES): PART I. TITANIUM OXIDE TRIMETHYLSILYLOXIDE POLYMERS

1963 ◽  
Vol 41 (3) ◽  
pp. 629-635 ◽  
Author(s):  
D. C. Bradley ◽  
C. Prevedorou-Demas
Keyword(s):  
Molecular Weight ◽  
Metal Oxide ◽  
Titanium Oxide ◽  
Degree Of Polymerization ◽  
Average Degree ◽  
Degree Of Hydrolysis ◽  
Controlled Conditions

Tetrakis-(trimethylsilyloxy)-titanium Ti(OSiMe3)4 has been hydrolyzed under controlled conditions in dioxane. The initial products of hydrolysis undergo facile disproportionation, e.g. 3Ti2O(OSiMe3)6 → 4Ti(OSiMe3)4 + polymeric Ti2O3(OSiMe3)2. Molecular weight determinations were made on the titanium oxide trimethylsilyloxide polymers (polytrimethylsiloxanotitanoxanes) obtained by thermal disproportionation. Structures have been suggested for the polymers on the basis of the variation of number-average degree of polymerization with the degree of hydrolysis.

Ultra-high vacuum chemical vapor deposition and in situ characterization of titanium oxide thin films

1991 ◽  
Vol 6 (9) ◽  
pp. 1913-1918 ◽  
Author(s):  
Jiong-Ping Lu ◽  
Rishi Raj
Keyword(s):  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Titanium Oxide ◽  
Vapor Deposition ◽  
Photoelectron Spectroscopy ◽  
High Vacuum ◽  
Chemical Vapor ◽  
Titanium Isopropoxide ◽  
Ultra High Vacuum

Chemical vapor deposition (CVD) of titanium oxide films has been performed for the first time under ultra-high vacuum (UHV) conditions. The films were deposited through the pyrolysis reaction of titanium isopropoxide, Ti(OPri)4, and in situ characterized by x-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES). A small amount of C incorporation was observed during the initial stages of deposition, through the interaction of precursor molecules with the bare Si substrate. Subsequent deposition produces pure and stoichiometric TiO2 films. Si–O bond formation was detected in the film-substrate interface. Deposition rate was found to increase with the substrate temperature. Ultra-high vacuum chemical vapor deposition (UHV-CVD) is especially useful to study the initial stages of the CVD processes, to prepare ultra-thin films, and to investigate the composition of deposited films without the interference from ambient impurities.

Cleavage of models for RNA mediated by a diZn(II) complex of bis[1,4-N1,N1′(1,5,9-triazacyclododecanyl)]butane in methanol and ethanol

2009 ◽  
Vol 87 (5) ◽  
pp. 640-649 ◽  
Author(s):  
C. Tony Liu ◽  
Stephanie A. Melnychuk ◽  
Chaomin Liu ◽  
Alexei A. Neverov ◽  
R. Stan Brown
Keyword(s):  
Transition State ◽  
Linear Dependence ◽  
Catalyst Concentration ◽  
Active Form ◽  
Catalytic Efficiency ◽  
Saturation Binding ◽  
Controlled Conditions ◽  
Versus Complex ◽  
Leaving Groups ◽  
Ph Controlled

The cleavage of seven RNA model 2-hydroxypropyl aryl phosphates (1) catalyzed by a dinuclear Zn(II) complex of bis[1,4-N1,N1′(1,5,9-triazacyclododecanyl)]butane (4) was studied in methanol and ethanol at 25 °C under pH controlled conditions. The results are compared with what was reported earlier for the dinuclear Zn(II) complex of the lower homologue bis[1,3-N1,N1′(1,5,9-triazacyclododecanyl)]propane (3). In methanol, the higher homologue exhibits saturation binding with substrates having poor aryloxy leaving groups. With good leaving groups there is an observed linear dependence of kobs versus complex concentration without saturation binding over the catalyst concentration range investigated. In ethanol, strong saturation binding between the active form of the catalyst ((RO–):Zn(II)2:4) and all substrates is observed, the results observed in both solvents being similar to what was reported for the lower (RO–):Zn(II)2:3 homologue. Energetics calculations are presented for the (RO–):Zn(II)2:4-catalyzed cleavage of each substrate in both solvents to assess the catalytic efficiency via the ΔΔG‡ for catalyst binding a transition state comprising [RO–:1]‡ or its kinetic equivalent.

scholarly journals The Roughness-Enhanced Light Emission from Metal-Oxide-Silicon Light-Emitting Diodes Using Very High Vacuum Prebake

2002 ◽  
Vol 41 (Part 2, No. 3B) ◽  
pp. L326-L328 ◽  
Author(s):  
Min-Hung Lee ◽  
Kuan-Fu Chen ◽  
Chang-Chi Lai ◽  
Chee Wee Liu ◽  
Woei-Wu Pai ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Light Emitting Diodes ◽  
Light Emission ◽  
High Vacuum ◽  
Light Emitting ◽  
Metal Oxide Silicon ◽  
Very High

Metal oxide electrocatalyst support for carbon-free durable electrodes with excellent corrosion resistance at high potential conditions

2021 ◽  
Author(s):  
Yuuki Sugawara ◽  
Takuya Hihara ◽  
Gopinathan M. Anilkumar ◽  
Keigo Kamata ◽  
Takeo Yamaguchi
Keyword(s):  
Corrosion Resistance ◽  
Metal Oxide ◽  
Titanium Oxide ◽  
Carbon Support ◽  
High Potential ◽  
Catalytic Reactions ◽  
Excellent Corrosion Resistance ◽  
Potential Conditions

Corrosion-resistive conductive titanium oxide exhibited remarkably higher durability than a carbon support during electrochemical catalytic reactions under high potential conditions.

Reduced Titanium Oxide as Carbon-Free Support of Non-Precious Metal Oxide-Based Cathodes for PEFCs

2016 ◽  
Vol 75 (14) ◽  
pp. 863-868 ◽  
Author(s):  
H. Igarashi ◽  
A. Ishihara ◽  
T. Nagai ◽  
S. Tominaka ◽  
K. Matsuzawa ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Titanium Oxide ◽  
Precious Metal
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