Alkoxides and alkylalkoxides of metals and metalloids

Mehrotra, R. C.

doi:10.1016/0073-8085(67)80023-8

Cited by 83 publications

(23 citation statements)

References 205 publications

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“…For our precursor, we chose lithium niobium isopropoxide (LiNb(OPr i ) 6 ), particularly for its preset metal stoichiometry and its lower thermal stability relative to more readily available straight-chain analogues. [14] A possible route for the decomposition of LiNb(OPr i ) 6 is initiated by removal of a g-hydrogen by an adjacent alkoxide ligand. [15] This decomposition produces gaseous alkenes and alcohols as by-products and oxide linkages between the metal centers of soluble monomers.…”

mentioning

confidence: 99%

Solution‐Phase Synthesis of Crystalline Lithium Niobate Nanostructures

Wood¹,

Mocanu²,

Gates³

2008

Advanced Materials

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mentioning

confidence: 99%

Solution‐Phase Synthesis of Crystalline Lithium Niobate Nanostructures

Wood¹,

Mocanu²,

Gates³

2008

Advanced Materials

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“…The mechanism of the hydrolytic polycondensation of titanium alkoxides, yielding powders of titanium dioxide or hydroxide in alcoholic or aqueous media, has been described in the literature [26,[29][30][31]. The reactions can be represented in a simplifi ed form by the following scheme: (1) step-by-step hydrolysis of titanium alkoxide Naturally, the real process is much more complicated and occurs by a multiple-path mechanism.…”

Section: Methodsmentioning

confidence: 99%

“…It should be noted that the mechanism of titanium alkoxides hydrolytic polycondensation has been studied in alcoholic media [15,26,27]. However, most of studies have been aimed to develop methods for obtaining only TiO 2 nanoparticles with a narrow size distribution by the sol-gel method in various media [15-17, 26, 28, 29].…”

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confidence: 99%

Effect of kinetic features in synthesis of hybrid copolymers based on Ti(OPri)4 and hydroxyethyl methacrylate on their structure and properties

et al. 2015

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Effect of synthesis conditions on the structure and optical properties of hybrid copolymers based on Ti(OPr i ) 4 and hydroxyethyl methacrylate was determined. Raising the concentration of the methacrylic monomer in the system leads to a longer hydrolytic polycondensation of titanium alkoxide and faster radical polymerization of the organic monomer. Copolymers containing poly(titanium oxide) with a nearly anatase structure were obtained in the conditions of a double-stage synthesis including successive stages of low-temperature hydrolytic polycondensation and polymerization. In the case of a single-stage synthesis at 70°C, which combines simultaneously occurring polycondensation and polymerization processes, the copolymer contains the anatase (75%) and rutile (25%) forms of poly(titanium oxide).In the last two decades, extensive studies have been carried out in order to obtain nanostructured organoinorganic materials because of their optimal combination of numerous useful functions that are inherent in each component and cannot be found simultaneously in any other material [1]. The most spectacular examples of hybrid materials are nanocomposites based on SiO 2 , TiO 2 , VO 2 , and ZrO 2 in polymeric media. These nanocomposites are used in various fi elds of modern technology: biomedicine and ecology [2-4] and manufacture of solar cell arrays [5][6][7], photo/electrochromic and membrane materials, sensors [8-10], and catalysts for various reactions used to remove contaminants from the environment [11][12][13][14].The following materials can be distinguished among those being presently developed: organo-inorganic materials based on TiO 2 dispersed in a polymeric matrix and gels of poly(titanium oxide) (-TiO-) n in organic media [15][16][17][18]. Materials of this kind posses unique optical properties because of being able to effectively absorb light in the UV spectral range, which results in charge separation at the Ti-O bond and leads to the following conversion: Ti 4+ + e ← → Ti 3+ [11][12][13][14]. This property largely determines the possibility of further application of the material. It should, however, be noted that (-TiO-) n gels with high charge-separation effi ciency [18][19][20] are unstable in the course of time because of the solvent evaporation and are form-unstable. When TiO 2 powders are dispersed in a polymeric matrix, it is diffi cult to provide a homogeneous distribution of its particles with the bulk of the material. In addition, the charge-separation effi ciency in dispersions is lower than that in gels because the a single-electron-transition reaction involves only atoms on the surface of a particle, and, moreover, coarse particles scatter UV light [21]. All these factors hinder the practical application of gels and polymeric composites of titanium dioxide. Therefore, a topical task is to develop solid materials based on poly(titanium oxide), which retains the charge-separation ability as in the form of gels.

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“…27 3. Using a clean, oven-dried cannula, transfer 120 ml of anhydrous n-heptane to the 250 ml RBF containing the metal alkoxide solution 3.…”

Section: Synthesis Of Silica-encapsulated Monometallic or Bimetallic mentioning

confidence: 99%

Reverse Microemulsion-mediated Synthesis of Monometallic and Bimetallic Early Transition Metal Carbide and Nitride Nanoparticles

Hunt

Román‐Leshkov

2015

JoVE

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A reverse microemulsion is used to encapsulate monometallic or bimetallic early transition metal oxide nanoparticles in microporous silica shells. The silica-encapsulated metal oxide nanoparticles are then carburized in a methane/hydrogen atmosphere at temperatures over 800 °C to form silica-encapsulated early transition metal carbide nanoparticles. During the carburization process, the silica shells prevent the sintering of adjacent carbide nanoparticles while also preventing the deposition of excess surface carbon. Alternatively, the silica-encapsulated metal oxide nanoparticles can be nitridized in an ammonia atmosphere at temperatures over 800 °C to form silica-encapsulated early transition metal nitride nanoparticles. By adjusting the reverse microemulsion parameters, the thickness of the silica shells, and the carburization/nitridation conditions, the transition metal carbide or nitride nanoparticles can be tuned to various sizes, compositions, and crystal phases. After carburization or nitridation, the silica shells are then removed using either a room-temperature aqueous ammonium bifluoride solution or a 0.1 to 0.5 M NaOH solution at 40-60 °C. While the silica shells are dissolving, a high surface area support, such as carbon black, can be added to these solutions to obtain supported early transition metal carbide or nitride nanoparticles. If no high surface area support is added, then the nanoparticles can be stored as a nanodispersion or centrifuged to obtain a nanopowder. Video LinkThe video component of this article can be found at

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Alkoxides and alkylalkoxides of metals and metalloids

Cited by 83 publications

References 205 publications

Solution‐Phase Synthesis of Crystalline Lithium Niobate Nanostructures

Solution‐Phase Synthesis of Crystalline Lithium Niobate Nanostructures

Effect of kinetic features in synthesis of hybrid copolymers based on Ti(OPri)4 and hydroxyethyl methacrylate on their structure and properties

Reverse Microemulsion-mediated Synthesis of Monometallic and Bimetallic Early Transition Metal Carbide and Nitride Nanoparticles

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