Preparation of oxide materials from metal alkoxides

A Versatile and Low‐Toxicity Route for the Production of Electroceramic Oxide Nanopowders

“…15 2 O, was determined by weighing the resulting mass of oxide obtained from the calcination of a known amount of precursor at 900°C for 8 h. The organic species used were citric acid (Aldrich, 99 %), acrylic acid (Aldrich, anhydrous, 99 %), N,NЈ-methylene bis(acrylamide) (Aldrich, 99 %) and hydrogen peroxide (Aldrich, 30 % w/w in water). The synthesis process is as follows: Cation precursors are dissolved separately in deionised water (80-100 mL) in the proportion corre-sponding to the final product.…”

“…Sol-gel chemistry is a remarkably versatile approach for the fabrication of ceramic powders at low temperatures. [2] Nevertheless, in most of cases, the application of a sol-gel route involves a high complexity due to the necessity of a fine adjustment of parameters. [3] The Pechini method is more versatile, because the technique has a strong robustness and requires less or null adaptation from one material to the other.…”

Rhenium alkoxides

“…22,27 This method was used to prepare the following compounds: Re 4 O 6 (OMe) 12 , Re 4 O 2 (OMe) 16 , Re 4 O 6-y (OMe) 12+y , Re 4 O 6 (OPr i ) 10 , ReMoO 2 (OMe) 7 , Re 4-x Mo x O 6-y (OMe) 12+y , and Re 4-x W x O 6-y (OMe) 12+y . 22,27 This method was used to prepare the following compounds: Re 4 O 6 (OMe) 12 , Re 4 O 2 (OMe) 16 , Re 4 O 6-y (OMe) 12+y , Re 4 O 6 (OPr i ) 10 , ReMoO 2 (OMe) 7 , Re 4-x Mo x O 6-y (OMe) 12+y , and Re 4-x W x O 6-y (OMe) 12+y .…”

“…38 In the W 4 (OEt) 16 molecule with eight electrons, the elon gated side of the rhombus is 2.936(2) Å, the shorter side is 2.646(2) Å, and the diagonal is 2.763(1) Å. The length of the single σ bond can be estimated from the sum of the 6 2.559(1) 1 17 ReMoO 2 (OMe) 7 2.658(2) 1 27 Re 4 O 6 (OPr i ) 10 2.5204(7)-2.5501(5) >1 23, 24, 26 Re 2 (OMe) 10 2.5319(7) 2 15 Re 3 (OPr i ) 9 2.36 2 12, 13 Re 3 (OCH 2 Bu t ) 9 2.365(1)-2.372(1) 2 14 41 (5) Oxo and alkoxo ligands serve as effective π do nors; this results in an increase in the M=O and M-O(R) bond order in the case of terminal ligands.…”

Technological aspects of preparation of high-purity compounds for sol-gel and pyrolytic synthesis methods

“…These compounds can serve for the production of both ultrafine powders and ultrathin protective or functional coatings and fibers. The alkoxide variant of the sol-gel and vapor-phase technologies allows one to fabricate complex oxide systems, in particular, magnesium orthosilicate (forsterite), mullite, and other compounds doped with different activators for application in laser engineering [1][2][3], as well as related composite materials in glass and polymer matrices. These powders and thinlayer materials can find applications for growth of single crystals, manufacturing of transparent ceramic materials and optical fibers, and preparation of highly effective catalysts and sorbents.…”