Hybrid organic-inorganic compounds, obtained by the sol-gel method from organoalcoxysilanes and metal complexes

The paper summarizes information on a narrow class of polycondensed systems known as organic-inorganic hybrid materials, in which particles of metal complexes are embedded in a silicon oxide matrix. There are only one type of particles: coordination compounds of cobalt, chromium, neodymium, erbium, and ytterbium. These materials are prepared by a sol-gel process from molecular precursors that undergo inorganic polymerization called hydrolytic polycondensation. Basic information about the sol-gel processes is presented. The types and properties of the most common sol-gel monomers and oligomers, as well as the methods of obtaining metal-containing gels, are considered, a general idea of the sol-gel processes is described, and the fields of application of the obtained materials are listed. Syntheses of siloxane, carbonate, and carbonate-siloxane cobaltcarbonyl gels are based on the reaction of homomolecular disproportionation of dicobalt octacarbonyl under the action of 3-aminopropyltriethoxysilane, pyridine, and dimethylformamide. A number of organosilicon amine gels have been obtained from 3-aminopropyltriethoxysilane, cobalt(II), chromium(III) chlorides, and triethoxysilane. The sol-gel films containing cobalt, chromium, and neodymium have been obtained from organosilicon amine complexes, their electronic absorption spectra have been measured and interpreted, their transformations during the absorption of oxygen and hydrogen chloride have been shown, and nonlinear optical properties have been measured. Organosilicon amidophosphates are synthesized by the interaction of 3-aminopropyltriethoxysilane with bis (dimethylamido)chlorophosphate and diphenylchlorophosphate. On their basis, complexes of erbium and ytterbium have been obtained, and their absorption and emission spectra have been recorded. Two examples of immobilization of metal complexes on the surface of highly porous polysiloxane hydride and lepidoid siloxene are given.