Cyclic tetrasiloxanetetraols: Formation, isolation, and characterization
Hydrolysis of trialkoxysilanes having various substituents gave cyclic tetrasiloxanetetraols with all-cis isomer as the major fraction in the presence of equimolar amounts of water and sodium hydroxide. All stereoisomers of phenyl derivative were produced
Synthetic application of silicates/silanolates and their hydrolyzed polysilanol siloxanes for polyhedral oligomeric silsesquioxanes (POSSs)
Several types of silicate and their hydrolyzed polysilanols were applied to the synthesis of polyhedral oligomeric silsesquioxanes (POSSs). Silicate cubic octasilicate [Si8O20]8? 5 was silylated with trimethylchlorosilane to yield the incompletely trimethylsilylated cubic octasilicate [Si8O20](SiMe3)7H 1b bearing one silanol in addition to the totally trimethylsilylated derivative [Si8O20](SiMe3)8 1a. Further silylation of the monosilanol 1b with dimethylchlorosilane and α,ω-hydridochlorooctamethyltetrasiloxane resulted in the formation of POSSs 1c,d, which have hydrosilyl groups as elongated siloxane side chain. Attempts to generate an amino-substituted POSS via chloromethyldimethylsilylation of silicate 5 followed by reaction with amine as well as lithium amide failed. Amino-substitution was accomplished via the use of amine as a catalyst for the capping reaction of incompletely condensed trisilanol 10b with γ-aminopropyltrimethoxysilane affording mono amino-functionalized POSSs 2b,c in moderate yields. Another group of silanolates 7-9 was hydrolyzed with AcOH or HCl to give the corresponding cyclic polysilanol siloxanes 11a-c, respectively. Amine-catalyzed condensation of several of these polysilanol siloxanes 11a-c resulted in the formation of POSSs in high yields depending on the structure of substrates.
Composition, insulating film and process for producing the same
A composition comprising at least one of a compound represented by formula (I); a hydrolysate of the compound represented by formula (I); and a condensate of the compound represented by formula (I) and the hydrolysate of the compound represented by formula (I): wherein R1 represents a hydrogen atom or a substituent; R2 represents a hydrogen atom, an alkyl group, an aryl group, an acyl group, an arylcarbonyl group, a group having a quaternary ammonium atom or a metal atom; and m represents an integer of from 6 to 30.
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(2008/06/13)
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