Compounds of [btilde]-Cyclodextrin and Organosilicon Oligomers

Products of hydrolysis and condensation of organosilicon monomers in the presence of [btilde]-cyclodextrin (cycloheptaamylose [btilde]-CD) were studied by IR, NMR, MS, and x-ray methods. It was established that when an aqueous solution of [btilde]-CD is treated with dimethyldichlorosilane (DMDCS), diphenyldichlorosilane (DFDCS), methylphenyldichlorosilane (MFDCS), or with a mixture of the DMDCS and DFDCS, crystalline compounds of cyclodextrin with appropriate siloxane oligomers, are formed: /3-CD-MSO (69% yield by weight), [btilde] -CD-FSO (6.0% yield by weight), [btilde]-CD-MFSO (16%) yield by weight), [btilde]-CD-(MSO + FSO) (22–63% yield by weight). The content of the obtained products showed: [btilde]-CD:MSO = 1 mole of [btilde]-CD:2 (CH3)2SiO elements; [btilde]-CD:FSO = 1 mole of [btilde]-CD:0.57 mole of (C6H5)2SiO; [btilde]-CD:MFSO = 1 mole of [btilde]-CD:0.87 mole of (CH3) (C6H5)SiO. Contents of [btilde]-CD′ (MSO + FSO) depend on the starting monomer mixture. It is suggested that nonchemical bonds between [btilde]-CD molecules and siloxane elements occur. The topological structure of the obtained substances is analyzed. Analogous compounds are not formed with methyltrichlorosilane, triphenylchlorosilane, diethoxydichlorosilane, dimethyldimethoxysilane, dimethyl -diacetoxysilane, or silica tetrachloride. Compounds with [btilde]-cyclodextrin are not formed from already formed siloxane oligomers. In the processes described above, linear dextrins show a total lack of activity. Methylsiloxanes bound with [btilde]-CD have a cyclic structure, while phenyl ones probably have a linear structure.