Organic-inorganic hybrid material as zwitterion:Synthesis and structure of terminal ammonium ions-containing organosilyl species supported on mono-lacunary Dawson polyoxometalate

摘要

The title compound 1 with a formula of(Bu4N)4[alpha 2-P2W17O61{Me3N~+(CH2)3Si}2O]·CH3CN was obtained in 77.1%(4.21 g scale)yield by a 1:2 molar-ratio reaction of the mono-lacunary Dawson polyoxometalate(POM)[P2W17O61]~(10-)with N-trimethoxysilylpro-pyl-N,N,N-trmethylammonium chloride([Me3N(CH2)3Si(OMe)3]Cl)in mixed water/acetonitrile solution under acidic conditions and unequivocally characterized with complete elemental analysis,thermogravimetric and differential thermal analyses(TG/DTA),FUR,solution(~(31)P, ~1H,~(13)C and ~(29)Si)NMR and X-ray crystallography.Compound 1 contained two types of the ammonium cations,i.e.,the counterions BU4N~+(free cations)and the terminal quaternary ammonium ions(bound cations)which are connected to the POM through the organosilyl groups.