DETERMINATION OF THE STRUCTURE OF ALKOXYSILANE POLYMERS IN SOLUTION BY NATURAL-ABUNDANCE 2-DIMENSIONAL SI-29-SI-29 INEPT DQF COSY NMR

In order to determine the nature and the structure of polymers formed by condensation of alkoxysilanes, a two-dimensional INEPT double quant um filtered COSY NMR experiment was developed to observe Si-29-Si-29 c orrelations at Si-29 natural abundance. This experiment was tested on a mixture containing a trimer, [(CH3)3SiO]2Si(CH3)2, and a tetramer, [ (CH3)3SiOSi(CH3)2]2O. This 2D INEPT DQF COSY experiment was then used to investigate the nature and the structure of the polymers which are formed in the early stages of the condensation reaction of diethoxydim ethylsilane (DEDMS) in a DEDMS-water mixture containing a small amount of water at low pH (1.0).