Determination of the structure of alkoxysilane polymers in solution by natural abundance two dimensional 29Si‐29Si 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 quantum filtered COSY NMR experiment was developed to observe 29 Su- 29 Si correlations at 29 Si natural abundance. This experiment was tested on a mixture containing a trimer, [(CH 3 ) 3 SiO] 2 Si(CH 3 ) 2 , and tetramer, [(CH 3 ) 3 SiOSi(CH 3 ) 2 ] 2 O. 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 diethoxydimethylsilane (DEDMS) in a DEDMS-water mixture containing a small amount of water at low pH(1.0)