Silanol hydrogen bonded

The strength of the self-associated silanol hydrogen bonds were reduced considerably with increased steric hindrance of the substituents. The infrared frequency shifts, as a measure of the strength of the silanol self-association between the free and self-associated silanol hydrogen bonds in the silanol stretching vibration region, were... 

Figure 9. Schematic representation of active groups on silica surfaces (A) isolated silanols (B) siloxane bonds (C) geminal silanols (D) hydrogen-bonded silanols ( ) hydrogen-bonded water. (Reproduced with permission from L. Johnston in Photochemistry in Organized and Constrained Media, V. Ramamurthy, Ed., VCH, New York, 1991, p. 359.)...

Kohler and Kirkland noted that for chromatographic column packings analyzed by diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy and chromatographic behavior, silica appears to possess associated and isolated surface silanol groups [ I9. The associated silanol (possessing weak-acid characteristics) is identified with a silanol hydrogen-bonded to its nearest neigh-... 

Keywords siloxane, silanol, hydrogen bonding, Si NMR, X-ray diffiaction... 

Reaction of Cp2TiCl2 with premodified silica gel surfaces has been studied. The silica gel surface was pretreated to selectively eliminate non-hydrogen-bonded silanols, hydrogen-bonded silanols, or both before reaction. It has been found that the titanium compound reacts predominantly with the non-hydrogen-bonded silanols.1546... 

A new convenient polymer modification has been developed to synthesize a series of novel silanol-containing polymers by a selective oxidation of Si—containing precursor polymers with a dimethyldioxirane solution in acetone. The silanol hydrogen bonding interactions in polymer blends as well as the silanol self-condensation to form siloxane semi-interpenetrating polymer networks in miscible polymer blends and organic-inorganic polymeric hybrids are discussed. 

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