Other types of covalent binding

Bisazomethines derived from suitable dialdehydes were condensed on the surface of wide-pore silica gels for testing the distance selectivity. The most promising substances for the condensation were of the type RSi(CH3)(OCH3)2 (entry c). The residual free silanol groups on the surface were then blocked by hexamethyldisila-zane to prevent non-specific adsorption. After cleavage of the template, two amino groups were left behind at a definite distance apart (Fig. 4.4). 

COVALENT BINDING AS SCHIFF BASES, KETALS, ESTERS AND DISULPHIDES 

Using a trialdehyde as template it was also possible to introduce three amino groups as a TRIPOD on the silica surface [85]. 

Molecular imprinting with covalent or stoichiometric non-covalent interactions (H3C0)2SI— y-CHt—W=CH— y— y-CH=N-CH2— KOCHah 

HPLC SEPARATIONS WITH THE SILICA GEL DESCRIBED IN FIG. 4.4 (LOADING 4.23 x 10 MMOL NH2 GROUPS PER GRAM). CAPACITY FACTORS k ) OF SOME DICARBOXYLIC ACIDS WITH VARIOUS DISTANCES d) 

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