Intercalation of n-alkylamines and alkylene diamines into carboxyl functionalized lamellar-type silsesquioxane

A sol–gel-derived carboxyl-functionalized lamellar-type silsesquioxane was prepared to investigate its potential for use as a host material for intercalation reactions with n-alkylamines and alkylene diamines. Upon intercalation of n-alkylamines and alkylene diamines, the interlayer distances increased as shown by X-ray powder diffraction patterns, and IR spectra showed the presence of absorption bands attributable to ν(COO−) and δ(NH3+) modes. The amounts of intercalated n-alkylamines were determined from n-CnH2n+1NH2/–COOH molar ratios which, based on CHN analysis, exhibited values from 0.76 to 0.88; whereas the values determined for the alkylene diamines were 0.83 (NH2C4H8NH2), 0.45 (NH2C8H16NH2) and 0.33 (NH2C12H24NH2). These results show that intercalation of n-alkylamines and alkylene diamines into lamellar-type silsesquioxane bearing carboxyl groups proceeded successfully via acid-base mechanisms.