Abstract
Four chiral diureido derivatives of trans-(1R,2R)- and trans-(1S,2S)-diaminocyclohexane with different carbon chain lengths (n = 3, 4, 5, 10) were synthesized and were hydrolyzed in aqueous acidic conditions in order to examine the role of the carbon chain spacer on the resulting hybrid bridged silsesquioxanes. Solid state NMR (29Si and 13C) studies demonstrated the presence of covalently bonded organo-bridged silica networks in these materials. Scanning electron microscopy (SEM) showed the materials obtained from the short chain derivatives to consist of fibers (n = 3 and 4). In contrast, plate-like shapes were formed from the longer chain precursors (n = 5 and 10). A lamellar structure was observed via transmission electron microscopy (TEM) for the hybrid obtained from the precursor with the longest chain (n = 10). This lamellar form was confirmed by powder X-ray diffraction (PXRD) measurement of the hybrid.