Silica Hybrid Containing (R)-2,2′-Binaphtho-20-crown-6 Moieties via the Sol-Gel Process

(R)-6,6′-Bis (triethoxysilylethen-2-yl)-2,2′-binaphtho-20-crown6 (precursor, R-2) derived from (R)-2,2′-BINOL derivative was synthesized by Pd-catalyzed Heck reaction of (R)-6,6′-dibromo-2, 2′-binaphtho-20-crown-6 (R-1) intermediate with vinyltriethoxysilane. The hydrolysis and polycondensation of the precursor gave rise to the corresponding xerogel. Both precursor and xerogel were analysed by NMR, FT. IR, UV, CD spectra, fluorescent spectroscopy, polarimetry and elemental analysis. The precursor and xerogel can emit strong blue fluorescence and are expected to have the potential application in the separation of chiral molecules as fluorescent sensor. The precursor exhibits strong Cotton effect in its circular dichroism (CD) spectrum indicating that it is a highly rigid structure.