STRUCTURAL INVESTIGATION OF A NEW POLYORGANOSILOXANE CONTAINING NANOTUBULAR CAVITIES USING ORGANIC FLUORESCENT PROBES*

Fluorescent molecules - p-dimethylaminobenzonitrile (DMABN) and trans-stilbene (TSB) -were used as probes to investigate the inner structure of the nanotubular cavities contained in a newpolyorganosiloxane (POS) which was prepared by the hydrosilylation coupling reaction of cis-isotacticladderlike polyvinylsilsesquioxane (Vi-T) with 1, 1,3,3-tetramethyldisiloxane (H-MM) as coupling agent inthe presence of catalyst dicyclopentadienyldichloroplatin (Cp_2PtCl_2). The results from FTIR spectra andfluorescence spectra in combination with molecular simulation revcal that the cross-section of thenanotubular cavity is nearly rectangular in shape, and is about 0.62 nm in width and about 0.38 nm in height.This work gains in-depth knowledge into the inner structure of the nanotubular cavities of POS andfurthermore provides a guide to the selection of proper guest molecules in constructing functionalsupramolecular clathrate based upon POS.