Polymer, Vol.47, No.19, 6598-6605, 2006
Polybinaphthyls incorporating chiral 2,2'-binaphthyl and isoquinoline moieties by Sonogashira reaction
Polymers P-1, P-2, P-3, P-4 and P-5 were synthesized by the polymerization of 5,8-bis(ethynyl)isoquinoline (M-1) with (R)-3,3'-diiodo-2,2'-bisbutoxy-1,1'-binaphthyl ((R)-M-2), (S)-3,3'-diiodo-2,2'-bisbutoxy-1,1'-binaphthyl ((S)-M-2), (R)-6,6'-dibromo-2,2'-bisbutoxy-1,1'-binaphthyl ((R)-M-3), (S)-6,6'-dibromo-2,2'-bisbutoxy-1,1'-binaphthyl ((S)-M-3), and rac-6,6'-dibromo-2,2'-bisbutoxy-1,1'-binaphthyl (M-4) under Sonogashira reaction, respectively. Both monomers and polymers were analyzed by NMR, MS, FT-IR, UV-vis spectroscopy, DSC-TGA, fluorescence spectroscopy, GPC and circular dichroism (CD) spectroscopy. CD spectra of polymers P-1 and P-2, P-3 and P-4 are almost identical except that they gave opposite signals at each wavelength. The long wavelength CD effect of P-1 and P-2 can be regarded as the more extended conjugated structure in the repeating unit and the helical backbone in the polymer chain. All five polymers have strong blue-green fluorescence due to the efficient energy migration from the extended pi-electronic structure of the repeating unit of the polymers to the chiral binaphthyl core and are expected to provide understanding of structure-property relationships of the chiral conjugated polymers. (c) 2006 Elsevier Ltd. All rights reserved.