Synthesis and characterization of a poly[2,7-(9,9-dioctylfluorene-alt-2,7-fluorene/β-CD)] main chain polyrotaxane

Poly[2,7-(9,9-dioctylfluorene-alt-2,7-fluorene/beta-CD)] main chain polyrotaxane was synthesized through organometallic Suzuki coupling by reacting beta-cyclodextrin/2,7-dibromofluorene inclusion complex with 9,9-dioctylfluorene-2,7-bis(trimethyleneborate). The IR, NMR and elemental analysis data support the presence of beta-cyclodextrin in the copolymer structure. No glass transition or melting phenomena were detected in DSC curves of the polyrotaxane on the heating run in the 50-250 degrees range. As compared with the reference copolymer obtained in the absence of beta-cyclodextrin, the rotaxane copolymer is more hygroscopic and soluble in polar/non-polar solvent mixtures. The expected modification of the optical properties of the fluorene copolymer with rotaxane architecture in the main chain was proved by fluorescence and UV-vis spectroscopy and consists in a blue-shifted emission. (C) 2008 Elsevier Ltd. All rights reserved.