Syntheses and characterization of luminescent polymers containing rhenium(I) pyridinyl-carbonyl complexes

The syntheses of methacrylate and styrene-based monomers containing substituted pyridine ligands are reported. The preparation of the corresponding homopolymers has been performed by free radical polymerization by using 2,2'-azoisobutyronile (AIBN) at 60degreesC. The high molecular weights up to 119000 g . mol(-1) and low glass transition (T-g) values (< -43 degrees C) have been obtained by the copolymerization reaction with butylacrylate. The free metal homopolymer and copolymer were subsequently metalated by reaction with Re[phen(CO)(3)(acetone)](+). All polymer materials have been characterized by conventional experimental techniques such as gel permeation chromatography (GPC), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). UV-Vis and fluorescene spectroscopy have been used to investigate the optical and photophysical properties of the polymers in solid-state films and in solution. H-1 NMR spectra confirmed the structure of the synthesized polymers and contributed to the estimate of the monomer sequences in the copolymer chains. Time-resolved and emission-quenching experiments in diluted solution sand on the solid films suggest application of the polymeric materials as oxygen sensors. The morphological aspects of some polymers containing a low amount of rhenium metal complexes have been investigated by scanning electron microscopy (SEM).