Near-infrared and visible luminescence and absorption spectroscopy of low-coordinate organometallic rhenium compounds

Abstract

Low-temperature absorption and luminescence spectra of four organorhenium compounds were measured in the visible and near-infrared spectral regions. Effects of the temperature, formal oxidation state, and the 0x0-, bromo-, and organic ligands on the metal center are reported. The emission maxima of the four compounds show a large variation between 9000 and 14 200 cm-I. Stokes shifts show a smaller variation from 3700 to 4200 cm-I. Luminescence intensities are used to qualitatively characterize nonradiative relaxation processes.

Complexation of Unsaturated Carbon−Carbon Bonds in π-Conjugated Polymers with Transition Metals

“…Among a plethora of functional groups which may serve as ligands for transition metals, we here focus on the utilization of unsaturated (acyclic) carbon−carbon bonds as potential binding sites. These moieties allow the formation of a wide variety of metal complexes that access a broad spectrum of interesting electronic characteristics , and have also previously been used for the synthesis of organometallic polymer systems; the polymeric silyl acetylene−cobalt−carbonyl complexes introduced by Corriu and co-workers provide a prominent example for the latter . However, the concept of directly employing ethynylene or vinylene moieties for the controlled formation of metal-complexed macromoleculesto our best knowledgehas never been adapted for π -conjugated polymers .…”