Abstract

The excited state reactivity and photophysical properties of fac-[Re(CO)3(phen)(L)]PF6 (phen = 1,10-phenanthroline, L = trans- or cis-1,2-bis(4-pyridyl)ethylene, bpe) in PMMA (poly(methyl methacrylate)) films have been investigated and compared with those in acetonitrile solution.313 or 365 nm irradiation of the rhenium complex in PMMA leads to UV-vis spectral changes due to the trans→cis isomerization of the coordinated bpe ligand. The fac-[Re(CO)3(phen)(cis-bpe)]+ product presents a markedly enhanced luminescence due to a lower lying metal-to-ligand charge transfer (MLCT) excited state in the cis isomer. This emitting property can be conveniently applied as a probe or sensor.The cis is omer ratio in the photostationary state (PSS) is substantially smaller in solid films than in solution. The photochemical behavior of the free trans-1,2-bis(4-pyridyl)ethylene in PMMA is also reported to establish comparisons with the investigation carried out in acetonitrile solution as well as with the behavior of the coordinated ligand.