Clean Singlet Oxygen Production by a ReI Complex Embedded in a Flexible Self-Standing Polymeric Silsesquioxane Film

Abstract

Rhenium complexes are versatile molecular building blocks whose tunable photophysical properties are useful in diverse opto-related applications. Herein we report the synthesis and characterization of a novel ReI tricarbonyldiimine complex, [(phen)Re(CO)3Br] (phen: 1,10-phenanthroline), which was found to be an efficient singlet oxygen [O2(1Δg)] photosensitizer in homogeneous solution [ΦO2(1Δg) = 0.55 (dichloromethane) and 0.16 (dimethylformamide)]. The photophysical properties of [(phen)Re(CO)3Br] were thoroughly characterized in solution and modeled by means of density functional theory (DFT) and time-dependent (TD)-DFT quantum mechanical calculations. The Re complex was incorporated into a flexible polymeric silsesquioxane (SSO) film, which has excellent dopant compatibility, chemical resistance, and mechanical properties. When [(phen)Re(CO)3Br] is embedded in the SSO film, it is found to retain most of the photophysical characteristics observed for the complex in solution. In particular, the [(phen)Re...