Mono- and binuclear complexes of (Re(CO)3Cl) with dipyrido[2,3-a:3′,2′-c]-6,7-dimethylphenazine (ppbMe2) were synthesised and their photophysical properties probed using picosecond time-resolved infrared spectroscopy (TRIR). Excitation of these complexes in solution at 400 nm produces short-lived excited states. The IR spectrum of the excited state of the mononuclear [Re(CO)3Cl(ppbMe2)] have ν(CO) bands shifted to higher wavenumber relative to those of the ground state. This is consistent with formation of a 3MLCT excited state. The IR spectrum of the excited state of the bimetallic [(Re(CO)3Cl)2(μ-ppbMe2)] shows the formation of two distinct groups of ν(CO) bands. This is interpreted as the formation of two distinct Re sites arising from a localised MLCT state with formally oxidised Re centre and a formally reduced bridging ligand. The ν(CO) bands of the adjacent Re centre are affected by the reduction of the bridging ligand. On the IR timescale the excited state structure is best formulated as [Cl(CO)3ReII(μ-ppbMe2˙-)ReI(CO)3Cl].
ASJC Scopus subject areas
- Physical and Theoretical Chemistry