Early photochemical dynamics of organometallic compounds studied by ultrafast time-resolved spectroscopic techniques

Abstract

Time-resolved spectroscopic techniques operating on a femtosecond–picosecond time scale are used to investigate mechanisms and dynamics of the earliest stages of photochemical reactions of organometallic compounds, as well as the composition and structure of the excited states and photointermediates involved. A deep insight into the following ultrafast photochemical reactions: (i) Cr–CO bond dissociation in [Cr(CO)₄(bpy)], (ii) dissociative isomerisation of [Mn(Br)(CO)₃(α-diimine)] and (iii) interligand electron transfer in [Re(MQ⁺)(CO)₃(dmb)]²⁺ has been obtained by combining time-resolved visible and IR absorption, resonance Raman and fluorescence spectroscopic techniques. In each case, it is demonstrated what kind of information individual approaches provide and how the photochemical mechanism can be deduced. The operating principles of these ultrafast spectroscopic techniques are briefly explained, together with descriptions of the experimental setups used for the above mentioned studies.