Using picosecond and nanosecond time-resolved infrared spectroscopy for the investigation of excited states and reaction intermediates of inorganic systems

Time-resolved infrared (TRIR) spectroscopy, a combination of UV flash photolysis and fast infrared detection, is a powerful technique for probing excited states and detecting reaction intermediates. In this Perspective we highlight the application of TRIR to excited states by probing the nature of the lowest excited states of fac-[Re(CO)3(dppz-Cl2)(R)]n+(R = Cl-(n= 0), py (n= 1) and 4-Me2N-py (n= 1); dppz-Cl2= 11,12-dichlorodipyrido[3,2-a:2,3-c]phenazine) in CH3CN. The characterisation of [Cr((eta)^6-C6H6)(CO)2Xe] and [Re ((eta)^5-C5H5)(CO)2(C2H6)] in supercritical Xe and liquid ethane solution exemplifies how this technique can be applied to detect new organometallic species.