Rhenium diimine complex changes

Fig. 18 The structure of rhenium(I) tricarbonyl diimine complex for anion sensing and the absorption spectral changes of this probe molecule (2.5 x 10 5 M) in CII )CN upon addition of n-Bu4NF, (a) [F ] = 0 - 2.8 x 10 5 M and (b) [F ] = 2.8 x 10 5 - 1.1 x 10 4 M. (reproduced with permission from [155])...

Another important type of LLCT state arising in diimine rhenium(I) tricarbonyl complexes is found in IRe (CO)3(diimine) complexes. When I replaces Cl or Br, the lowest excited states changes from being MLCT in nature to that of XLCT (halide-to-ligand charge transfer) in character. Figure 2 clearly shows that the lowest energy band of the transient absorption... 

This case study deals with different photophysical properties of a variety of diimine rhenium(I) tricarbonyl complexes. The exceptionally diverse photophysical behavior of these complexes is largely dependent on the nature of their lowest excited states. Varying the substituents on either the diimine ligands or ancillary ligands can easily change the relative order of these excited states and provides a way to tune the excited-state characteristics. A range of important applications is now becoming apparent, based on the richness of the photophysical and photochemical properties of diimine rhenium(I) tricarbonyl complexes. 

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