Rhenium diimine carbonyl

Photophysical Properties of Rhenium Carbonyl Diimine Complexes... 

Keywords rhenium carbonyl diimine photophysics excited state electron transfer charge transfer relaxation intersystem crossing DFT time-resolved IR spectroscopy... 

Rhenium carbonyl-diimine complexes were discovered in the mid 1970s [44, 45] as strongly emissive complexes. The long emission lifetime (tens-hundreds of ns) and structureless and broad shapes of emission bands and a prominent rigidochromism... 

The MLCT emission properties of many rhenium(I) carbonyl diimine complexes have been used to demonstrate the energy-gap law. For example, the complexes [Re(N-N)(CO)3(L)] (N N = bpy, phen, 5-Ph-phen L = substituted pyridines or quinoline) displayed MLCT (d7r(Re)- 7t (N-N)) phosphorescence at room temperature. The radiationless decay-rate constants depended on the emission energy as described in the energy-gap law (Inknr A-B fern) From the Hammett constant of the substituent, both the emission energy and hfetime of related complexes can be predicted. ... 

Rhenium(I) diimine carbonyl complexes have been well investigated because of their functionalities, such as the intense emission properties, capabilities as a building block for multinu-clear complexes, and photocatalytic activities. 

In addition, the family of rhenium(I) diimine carbonyl complexes/he-[Re(LL)(CO)2(X)(Y)]" (LL = a-diimine) has imique properties and application as follows ... 

In this chapter, we focus on these imique photochemical properties of rhenium(I) diimine carbonyl complexes (Fig. 1), especially photochemical reactions and photocatalysis. 

The MLCT emission properties of many rhenium (I) carbonyl diimine complexes have been nsed to demonstrate the energy-gap law. For example, the complexes [Re (N-N) (CO) 3(E)] (N-N = bpy, phen, 5-Ph-... 

Gindensperger E, Koppel H, Daniel C (2010) Mechanism of visible-light photoisomerization of a Rhenium(I) carbonyl-diimine complex. Chem Comm 46 8225-8227... 

When more conjugated diimine or pyridine ligands are used, the excited states of rhenium(I) carbonyl complexes can have substantial IL character. While the MLCT emission is often broad, with a lifetime in the submicrosecond to microsecond timescale, the IL emission usually has noticeable structural features, even in fluid solutions at ambient temperature. The emission lifetime is usually very long. A simple and widely applicable approach is to evaluate the ratio of the emission quantum yield and the emission lifetime (the product of the intersystem crossing efficiency and radiative decay-rate constant). Experimental values of... 

The last section describes rmique and high photocatal5rtic activities of the rheniiun(I) diimine carbonyl complexes, especially for CO2 reduction. The photocatalyses of mononuclear rhenium complexes, multicomponent systems, supramolecular systems with a Ru(II) complex as a photosensitizer, and a rhenium complex with periodic mesoporous organosilica as a light-harvesting system. 

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