Photochemically Induced Isomerisation of Ruthenium Polypyridyl Complexes

Abstract

The synthesis and characterisation of a series of ruthenium polypyridyl complexes containing pyridyltriazole ligands in different coordination modes are described. The electrochemical and electronic properties of the compounds with respect to the coordination mode of the pyridyltriazole ligand are reported. Upon photolysis of the complex containing the 1‐methyl‐3‐(pyridin‐2‐yl)‐1,2,4‐triazole ligand, irreversible ligand isomerisation is observed.

An overview of photosubstitution reactions of Ru(II) imine complexes and their application in photobiology and photodynamic therapy

“…The work serves as affirmation of formation of monodentate intermediates from bidentate ligands in the process of net loss of the bidentate ligand. Irreversible photoisomerization of Ru(II) complexes of the closely related 1-methyl-3-(pyridin-2-yl)-1,2,4-triazole was also reported by Fanni et al 65 …”

Photoinduced ligand isomerisation in a pyrazine-containing ruthenium polypyridyl complex

“…However, for complexes containing protonated or methylated triazole ligands the 3 MC level is stabilised and photolability observed. 11,12,13 As a result photoinduced ligand dissociation processes are observed where the triazole ligand is not anionic. For [Ru(bpy) 2 (Hpytr)] 2+ there are two coordination isomers possible where the Hpytr ligand is bound either via the N2 or the N4 nitrogen atom of the triazole ring (Fig.…”

Photoinduced rearrangements in transition metal compounds

“…This is related to the strong sigma donor capacity of the deprotonated triazole ring. This leads to a considerable increase in the energy of the deactivating 3 MC level (Figure 1) ( Figure 9) [47]. This shows interactions between the pyridine group and the phenanthroline ligand in the starting material and pyridine mesityl interaction for the photoproduct.…”