![Sample our Physical Sciences journals, sign in here to start your FREE access for 14 days]({"type":"image" , "src" : "/sda/110819/TOC-Subject-Sample-2021-Physical-Sciences.jpg"})
Graphical Abstract
Abstract
The mechanism associated with the cis- to trans-photoisomerization of Ru(II)(2,2’-bipyridine)2(H2O)2 ([Ru(bpy)2(H2O)2]2+) complex in water has been examined using photoacoustic calorimetry (PAC) and density functional theory (DFT). Photolysis of the cis-[Ru(bpy)2(H2O)2]2+ complex results in a ΔH of -27 ±5 kcal mol–1 and ΔV of 0.1±2 mL mol–1. The DFT calculations give a ΔEcis-trans of +12 kcal mol–1, indicating that the observed ΔH contains significant contributions from changes in solvation. The DFT analysis of putative intermediates [Ru(bpy)2(H2O)]2+ and [Ru(bpy)2(H2O)3]2+ suggests the possibility of an associative mechanism for the isomerization process.
ACKNOWLEDGMENTS
The authors would like to thank Research Computing at the University of South Florida and XSEDE for computer time.
FUNDING
The authors acknowledge the University of South Florida Office of Research and Innovation for support of this work.
NOMENCLATURE
[Ru(bpy)2(H2O)]2+: Ru(II)bis(2,2’-bipyridine)(H2O)2;
3MLCT: triplet metal to ligand charge transfer transition;
DFT: density functional theory.