A Theoretical Study of the N to O Linkage Photoisomerization Efficiency in a Series of Ruthenium Mononitrosyl Complexes

Molecules. 2017 Oct 6;22(10):1667. doi: 10.3390/molecules22101667.

Abstract

Ruthenium nitrosyl complexes are fascinating versatile photoactive molecules that can either undergo NO linkage photoisomerization or NO photorelease. The photochromic response of three ruthenium mononitrosyl complexes, trans-[RuCl(NO)(py)₄]2+, trans-[RuBr(NO)(py)₄]2+, and trans-(Cl,Cl)[RuCl₂(NO)(tpy)]⁺, has been investigated using density functional theory and time-dependent density functional theory. The N to O photoisomerization pathways and absorption properties of the various stable and metastable species have been computed, providing a simple rationalization of the photoconversion trend in this series of complexes. The dramatic decrease of the N to O photoisomerization efficiency going from the first to the last complex is mainly attributed to an increase of the photoproduct absorption at the irradiation wavelength, rather than a change in the photoisomerization pathways.

Keywords: computational photochemistry; density functional theory; photochromism; photoisomerization.

MeSH terms

  • Coordination Complexes / chemistry
  • Coordination Complexes / radiation effects*
  • Isomerism
  • Kinetics
  • Ligands
  • Light
  • Models, Molecular
  • Molecular Structure
  • Nitric Oxide / chemistry*
  • Quantum Theory
  • Ruthenium / chemistry*
  • Thermodynamics

Substances

  • Coordination Complexes
  • Ligands
  • Nitric Oxide
  • Ruthenium