Ligand influence on the electronic spectra of monocationic copper-bipyridine complexes

• Published in: Physical chemistry chemical physics : PCCP Vol. 17; no. 47; pp. 31938 - 31946
• Main Authors: Xu, Shuang, Gozem, Samer, Krylov, Anna I, Christopher, Casey R, Weber, J Mathias
• Format: Journal Article
• Language: English
• Published: England 01.01.2015
• Subjects: Band spectra; Constraining; Contours; Excitation; Ligands; Mathematical analysis; Photodissociation; Physical chemistry
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/c5cp05063d

We present photodissociation spectroscopy and computational analysis of three monocationic Cu-bipyridine complexes with one additional ligand of different interaction strength (N2, H2O and Cl) in the visible and UV. All three complexes show similar ππ* bands with origins slightly above 4 eV and vibrational band contours that are due to bipyridine ring deformation modes. Experiments at low temperature show that excited-state lifetime is the limiting factor for the width of the vibrational features. In the case of Cl as a ligand, there is a lower lying bright ligand-to-ligand charge-transfer state around 2.75 eV. The assignment of the transitions was made based on equation-of-motion coupled-cluster calculations. While the nature of the ligand does not significantly change the position of the bright ππ* state, it drastically changes the excited-state dynamics.