Jump to main content
Jump to site search

Issue 3, 2015
Previous Article Next Article

Vibrational energy transfer dynamics in ruthenium polypyridine transition metal complexes

Author affiliations

Abstract

Understanding the dynamics of the initial stages of vibrational energy transfer in transition metal complexes is a challenging fundamental question which is also of crucial importance for many applications, such as improving the performance of solar devices or photocatalysis. The present study investigates vibrational energy transport in the ground and the electronic excited state of Ru(4,4′-(COOEt)2-2,2-bpy)2(NCS)2, a close relative of the efficient “N3” dye used in dye-sensitized solar cells. Using the emerging technique of ultrafast two-dimensional infrared spectroscopy, we show that, similarly to other transition-metal complexes, the central Ru heavy atom acts as a “bottleneck” making the energy transfer from small ligands with high energy vibrational stretching frequencies less favorable and thereby affecting the efficiency of vibrational energy flow in the complex. Comparison of the vibrational relaxation times in the electronic ground and excited state of Ru(4,4′-(COOEt)2-2,2-bpy)2(NCS)2 shows that it is dramatically faster in the latter. We propose to explain this observation by the intramolecular electrostatic interactions between the thiocyanate group and partially oxidised Ru metal center, which increase the degree of vibrational coupling between CN and Ru–N modes in the excited state thus reducing structural and thermodynamic barriers that slow down vibrational relaxation and energy transport in the electronic ground state. As a very similar behavior was earlier observed in another transition-metal complex, Re(4,4′-(COOEt)2-2,2′-bpy)(CO)3Cl, we suggest that this effect in vibrational energy dynamics might be common for transition-metal complexes with heavy central atoms.

Graphical abstract: Vibrational energy transfer dynamics in ruthenium polypyridine transition metal complexes

Back to tab navigation

Article information


Submitted
16 Sep 2014
Accepted
19 Nov 2014
First published
24 Nov 2014

Phys. Chem. Chem. Phys., 2015,17, 1688-1696
Article type
Paper

Vibrational energy transfer dynamics in ruthenium polypyridine transition metal complexes

M. Fedoseeva, M. Delor, S. C. Parker, I. V. Sazanovich, M. Towrie, A. W. Parker and J. A. Weinstein, Phys. Chem. Chem. Phys., 2015, 17, 1688
DOI: 10.1039/C4CP04166F

Social activity

Search articles by author

Spotlight

Advertisements