Two-Dimensional Infrared Study of 13C-Natural Abundant Vibrational Transition Reveals Intramolecular Vibrational Redistribution Rather than Fluxional Exchange in Mn(CO)5Br
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- 作者：Fan Yang ; Juan Zhao ; Jianping Wang
- 刊名：Journal of Physical Chemistry B
- 出版年：2016
- 出版时间：February 25, 2016
- 年：2016
- 卷：120
- 期：7
- 页码：1304-1311
- 全文大小：381K
- ISSN：1520-5207
文摘
In this work, molecular-symmetry enhanced 13CO natural abundant isotopic infrared transition was identified in Mn(CO)5Br dissolved in CCl4 by FTIR spectroscopy. Diagonal and associated off-diagonal two-dimensional IR (2D IR) peaks of the 13CO-species were found to be spectrally separated from the all-12CO species, allowing a direct probe of the 13C natural abundant ensemble. Temperature-dependent FTIR experiment showed no evidence of ligand exchange in the metal carbonyl complex. Intramolecular vibrational redistribution dynamics among the CO stretching vibrational states were extracted using population-time dependent 2D IR diagonal and off-diagonal peaks for both radial mono-13CO and all-12CO isotopomers. This work demonstrates the potential use of natural abundant isotopic molecular species as a probe for revealing equilibrium and nonequilibrium structural dynamics in condensed-phase molecular systems.