Separation of contributions to the third-order signal: ultrafast frequency-selected vibrational echo experiments on a metalloporphyrin-CO

摘要

One-dimensional and frequency-selected vibrational echo experiments on the CO stretching mode of a metalloporphyrin carbonyl compound (model heme) in poly-methylmethacrylate (PMMA) and in 2-methytteterahydrofuran (2-MTHF) are compared. Spectrally resolving the vibrational echo signal and observing the decay at selected wavelengths, permits the independent detection of the 0-1 and 1-2 vibrational level dephasing dynamics, eliminating cross terms and anharmonic beats. In the high temperature 2-MTHF liquid. 0-1 and 1-21 dephasing dynamics are identical within experimental error. The decays are non-exponential, demonstrating that the CO stretching mode absorption spectrum is not a completely homogeneous. motionally narrowed line. (C) 2002 Elsevier Science B.V. All rights reserved. [References: 33]