Ultrafast vibrational spectroscopy of a degenerate mode of guanidinium chloride
Nearly degenerate asymmetric stretches with perpendicular transition dipóle moments of the deuterated guanidinium cation (DGdm-) in D2O and D-glycerol/D2O mixtures at 1600 cm-1 were investigated by linear FTIR spectroscopy and polarization dependent femtosecond pump-probe spectroscopy. The vibrational coupling of the asymmetric stretches of guanidinium occurs within 0.5 ps and leads to fast decay of the anisotropy to a level of 0.1. A systematic study of the influence of the coherence transfer on pump-probe signals is given. Following this decay, the anisotropy decays with a time constant of 4.1 ps in D2O by rotational diffusion about an axis perpendicular to the DGdm- mean plane. The presence of aggregation was demonstrated for concentrations higher than 0.2 M. © 2009 American Chemical Society.
Publication Source (Journal or Book title)
Journal of Physical Chemistry B
Vorobyev, D., Kuo, C., Chen, J., Kuroda, D., Nathan Scott, J., Vanderkooi, J., & Hochstrasser, R. (2009). Ultrafast vibrational spectroscopy of a degenerate mode of guanidinium chloride. Journal of Physical Chemistry B, 113 (46), 15382-15391. https://doi.org/10.1021/jp9069256