| 概 要 |
Energy transport through vibrational modes in peptides can now be studied in detail using two-dimensional infrared (2DIR) spectroscopy.
To understand how experimental data should be interpreted, we have modeled the coupled dynamics in the amide I and II modes in a short alpha helix dissolved in water. From these simulations, time constants for thepartially coherent transport within the amide I band, as well as for the relaxation to the amide II band can be obtained. The connection with observables is made by investigating how these time constants can be extracted from the simulated 2DIR spectra.
We find that both the intra- and interband dynamics can be recovered, but only when the collective nature of the vibrations is properly taken into account. This analysis may also be applied to other two-band systems, both in the infrared (collective vibrations) and the visible (excitons) parts of the spectrum.
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