Two-dimensional infrared spectroscopy

Pulse sequence used to obtain a two-dimensional Fourier transform infrared spectrum: is the coherence time, is the waiting time. The Fourier transform with respect to provides the excitation spectrum (frequency ).

Two-dimensional infrared spectroscopy (2D IR) is a nonlinear infrared spectroscopy technique that has the ability to correlate vibrational modes in condensed-phase systems. This technique provides information beyond linear infrared spectra, by spreading the vibrational information along multiple axes, yielding a frequency correlation spectrum.[1][2] A frequency correlation spectrum can offer structural information such as vibrational mode coupling, anharmonicities, along with chemical dynamics such as energy transfer rates and molecular dynamics with femtosecond time resolution. 2DIR experiments have only become possible with the development of ultrafast lasers and the ability to generate femtosecond infrared pulses.

  1. ^ P. Hamm; M. H. Lim; R. M. Hochstrasser (1998). "Structure of the amide I band of peptides measured by femtosecond nonlinear-infrared spectroscopy". J. Phys. Chem. B. 102 (31): 6123. doi:10.1021/jp9813286.
  2. ^ Zanni, M.; Hochstrasser, RM (2001). "Two-dimensional infrared spectroscopy: a promising new method for the time resolution of structures". Current Opinion in Structural Biology. 11 (5): 516–22. doi:10.1016/S0959-440X(00)00243-8. PMID 11785750.