Two dimensional infrared spectroscopy and relaxation of aqueous cyanide

The 2D IR spectra of water in the region of the bending/librational mode near 5 μm and the cyanide ion whose vibrational mode is in the same frequency range show that the combination mode and the cyanide mode undergo spectral diffusion on ultrafast time scales. The signals are dominated by a water grating formed by energy deposition following infrared excitation. The grating is formed more rapidly from the combination mode than from the water background mode excitation indicating more effective breaking and making of hydrogen bonds.