Infrared cavity ringdown spectroscopy of the water cluster bending vibrations

The first characterization of the monomer bending vibrations in gaseous water clusters was conducted by using infrared cavity ringdown spectroscopy. Discrete and sequentially blue-shifted bands near 6 microns for n = 2-4 and unresolved broad features for n > 4, supporting both theoretical computations and solid-state spectroscopy results were obtained. These measurements offer a measure of the monomer distortion that accompanies sequential hydrogen bond formation.