Direct absorption spectroscopy of water clusters

Fourier Transform infrared spectrometry has been used to study the vibratio nal spectroscopy of water clusters prepared in a supersonic expansion. The clusters are assigned as being composed of 10-100 waters based on considera tion of the free OH and bound OH vibrations and the experimental conditions used. Four vibrational features were observed simultaneously including the bend, free OH stretch, bound OH stretch, and an unresolved group of interm olecular vibrations. No absorption features were observed between 4000 and 8000 cm(-1). This is the first observation of the bending vibration for any size gas-phase water cluster.