The structure of phenol(H2O) obtained by microwave spectroscopy

The microwave spectrum of phenol(H2O) has been recorded using a pulsed molecular beam Fourier transform microwave spectrometer. Twenty a-type transitions have been observed and assigned. All a-type transitions are doublets with splittings varying from 1.13 to 4.01 MHz. These splittings are interpreted to result from the internal rotation of the water molecule. The ground state of this torsional motion is split into two levels with different spin statistical weights. Both torsional levels are treated independently as asymmetric rotor states. The resulting rotational constants are A=4291.486 MHz, B=1092.1484 MHz, and C=873.7263 MHz for the lower torsional level (sigma=0) and A=4281.748 MHz, B=1092.329 55 MHz, and C=873.906 81 MHz for the upper level (sigma=1). A fit of the molecular structure is performed by optimizing the intermolecular OO distance and two angles, describing the H-bonding arrangement. The resulting trans-linear structure is in reasonable agreement with the ab initio, calculations (C) 1996 American Institute of Physics.