Structure and thermodynamics of gaseous oxides, hydroxides, and mixed oxohydroxides of chromium: CrOm(OH)(n) (m, n = 0-2) and CrO3. A computational study

The geometric structure of nine gaseous molecules obeying the generic formu la CrOm(OH)(n) has been determined by gradient-corrected density functional theory, with good agreement with experimental values where available. Cr-l igand bond energies have been determined for all of the molecules by use of the high-level ab initio method CCSD(T) in conjunction with PCI-X and G2(M P2/CC) extrapolation schemes. In combination with computed harmonic vibrati onal frequencies, the bond dissociation energies are used to form enthalpie s of formation. The resulting set represents the best set of consistent val ues available for the title molecules.