Abstract
Ab initio self-consistent-field calculations using effective care potentials and polarized double-ζ basis sets are reported for the title
compounds and the analogous phosphorus compounds. The most stable trigonal-bipyramidal isomers of the fluoroarsoranes are those with the maximum number of axial fluorine atoms, as in the case of the fluorophosphoranes. For the known molecules AsH3, AsF3, and AsF5, the calculated geometries and vibrational frequencies agree well with the experimental data, and improvements
to the current empirical force field of AsF5, are suggested. Predictions are made for the vibrational spectra of the other molecules,
which are unknown, and plots of the calculated gas-phase infrared spectra at 300 K are presented for ASH5, AsH4F, and AsH3F2,
as an aid to their spectroscopic identification. Trends in the calculated properties of the fluoroarsoranes are discussed and found to be very similar to those for the fluorophosphoranes.
