@article {4555, title = {Fourier transform microwave spectrum, geometry, and hyperfine coupling constants of phosphenous fluoride, OPF}, journal = {Journal of Physical Chemistry A}, volume = {103}, number = {5}, year = {1999}, note = {ISI Document Delivery No.: 174PBTimes Cited: 6Cited Reference Count: 60}, month = {Feb}, pages = {560-567}, type = {Article}, abstract = {The microwave spectrum of phosphenous fluoride, OFF, has been measured using a pulsed-jet cavity Fourier transform microwave spectrometer. With the exception of a mass spectroscopic detection of the molecule, chemically prepared for use in a matrix IR study, this is the first observation of free gas-phase OFF. The samples were prepared from mixtures of PF3 and O-2 in Ne carrier gas, using an electric discharge. Rotational transitions of two isotopomers ((OPF)-O-16-P-31-F-19 and (OPF)-O-18-P-31-F-19) have been measured in the 4-26 GHz frequency range. The determined rotational constants have been used to calculate r(0), r(7), and approximate r(e) molecular geometries. In contrast to the nitrogen analogue, ONF, OFF has been found to show no irregularities in its geometry. Small hyperfine splittings due to the spin-1/2 P-31 and F-19 nuclei have been analyzed in terms of nuclear spin-rotation interactions. Because the determined coupling constants were of similar magnitudes and could not be unambiguously assigned, the related nuclear shielding parameters have been derived using both possible assignments. The spin-rotation coupling constants are compared with those calculated using ab initio techniques, and the F-19 nuclear shieldings are compared with those derived for the nitrogen analogue ONF.}, keywords = {BANDS, CL-35, DIPOLE, FORCE-FIELD, INFRARED-SPECTRA, MATRIX-IR INVESTIGATIONS, MOLECULES, N-14, NITROSYL CHLORIDE, SHIELDING TENSOR}, isbn = {1089-5639}, url = {://000079042600002}, author = {Gatehouse, B. and Brupbacher, T. and Gerry, M. C. L.} } @article {3981, title = {F-19 spin-rotation constants and shielding tensor of sulphur difluoride from its microwave spectrum}, journal = {Journal of Chemical Physics}, volume = {106}, number = {17}, year = {1997}, note = {ISI Document Delivery No.: WV763Times Cited: 12Cited Reference Count: 46}, month = {May}, pages = {6916-6922}, type = {Article}, abstract = {The microwave spectrum of the unstable molecule sulphur difluoride, SF2, prepared via a pulsed electric discharge in an SF6/OCS mixture, has been measured using a pulsed jet cavity Fourier transform spectrometer. F-19 hyperfine structure has been resolved, and unusually small, negative values have been determined for two of the spin-rotation coupling constants. These constants have been used to calculate the 19F principal, inertial axis nuclear shielding components; the determined paramagnetic shieldings are also unusual and produce a large positive average shielding, sigma(av). The shieldings have been compared with the corresponding constants obtained for OF2, SiF2, and GeF2. The results for SF2 are consistent with values determined from earlier NMR experiments and ab initio calculations. The origin of the unusual shieldings has been found, and is discussed, using a semi-quantitative model, in terms of the geometry and the electronic energy level structure of the molecule. (C) 1997 American Institute of Physics.}, keywords = {DIPOLE, DISCHARGE, ELECTRONIC-SPECTRUM, GAS-PHASE, HYPERFINE CONSTANTS, INFRARED-SPECTRUM, OXYGEN DIFLUORIDE, SF2, SPECTROSCOPY, SULFUR DIFLUORIDE}, isbn = {0021-9606}, url = {://A1997WV76300014}, author = {Gatehouse, B. and Muller, H. S. P. and Gerry, M. C. L.} } @article {2989, title = {{LOCAL-DENSITY CALCULATIONS OF STATIC DIELECTRIC-PROPERTIES OF CH4-NCLN}, journal = {Chemical Physics Letters}, volume = {217}, number = {5-6}, year = {1994}, note = {ISI Document Delivery No.: MV301Times Cited: 19Cited Reference Count: 36}, month = {Jan}, pages = {539-543}, type = {Article}, abstract = {{The dipole moments, dipole polarizabilities, and static hyperpolarizabilities of methane and the chloromethanes have been studied at the experimental geometry with the deMon density functional program. Using the local density approximation and large basis sets, we computed the dipole moments of CH4-nCln}, keywords = {BASIS-SETS, DIPOLE, FUNCTIONAL, HALOGENATED METHANES, HYPERPOLARIZABILITIES, IMPERFECT GASES, METHODS, MOLECULES, MOMENT DERIVATIVES, NONLINEAR OPTICAL-PROPERTIES, POLARIZABILITIES, PRESSURE VIRIAL-COEFFICIENTS}, isbn = {0009-2614}, url = {://A1994MV30100011}, author = {Chong, D. P.} }