Structure and Dipole Moment for SF4

Abstract

The microwave spectrum and structure of sulfur tetrafluoride has been determined. One FSF angle is 101°33′±30′, the opposite FSF angle is 186°56′±30′. The bond length for the nearly linear bonds is 1.646 A±0.003 A; for the other pair it is 1.545 A±0.003 A. The dipole moment was determined from the Stark effect to be 0.632±0.003 debye.

Infrared Spectroscopy of the ν1 Band of Sulfur Tetrafluoride, SF4

“…Significant changes in the magnitude of the A rotational constant were accounted for by a second-order a-type Coriolis interaction between the ν 4 and ν 9 modes. More recently, we have also recorded the rotational spectrum of both 32 SF 4 and 34 SF 4 using pulsed-jet Fourier-transform microwave (FTMW) spectroscopy and derived precise spectroscopic parameters for each isotopomer (8) using the Watson A-reduced Hamiltonian (9), the results being consistent with those from the earlier studies (6,7). 1 To whom correspondence should be addressed.…”

“…1. Precise structural parameters for SF 4 were first determined by Tolles and Gwinn in 1961 from an analysis of the microwave spectra of 32 SF 4 and 34 SF 4 (6). The C 2ν symmetry of the ground vibrational state of the molecule was confirmed and the axial F-S-F angle determined to be 173.1 ± 0.5…”

The unit cells and space groups of SeCl4and TeCl4

“…In the gas phase the molecules are believed to have the structure shown in (I), with X-M-X" bond angles of approximately 90 ° and X'-M-X" angles of approximately 120 ° . This has been supported by electron diffraction studies of SF 4 (Kimura & Bauer, 1963;Ewing & Sutton, 1963), SeF 4 (Bowen, 1953 and TeC14 (Stevenson & Schomaker, 1940); microwave studies of SF 4 (Tolles & Gwinn, 1962); and the vibrational spectra of SF4 (Dodd, Woodward & Roberts, 1956). The liquid states of SF 4 and SeF4 have also been assigned this configuration on the basis of nuclear magnetic resonance spectra (Muetterties& Phillips, 1959;Cotton, George & Waugh, 1958).…”

Synthesis and Characterization of Tetramethylammonium Trifluorosulfate

“…The difference in S À F bond lengths of 10.6 pm is comparable to molecules, such as SF 4 , where differences between S À F eq and S À F ax of 10.1 pm have been observed. [35] Comparing molecules and isoelectronic molecules, the formal negative charges in anions clearly enhance the formation of semi-ionic, three-center four-electron bonds, thereby causing their unusual lengths.…”