Structure and conformations of 1,1,1-trifluoromethanesulfenylamine, CF3SNH2. Gas electron diffraction, microwave spectroscopy and theoretical calculations

The geometric structure and the conformational composition of 1,1,1-trifluo romethanesulfenylamine, CF3SNH2, were investigated by gas electron diffract ion (GED) and microwave spectroscopy (MW). In the MW spectra transitions of two conformers were observed. Rotational constants of deuterated species d emonstrated that the more intense transitions belong to the anti form (nitr ogen lone pair antiperiplanar to S-C bond). From relative intensities and d ipole moments an energy difference Delta E = E(syn) - E(anti) = 1.1(1) kcal mol(-1) was derived. A joint analysis of GED and MW data resulted in the f ollowing skeletal parameters (r(z) values with 2 sigma uncertainties): S-N = 1.673(5) Angstrom, S-C = 1.836(5) Angstrom and C-S-N = 101.8(8)degrees. T hese parameters and the energy difference are well reproduced by B3PW91/6-3 1G* calculations. (C) 1999 Elsevier Science B.V. All rights reserved.