Structural and spectroscopic characterization of CIC(O)SNSO. A theoreticaland experimental study

N-(Sulfinylimine)chlorocarbonylsulfane, CIC(O)SNSO, was prepared by the rea ction of CIC(O)SCI with Hg(NSO)(2). The crystal structure of CIC(O)SNSO was determined by X-ray diffraction analysis from crystals obtained at low tem perature using a miniature zone melting procedure. The molecule exhibits on ly one form with C-s symmetry: the C=O double bond syn with respect to the S-N single bond, the C-S single bond anti to the N=S double bond and the S- N single bond syn with respect to the S=O double bond. The following skelet al parameters were determined (distances in Angstrom, angles in degrees, er rors between parentheses expressed as sigma): Cl-C = 1.771(2), C=O = 1.184( 3), C-S = 1.750(2), S-N = 1.666(2), N=S = 1.534(2), S=O = 1.455(2), ClCO = 122.9(2), ClCS = 107.1(1), OCS = 130.0(2), CSN = 97.4(1), SNS = 122.3(1). N SO = 118.0(1), OCSN = -1.9, ClCSN = 178.0, CSNS = -178.0, SNSO = -1.2. Thes e experimental parameters compare satisfactorily with those obtained by ab initio and DFT calculations. The best agreement was found with the B3PW91/6 -31+G* calculation. These quantum chemical methods were also employed to pr edict the vibrational spectra providing a good agreement with the experimen tal Raman spectra measured from the liquid sample. It is shown that the ana lysis of the vibrational spectra provides a sound basis for the determinati on of the conformation and configuration of R-N=S=O compounds. Raman excita tion profiles were determined in the range from 514 to 413 nm. Most of the modes are predominantly enhanced via the pi --> pi* transition at 296 nm bu t additional intensity is derived from low-electronic transitions at ca. 45 0 and 430 nm which are too weak to be detectable in the UV/VIS absorption s pectra.