The reaction of [(Me3Si)(2)N](2)S With an equimolar amount of SeCl4 in diox
ane at 50 degreesC affords [(Se2SN2)Cl](2) (1) in excellent yield. Crystals
of 1 are orthorhombic, space group Pbca, with a = 8.5721(7) Angstrom, b =
7.8336(6) Angstrom, c = 15.228(1) Angstrom, and Z = 8. The crystal structur
e contains two planar Se2SN2.+ rings which are linked by intermolecular Se.
..Se interactions [d(Se-Se) = 3.0690(7) Angstrom]. The EI mass spectrum sho
ws Se2SN2.+ as the fragment of highest mass. Both the N-14 and Se-77 NMR sp
ectra show a single resonance (-52 and 1394 ppm, respectively). The solid [
(Se2SN2)Cl](2) gives a strong ESR signal indicating the presence of a Se2SN
2.+ radical. The Raman spectrum was assigned through normal coordinate trea
tment involving a general valence force field. The vibrational analysis yie
lded a good agreement between the observed and calculated wavenumbers.