SYNTHESIS AND CRYSTAL-STRUCTURE OF [SE3N2 CL]-(SBCL6)

[Se3N2Cl]+SbCl6- has been prepared as red crystals by the reaction of the nitride chloride Se2NCl5 with antimony(III) chloride in dichlorome thane. It was characterized by a crystal structure determination. Spac e group P1, Z = 2, 4396 observed unique reflections, R = 0.030. Lattic e dimensions at -80 degrees C: a = 698.2, b = 699.7, c = 1510.5 pm, a = 89.45 degrees, beta = 86.180, gamma = 68.22 degrees. The structure c onsists of two symmetry-independent cations and two symmetry independe nt anions, which differ only slightly from each other. The cations con tain Se3N2 five-membered rings, which deviate very little from planari ty as shown by folding angles of 14 degrees and 18 degrees. The Se-N b ond distances are between 171.4 and 176.4 pm suggesting double-bond co nstituents.