Main group metal 1,3-dithiole-2-thione-4,5-dithiolate (DMIT) compounds: II. Synthesis and structures of tetrabutylammonium butyl- and phenyl-bis(1,3-dithiole-2-thione-4,5-dithiolato)stannates, [Bu 4N][RSn(DMIT) 2] (R  Bu or Ph)

Abstract

Structures have been determined for [BU 4N][RSn(DMIT) 2] (III; R  Bu and IV; R = Ph), obtained from [Bu 4N] 2[Zn(DMIT) 2] and RSnCl 3. These complexes are isostructural. In the spirocyclic anions, the tin atoms are pentacoordinate and have geometries between trigonal bipyramidal (TBP) and rectangular pyramidal: the distortions away from TBP geometry are calculated to be ca 48 and 70% for II and IV respectively. The S atoms in the chelate ligands form the quasi-basal planes with the R groups in axial sites. The DMIT ligands, while individually planar, are not coplanar: the angles between the DMIT mean planes are 19.2 and 10.8° for III and IV respectively. The anions are packed side by side in the c direction with S … S separations close to the sum of the van der Waals radii. In the a and b directions, there are arrays of alternating cation and anion units.