Crystal structure of iodobis-(NN-diethyldithiocarbamato)iron(III)

Abstract

The crystal and molecular structure of the title compound has been determined by single-crystal X-ray diffraction methods. Solution of the structure by conventional heavy-atom Patterson and Fourier methods followed by block-diagonal least-squares refinement has resulted in a final conventional R value of 0·11 for 567 visually estimated independent observed reflections. The compounds crystallizes in the monoclinic system, space group P21/n with Z= 4, a= 11·65 ± 0·02, b= 17·38 ± 0·03, c= 9·34 ± 0·02 Å, and = 104·2 ± 0·2°. The structure is similar to that of the chloro-analogue, [FeCl(CS2·NEt2)2], the co-ordination about the iron atom being an approximate square pyramid consistent with the observed spin state of S. The iodine atom is at the apex of the pyramid, and the iron atom at its centre lies 0·6 Å above the basal plane of the four S atoms of the dithiocarbamate ligands, the iron atom being substantially coplanar with each of these. The four Fe–S distances [2·28(2)Å] are comparable with those of the chloro-analogue [2·30(1)Å] and the intraligand dimensions are normal for a bidentate dithiocarbamate [S–Fe–S 76(1), S–C–S 108(2)° C–S 1·73(4), and C–N 1·37(8)Å]. The Fe–I bond [2·59(1)Å] is an unusual example of an iron(III)–iodine(–I) linkage.