Main group metal halide complexes with sterically hindered thioureas. X. Complexes of antimony(V) chloride and 1,3-dimethyl-2(3H)-imidazolethione

Abstract

Four complexes resulting from the interaction of SbCl 5 and dmit (dmit = 1,3-dimethyl-2(3H)- imidazolethione) are synthesized and characterized. Previously reported SbCl 5dmit ( I) is shown to be the dithiouronium disulfide (dmit 2 2+) salt of [Sb 2Cl 10] 2−. Refluxing I in CH 3CN yielded [dmit 2] [SbCl 4] 2 ( II) while refluxing I in dimethylformamide yielded a salt containing a unique dithiouronium monosulfide dication in combination with [SbCl 6] 2− ( III). A fourth salt was characterized via X-ray crystallography in an attempt to determine the structure of I. Selection of a non-representative crystal revealed a new compound also containing the monosulfide dication observed in III but in combination with the [Sb 2Cl 10] 2− anion made up of zigzag chains of SbCl 6 octahedra sharing disordered Cl vertices and alternating Sb(III) and Sb(V) units with chlorine bridges trans to each other in the latter and cis in the former. Bulk quantities of IV could not be synthesized for further characterization. Crystallographic parameters were determined for II, III and IV, but only the structure of IV was solved. Crystallographic data for II: space group P2 1/ c; Z = 4; a = 16.25(1), b = 12.94(1), c = 11.93(1) Å, β = 99.47°; V = 2474 Å 3; D c = 2.103 g/cm 3, D o = 2.09 g/cm 3 (flotation in CH 2I 2/C 2H 2Cl 4). III: space group Cmcm; Z = 8; a = 17.56(1), b = 29.15(1), c = 12.65(1) Å; V = 6475 Å 3; D c = 1.606 g/cm 3, D o = 1.59 g/cm 3 (flotation in CH 2Cl 2/CH 2I 2/C 2H 2Cl 4). IV: space group C2/ c; Z = 4; a = 16.131(4), b = 12.161(3), c = 18.862(4) Å, β = 92.16°; V = 3697 Å 3; D c 1.476 g/cm 3, D o indeterminate.