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

Four complexes resulting from the interaction of SbCl5 and dmit (dmit = 1,3-dimethyl-2(3H)- imidazolethione) are synthesized and characterized. Previously reported SbCl5dmit (I) is shown to be the dithiouronium disulfide (dmit22+) salt of [Sb2Cl10]2−. Refluxing I in CH3CN yielded [dmit2] [SbCl4]2 (II) while refluxing I in dimethylformamide yielded a salt containing a unique dithiouronium monosulfide dication in combination with [SbCl6]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 [Sb2Cl10]2− anion made up of zigzag chains of SbCl6 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 P21/c; Z = 4; a = 16.25(1), b = 12.94(1), c = 11.93(1) Å, β = 99.47°; V = 2474 Å3; Dc = 2.103 g/cm3, Do = 2.09 g/cm3 (flotation in CH2I2/C2H2Cl4). III: space group Cmcm; Z = 8; a = 17.56(1), b = 29.15(1), c = 12.65(1) Å; V = 6475 Å3; Dc = 1.606 g/cm3, Do = 1.59 g/cm3 (flotation in CH2Cl2/CH2I2/C2H2Cl4). 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 Å3; Dc 1.476 g/cm3, Do indeterminate.