Isomeric Molecular Forms of Pseudo-Binuclear Bismuth(III) Dithiocarbamate [Bi2{S2CN(CH2)6}6]: Preparation, Thermal Behavior, and Structural Effect of Its Solvation with DMSO, [Bi2{S2CN(CH2)6}6]⋅2(CH3)2SO

Bismuth(III) hexamethylenedithiocarbamate (HmDtc) [Bi₂{S₂CN(CH₂)₆}₆] (I) and its solvated with dimethyl sulfoxide form [Bi₂(S₂CNHm)₆]⋅2(CH₃)₂SO (II) have been obtained. The crystal structure of compound I shows an unusual alternation of two unsymmetrical isomeric pseudo-binuclear [Bi^1/1B(HmDtc)₃···Bi^1A/1C(HmDtc)₃] molecules, each of which involves two non-equivalent mononuclear moieties combined by secondary Bi···S bonds. The solvation of complex I leads to the structural unification of isomeric [Bi(HmDtc)₃] molecules followed by their self-organization into centrosymmetric pseudo-dimers in the structure of compound II. All HmDtc ligands coordinate in S,S'-anisobidentate mode to form four isomeric (in I) or structurally unique [Bi(HmDtc)₃] molecules (in II), whose distorted polyhedra can be approximated by pentagonal pyramid or octahedron. Solvating DMSO molecules are retained in the structure II by C–H···O hydrogen bonds. The analysis of energy dispersive X-ray spectra allowed one to identify the residual matter obtained by thermolysis of the complexes as Bi₂S₃ with admixture of Bi⁰. [ABSTRACT FROM AUTHOR]