Principles of the Construction of Polymer Structures, Heteronuclear (13C, 15N) CP-MAS NMR, and Thermal Behavior of Heteroleptic Bismuth(III) Complexes of the General Composition [Bi(S2CNR2)2X] (X = NO3, Cl)

Abstract

The crystalline heteroleptic bismuth(III) complexes, [Bi{S₂CN(iso-C₄H₉)₂}₂(NO₃)] (I) and [Bi{S₂CN(C₃H₇)₂}₂Cl] (II), are isolated in preparative yields. Both compounds form 1D polymer structures and are characterized by X-ray diffraction analysis (CIF files CCDC nos. 1877115 (I) and 1876364 (II)) and (¹³C, ¹⁵N) CP-MAS NMR spectroscopy. The coordination mode of each of the dialkyldithiocarbamate ligands is S,S′-anisobidentately terminal. The inorganic anions performing the μ₂-bridging function participate in the binding of the adjacent metallic atoms to form zigzag polymer chains. A new mode of bismuth(III) binding involving all oxygen atoms (O,O'-anisobidentate coordination to each adjacent bismuth atom) is found for the bridging nitrate groups in compound I. The bismuth atoms in the studied compounds are characterized by the eightfold [BiS₄O₄] (I) or sixfold [BiS₄Cl₂] (II) environment. The thermal behavior of the synthesized complexes is characterized by the data of simultaneous thermal analysis, using parallel recording of thermogravimetry and differential scanning calorimetry curves. In both cases, Bi₂S₃ is the only final product of the thermal transformations of compounds I and II.