Functionalized organotin-chalcogenide complexes that exhibit defect heterocubane scaffolds: formation, synthesis, and characterization.

The synthesis of new functionalized organotin-chalcogenide complexes was achieved by systematic optimization of the reaction conditions. The structures of compounds [(R(1, 2) Sn)3 S4 Cl] (1, 2), [((R(2) Sn)2 SnS4 )2 (μ-S)2 ] (3), [(R(1, 2) Sn)3 Se4 ][SnCl3 ] (4, 5), and [Li(thf)n ][(R(3) Sn)(HR(3) Sn)2 Se4 Cl] (6), in which R(1) =CMe2 CH2 C(O)Me, R(2) =CMe2 CH2 C(NNH2 )Me, and R(3) =CH2 CH2 COO, are based on defect heterocubane scaffolds, as shown by X-ray diffraction, (119) Sn NMR spectroscopy, and ESI mass spectrometry analyses. Compounds 4, 5, and 6 constitute the first examples of defect heterocubane-type metal-chalcogenide complexes that are comprised of selenide ligands. Comprehensive DFT calculations prompted us to search for the formal intermediates [(R(1) SnCl2 )2 (μ-S)] (7) and [(R(1) SnCl)2 (μ-S)2 ] (8), which were isolated and helped to understand the stepwise formation of compounds 1-6.