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 [((RSn)-Sn-1,2)(3)S4Cl] (1, 2), [(((RSn)-Sn-2)(2)SnS4)(2)(-S)(2)] (3), [((RSn)-Sn-1,2)(3)Se-4][SnCl3] (4, 5), and [Li(thf)(n)][((RSn)-Sn-3)((HRSn)-Sn-3)(2)Se4Cl] (6), in which R-1=CMe2CH2C(O)Me, R-2=CMe2CH2C(NNH2)Me, and R-3=CH2CH2COO, are based on defect heterocubane scaffolds, as shown by X-ray diffraction, (SnNMR)-Sn-119 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 [((RSnCl2)-Sn-1)(2)(-S)] (7) and [((RSnCl)-Sn-1)(2)(-S)(2)] (8), which were isolated and helped to understand the stepwise formation of compounds 1-6.