Synthesis, Structure, and Reactivity of Intramolecularly Coordinated Organoantimony and Organobismuth Sulfides

Organoantimony(III) and organobismuth(III) sulfides, containing O,C,O-chelating ligands (L1-3 = 2,6-(ROCH2)(2)C6H3-, where R = Me (L-1), t-Bu (L-2), or mesityl (L-3)), [L1-3MS](2), where M = Sb (L-1 (5), L-2 (6), L-3 (7)) or M = Bi (L-2 (8)), were prepared by the reaction of parent organoantimony and organobismuth chlorides with Na2S center dot 9H(2)O in toluene/water. All sulfides 5-8 were characterized by elemental analysis, electrospray ionization mass spectrometry, H-1 and C-13 NMR spectroscopy, and X-ray diffraction techniques. Organoantimony sulfides 5-7 are stable both in solution and in the solid state in contrast to the organobismuth congener, which is stable at -30 degrees C but decomposes at ambient temperature. While the reaction of 5 and 7 with I-2 yielded the expected organoantimony iodides (LSbI2)-Sb-1,3 (L-1 (9), L-3 (10)), compound 6 containing ligand L-2 gives the unexpected oxastibol 12 besides the intended diiodide (LSbI2)-Sb-2 (11). The molecular structure of 12 in the solid state was determined by X-ray diffraction techniques and showed formation of an Sb-O covalent bond as a result of C-O ether bond cleavage.