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

Organoantimony(III) and organobismuth(III) sulfides, containing O,C,O-chelating ligands (L 1−3 = 2,6-(ROCH 2 ) 2 C 6 H 3 −, where R = Me (L 1 ), t -Bu (L 2 ), or mesityl (L 3 )), [L 1−3 MS] 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 Na 2 S·9H 2 O in toluene/water. All sulfides 5 − 8 were characterized by elemental analysis, electrospray ionization mass spectrometry, 1 H and 13 C 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 °C but decomposes at ambient temperature. While the reaction of 5 and 7 with I 2 yielded the expected organoantimony iodides L 1,3 SbI 2 (L 1 ( 9 ), L 3 ( 10 )), compound 6 containing ligand L 2 gives the unexpected oxastibol 12 besides the intended diiodide L 2 SbI 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.