Oxidative Addition of Diphenyldichalcogenides PhEEPh (E = S, Se, Te) to Low-Valent CN- and NCN-Chelated Organoantimony and Organobismuth Compounds

The reactions of the organoantimony(I) compound L1 4Sb4 (1) (where L1 = [o-C6H4(CHNC6H3(i-Pr)2-2,6)]) with diphenyldichalcogenides PhEEPh (E = S, Se, or Te) gave compounds L1Sb(EPh)2 (E = S (2), Se (3), Te (4)) as the result of the oxidative addition of the antimony(I) atom across the chalcogen–chalcogen bond. The reaction of diphenyldichalcogenides PhEEPh with an in situ prepared organobismuth(I) compound (via reaction of the parent chloride L1BiCl2 (5) with two equivalents of K[B(s-Bu)3H]) gave surprisingly diorganobismuth compounds L1 2Bi(EPh) (E = S (6), Se (7), Te (8)) as the major products along with only a trace amount of the intended compounds L1Bi(EPh)2 (E = S (9), Se (10), Te (11)). It turned out that this is the result of instability of 9–11 in solution, and their decomposition provided compounds 6–8. The bismuth compounds containing the pincer-type ligand L2 (L2 = [o,o-C6H3(CH2NMe2)2]) containing an extra donor pendant arm were studied with the aim to support their stability by an additional N→Bi interaction. Thus, in situ preparation of the organobismuth(I) compound from L2BiCl2 (12) and two equivalents of K[B(s-Bu)3H] followed by the addition of PhEEPh gave compounds L2Bi(EPh)2 (E = S (13), Se (14), Te (15)). Compounds 13–15 showed no tendency for redistribution reaction, contrary to 9–11, due to the rigid coordination of both nitrogen donor atoms of the ligand L2 to the bismuth atom. All studied compounds were characterized by the help of 1H and 13C NMR spectroscopy, by elemental analysis, and except compounds 4, 14, and 15 by single-crystal X-ray diffraction analyses.