REACTIONS OF 1,2,3,4,5-TETRACHALCOGENASTANNOLANES WITH GROUP-6 AND GROUP-8 TRANSITION-METAL CARBONYLS - FORMATION OF NOVEL TRANSITION-METALCOMPLEXES BRIDGED BY STANNANETHIONES AND STANNANESELONES

The reactions of the 1,2,3,4,5-tetrachalcogenastannolanes Tb(Tip)SnY4 (1: 1a, Y = S; 1b, Y = Se) with W(CO)(5).THF and M(3)(CO)(12) (M = Ru, Os) are reported. Stannolane 1a reacted with W(CO)5.THF to produce Tb (Tip)SnS4.W(CO)(5) (2) in 40% yield, which was analyzed crystallograph ically. The structure of 2 contains an octahedral tungsten unit, the T HF Ligand of W(CO)(5).THF being replaced by a tetrathiastannolane ring at a position beta to tin. While triruthenium complexes (mu(3)-Y)(3)( mu(2)-Y)Ru-3(CO)(7)[Tb(Tip)Sn] (4: 4a, Y = S; 4b, Y = Se) and diruthen ium complexes (mu(3)-Y)(2)Ru-2(CO)(6)[Tb(Tip)Sn] (5: 5a, Y = S; 5b, Y = Se) were isolated from the reaction of 1 with Ru-3(CO)(12), the reac tions of 1 with Os-3(CO)(12) afforded triosmium complexes (mu(3)-Y)(3) Os-3(CO)(7)[Tb(Tip)Sn] (8: Y = S, Se) together with triosmium complexe s (mu(3)-Y)(3)(mu(2)-Y)Os-3(Co)(7)[Tb(Tip)Sn] (9a, Y = S) and diosmium complexes (mu(3)-Y)(2)Os-2(CO)(6)[Tb(Tip)Sn] (10, Y = S, Se), The str uctures of 4b, 5a, and 8 were characterized crystallographically. The isolation of 5 and 10, which have interesting and strained quadracycli c SnY(2)M(2) (M = Ru, Os) ring systems,was considered to be due to ste ric protection against polymerization by bulky Tb and Tip ligands. The complexes 4 and 9 contain three triply bridging chalcogen ligands in a cluster of three ruthenium or osmium atoms which have only one Ru-Ru or Os-Os bond. The complexes 8 are regarded as binuclear osmium compl exes bridged by a stannanethione and a stannaneselone, though the bond lengths between tin and chalcogen were elongated to those for single bonds and the angles around the tin atom were slightly spread out on a ccount of the complexation of osmium. The possible reaction mechanism is also proposed.