New Spiro-Tin Compounds: Reaction of N,N'-Dialkyl Sulfur Diimides with Cyclic Bis(amino)stannylenes - Unexpected Formation of a N-N Bond

Z. Naturforsch. 50 b, 1811-1817(1995); received March 17, 1995 Sulfur Diimides, Bis(amino)stannylenes, Redox Reactions, Spiro-Tin Compounds, X-Ray N,N'-Dialkyl sulfur diimides (1), R(NSN)R [R = Me (a), Et (b), "Pr (c), "Bu (d)] react with cyclic bis(amino)stannylenes such as l,3-di-ter/-butyl-4,4-dimethyl-1,3,4,2A2-diazasilastannetedine (2) or l,3-di-terr-butyl-4,4,5,5-tetramethyl-l,3,4,5,2A2-diazadisilastannolidine (3) in a 2:1 ratio to give the new spiro-tin(IV) compounds 5a-d, 6b and 6c, built from the respective cyclic bis(amino)stannylene and a seven-membered ring in which the two sulfur diimide groups are coupled via a N-N bond and across the tin atom. A 1:1 adduct 4 is proposed as an intermediate which is the final product 4e in the case of R = 'Bu (le). The products were characterized by multinuclear magnetic resonance ('H, 13C, i5N, 29Si, ll9Sn NMR), and in the case of 5c the molecular structure was determined by single crystal X-ray structure analysis [monoclinic, space group C2/c ; a = 1504.1(3), b = 1393.3(3), c = 1688.6(3) pm; ß = 115.71(3)°].