REACTION OF N,N'-DIALKYL SELENIUM DIIMIDES WITH BIS(AMINO)STANNYLENES- FORMATION OF A TIN-TIN BOND

N,N'-Dialkyl selenium diimides 1, R(NSeN)R [R = tBu (a), tOct (b)], re act with bis(amino)stannylenes such as 1,3-di-tert-butyl-4,4-dimethyl- 1,3,4,2 lambda(2)-diazasilastannetidine (2), 1,3-di-tert-butyl-4,4,5,5 -tetramethyl-1,3,4,5,2 lambda(2)-diazadisilastannolidine (3), bis[tert -butyl(trimethylsilyl)amino]stannylene (4) and bis[bis(trimethylsilyl) amino]stannylene (5) in a 1:1 ratio. The products are either the spiro -tin(IV) compounds 6 and 7, consisting of the respective cyclic bis(am ino)stannylene and a four-membered SnNSeN ring, or the analogous four- membered 1,2,4,3-selenadiazastannetidine rings 8 and 9 with the amino groups linked to the tin atom. Only in the case of the four-membered c yclic stannylene 2, two equivalents of 2 may also react with la to a p olycyclic compound 10: Two molecules of 2 are linked by a tin-tin bond and this bond is bridged by the NSeN group, to give a five-membered S nNSeNSn ring with close Sn-Se contacts. All products were characterize d by multinuclear magnetic resonance spectroscopy (H-1, C-13, N-15, Si -29, Se-77, Sn-119 NMR) in solution, and the molecular structure of th e polycyclic compound 10 was determined by single crystal X-ray analys is [monoclinic; space group C2/c; a = 3294.1(3), b = 1321.5(3), c = 18 55.9(2) pm and beta = 98.02(2)degrees].