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 = t Bu ( a ), t Oct ( b )], react with bis(amino)stannylenes such as 1,3‐di‐ tert ‐butyl‐4,4‐dimethyl‐1,3,4,2λ 2 ‐diazasilastannetidine ( 2 ), 1,3‐di‐ tert ‐butyl‐4,4,5,5‐tetramethyl‐1,3,4,5,2λ 2 ‐diazadisila‐stannolidine ( 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(amino)stannylene and a four‐membered 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 cyclic stannylene 2 , two equivalents of 2 may also react with 1 a to a polycyclic 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 ring with close SnSe contacts. All products were characterized by multinuclear magnetic resonance spectroscopy ( 1 H, 13 C, 15 N, 29 Si, 77 Se, 119 Sn NMR) in solution, and the molecular structure of the polycyclic compound 10 was determined by single crystal X‐ray analysis [monoclinic; space group C2/c; a = 3 294.1(3), b = 1 321.5(3), c = 1 855.9(2) pm and β = 98.02(2)°].