THE FIRST STRUCTURALLY AUTHENTICATED COMPOUND CONTAINING A BOND BETWEEN DIVALENT TIN AND TETRAVALENT TIN

The reaction of 1 equiv of [Li(thf)(3) . Sn-(SiMe3)(3)] (1) with [Sn(2 -{(Me3Si)(2)C}-C5H4N)Cl] in Et2O at ambient temperature affords the co rresponding divalent Sn-tetravaLent Sn compound, [Sn(2-{(Me3Si)(2)C}-C 5H4N){Sn(SiMe3)(3)}] (2) in high yield. A single-crystal X-ray diffrac tion study reveals 2 to be monomeric and the divalent Sn-tetravalent S n bond to be 2.8689(5) Angstrom; this is the first measurement of such a bond. The Sn-119-(H-1) NMR spectrum exhibits two singlet resonances at delta 897 and -502, each with well-resolved, isotopically, shifted , Sn-119 and Sn-117 satellites (ca. 6700 and ca. 6400 Hz, respectively ); this is the first measurement of (1)J coupling between Sit atoms of different valence.