Reactivity of bis(2,2,5,5-tetramethyl-2,5-disila-1-azacyclopent-1-yl)tin with CO(2), OCS, and CS(2) and comparison to that of bis[bis(trimethylsilyl)amido]tin.

The heterocumulenes carbon dioxide (CO(2)), carbonyl sulfide (OCS), and carbon disulfide (CS(2)) were treated with bis(2,2,5,5-tetramethyl-2,5-disila-1-azacyclopent-1-yl)tin {(CH(2))Me(2)SiN}(2)Sn, an analogue of the well-studied bis[bis(trimethylsilyl)amido]tin species (Me(3)Si)(2)NSn, to yield an unexpectedly diverse product slate. Reaction of {(CH(2))Me(2)SiN}(2)Sn with CO(2) resulted in the formation of 2,2,5,5-tetramethyl-2,5-disila-1-oxacyclopentane, along with Sn(4)(μ(4)-O){μ(2)-O(2)CN[SiMe(2)(CH(2))(2)]}(4)(μ(2)-N═C═O)(2) as the primary organometallic Sn-containing product. The reaction of {(CH(2))Me(2)SiN}(2)Sn with CS(2) led to formal reduction of CS(2) to CS(2), yielding {(CH(2))Me(2)SiN}(2)SnCS(2){(CH(2))Me(2)SiN}(2)Sn, in which the CS(2) is coordinated through C and S to two tin centers. The product {(CH(2))Me(2)SiN}(2)SnCS(2){(CH(2))Me(2)SiN}(2)Sn also contains a novel 4-membered Sn-Sn-C-S ring, and exhibits a further bonding interaction through sulfur to a third Sn atom. Reaction of OCS with {(CH(2))Me(2)SiN}(2)Sn resulted in an insoluble polymeric material. In a comparison reaction, (Me(3)Si)(2)NSn was treated with OCS to yield Sn(4)(μ(4)-O)(μ(2)-OSiMe(3))(5)(η(1)-N═C═S). A combination of NMR and IR spectroscopy, mass spectrometry, and single crystal X-ray diffraction were used to characterize the products of each reaction. The oxygen atoms in the final products come from the facile cleavage of either CO(2) or OCS, depending on the reacting carbon dichalogenide.