Insertion reactions of CO2, OCS, and CS2 into the Sn–N bonds of (Me2N)2Sn: NMR and X-ray structural characterization of the products

The interactions of the heteroallenes CO2, OCS, and CS2 with (Me2N)2Sn have been investigated. These CX2 species insert into the Sn–N bonds under mild conditions to provide products bis-(N,N-dimethylcarbamato)tin(II), [(Me2NCO2)2Sn]2, bis-(N,N-dimethylthiocarbamato)tin(II), [Me2NC(O)S]2Sn and bis-(N,N-dimethyldithiocarbamato)tin(II), (Me2NCS2)2Sn. These molecules have been fully characterized by traditional spectroscopic methods as well as by X-ray crystallography. The [Me2NC(O)S]2Sn product is the first example of a structurally characterized Sn(II) thiocarbamate. The solid-state structures of the final products vary depending on the heteroallene inserted. The CO2-inserted product is dimeric in the solid-state, with both bridging and chelating carbamate ligands. These dimers form a chain-like network via intermolecular Sn⋯O interactions. The monomeric thiocarbamate also shows a chain-like extended structure, through both Sn⋯O and Sn⋯S interactions, while the dithiocarbamate product has no significant intermolecular contacts.