The Reactions of Dihalogenoalkanes with Dimethyltin Bis-(N,N-dimethyldithiocarbamate) and Related Compounds

Dimethyltin-bis(N,N-dimethyldithiocarbamate), (CH3)2Sn[S2CN(CH3)2]2, reacts with dihalogenoalkanes to give 1,3-dithiacycloalkyl-2-dimethylimminium dimethyltin halides, (Remark: Graphics omitted.) (n=1 or 2; m=2, 3, or 4; X=Cl, Br, or I). On the other hand, the reactions between dimethyltin bis(N-methyl-N-phenyldithiocarbamate), (CH3)2Sn[S2CN(CH3)(C6H5)]2, and dihalogenoalkanes yield preferentially alkylene bis(N-methyl-N-phenyldithiocarbamate). The difference in reactivity between the two types of complexes is discussed. The infrared and NMR spectra indicate that the positive charge on the dithiacycloalkylimminium ions is more delocalized in the higher homologues. The configurations of dimethyltin trihalide and tetrahalide anions in the solid state and in solution are also presented on the basis of the infrared spectra; the results suggest that, in solution, dimethyltin trihalide anions are more likely to be formed than are dimethyltin tetrahalides.