2-Methyl-4,5,6,7,8,9-hexahydrocycloocta[d][1,2,3]selenadiazol]-2-ium Iodide

The synthesis of the first 2-alkyl-1,2,3-selenadiazol-2-ium salt is reported. Extensive spectroscopic characterization including Se-NMR was performed and the results are compared with those of the known 3-ium isomer. The yellow compound crystallizes in blocks as well as in columns. The crystal structures of both types are solved by X-ray diffraction and give final proof of the molecular structure.