An investigation on the structure of polyselenocyanogen [Se2(CN)2]x

The structure of polyselenocyanogen [Se-2(CN)(2)](x) is analogous to that of polythiocyanogens, which have the general formula [S-y(CN)(2))](x) (y= 1, 2, 3,...). This result is based on the surprising fact that the FT-IR spectrum of the former compound is similar to the spectra of the latter class of compounds and on other experimental data. Thus, the proposed structure for polyselenocyanogen involves polyazomethine chains connected together by selenium bridges. Selenocyanogen Se-2(CN)(2) polymerizes when treated with certain organic solvents. The polymerization was followed by electronic spectroscopy and involves the formation of peculiar absorption bands in the visible and near infrared portion of the spectrum. Alternatively, selenocyanogen polymerization is promoted by thermal treatment in high boiling solvents like xylenes and decalin. The resulting polymer shows an FT-IR spectrum comparable to that of polythiocyanogens. The thermal stability of selenocyanogen has been studied by thermogravimetric analysis (TGA) in conjunction with differential thermal analysis (DTA). Heating of Se-2(CN)(2) under N-2 to 650 degreesC causes conversion into paracyanogen (CN)(x) with the release of selenium.