About a new class of inorganic polymers:: the polythiocyanogens [Sz(CN)2]x

It is shown that all the pseudohalogens belonging to the series of sulfur dicyanide S-y (CN)(2) or thiocyanogens polymerise very easily in the dry state, under moderate heating to produce a series of brick-red or orange solids known as polythiocyanogens with the general formula [S-y(CN)(2)](x) with y an integer 1, 2, 3, 4. It is shown by FT-IR, electronic spectroscopy, and C-13 NMR spectroscopy that the structure of all the series is essentially the same. The use of model compounds with 1,3,5-triazine structure and of particular reactions with Na2S and NaCN reveal that the [S-y(CN)(2)](x) polymers have essentially a polyazomethine chain analogous to that of polycyanogen or paracyanogen (CN), but crosslinked with sulfur bridges of different length depending on the sulfur chain length in the original monomer. (C) 2002 Elsevier Science Ltd. All rights reserved.