SYNTHESIS OF POLY(ISOTHIANAPHTHENE) FROM 1,1,3,3-TETRACHLOROTHIOPHTHALAN AND TERT-BUTYLMERCAPTAN - MECHANISM AND QUANTITATIVE-ANALYSIS BY SOLID-STATE NMR

A new synthetic route to the low bandgap polymer poly(isothianaphthene ) (PITN) is presented. This new route comprises the reaction of 1,1,3, 3-tetrachlorothiophthalan with tert-butylmercaptan and trifluoroacetic acid as a catalyst. This reaction clarifies the mechanism proposed fo r the synthesis of PITN from phthalic anhydride and phosphorus pentasu lfide. The obtained product was analysed by elemental analysis, FTi.r. , FT Raman and solid state n.m.r, spectroscopy. Electrical conductivit y after synthesis equals approximately 10(-2) S cm(-1). All experiment al data are consistent with those of PITN obtained via other synthetic procedures. An indication of the number average molecular weight of P ITN is given by quantitative end group analysing using CP/MAS n.m.r. ( C) 1997 Elsevier Science Ltd.