Conversion of poly(1,3-dihydroisothianaphthene) into polyisothianaphthene with the new dehydrogenation agent, tert-butyl hypochlorite

The low band-gap conducting polymer, polyisothianaphthene (PITN), which is usually considered to be insoluble and cannot be processed into film, is prepared by dehydrogenation from its precursor polymer, poly(1,3-dihydroisothianaphthene) (PDHITN), in solution with the use of the new dehydrogenation agent, tert-butyl hypochlorite (tBHC), and pyridine as terminating and stabilizing agent. The PITN solution obtained is stable and a uniform PITN film can be obtained from it by casting. The resulting PITN film has less defects as reflected in its high optical absorption wavelength (λmax = 810 nm) and has good electrochromic property.