OPTICAL-PROPERTIES OF A NOVEL CARBON-CARBON CHAIN POLYMER WITH PENDENT POLY(THIOPHENE)S

The synthesis of a novel soluble carbon-carbon chain polymer with pend ent terthiophene groups, poly(5-vinyl-2,2':5',2''-terthiophene) (PVT), is described. The solvent-cast thin films of PVT display strong blue- green photoluminescence and, thus, PVT is expected to show electrolumi nescence in this region. The terthiophene side chains in PVT cross-lin k when the polymer is oxidized in solution or as thin films with FeCl3 or SbCl5. Based on model studies we have proposed that terthiophene r adical cations, initially generated upon doping, slowly couple with ne ighboring neutral species to yield the radical cations of sexithiophen e. The neutralization of the doped polymer with triethylamine yielded an insoluble, cross-linked material. The UV irradiation of thin films of PVT results in cross-linking and insolubilization of the polymer. T he mechanism of the photoinitiated cross-linking reaction is discussed .