Functionalizable Polycyclic Aromatics through Oxidative Cyclization of Pendant Thiophenes.

TitleFunctionalizable Polycyclic Aromatics through Oxidative Cyclization of Pendant Thiophenes.
Publication TypeJournal Article
Year of Publication2002
AuthorsTovar, JD, Rose, A, Swager, TM
JournalJournal of the American Chemical Society
Keywordsarom polythiophene prepn elec current fluorescence decay, oxidative cyclization thiophene contg monomer prepn

We present a general strategy for obtaining large sulfur-contg. polycyclic aroms. from thienyl precursors through iron(III) chloride mediated oxidative cyclizations. By placing thienyl moieties in close proximity to adjacent arenes, we have directed the oxidized intermediates into controlled cyclization pathways, effectively suppressing polymer formation. Utilizing these cyclized compds. and their thienyl precursors, we have studied cyclization/polymn. pathways of polymers such as poly(2). The unsubstituted positions $\alpha$ to the sulfur atoms within these arom. cores allowed for efficient halogenation and further functionalization. As a demonstration, we prepd. a series of arylene-ethynylene polymers with varying degrees of chromophore aromatization and used them to probe the effects of synthetically imposed rigidity on polymer photophys. behavior. The symmetries and effective conjugation pathways within the monomers play a key role in detg. photophys. properties. We obsd. that rigid, aromatized chromophores generally led to increased excited-state lifetimes by decreasing radiative rates of fluorescence decay. [on SciFinder(R)]