Synthesis and Properties of Thieno[2,3,4:4,5]naphtho[1,8-cd]pyridines

Thieno[2 ',3 ',4 ':4,5]naphtho[1,8-cd]pyridines, S,N-doped pyrene analogs, were prepared bycombinationof Pd catalyzed cross-coupling reactions and acid-mediated cycloisomerization.The modular scope of the synthesis allowed for access to a varietyof functionalized derivatives. The photophysical properties have beenstudied in detail by steady-state and femtosecond transient absorptionaccompanied by cyclic voltammetry and (TD)-DFT calculations. The introductionof a five-membered thiophene into the 2-azapyrene scaffold leads toredshifted emission and substantial effects on the excited state dynamics,e.g., quantum yield, lifetime, decay rates, and the ISC ability, whichcan be further tuned by the substitution pattern of the heterocyclicscaffold.