Luminescent monomer of substituted tetrastyrylpyrene and poly(p-phenylenevinylene) derivative with pyrene segments: Synthesis and photophysics

1,3,6,8-Tetrabromopyrene reacted with 1-tert-butyl-4-vinylbenzene to afford the luminescent monomer M. In addition, the reaction of 1,6-dibromopyrene with 1,4-didodecyloxy-2,5-divinylbenzene yielded a poly(p-phenylenevinylene) (PPV) derivative P. M dissolved partially in chloroform and completely in THF. P showed an excellent solubility being readily soluble in common organic solvents. M emitted intense blue-green light in THF solution with photoluminescence (PL) maximum at 507 nm and green-yellow light in thin film with PL maximum at 570 nm. Polymer P displayed in THF a PL maximum at 464 nm and a shoulder at 513 nm. Thin film of this polymer exhibited PL maximum at 572 nm. Both M and P emitted from excimers in solid state. The PL emission quantum yields in THF were 0.35 for M and 0.32 for P. The emission maximum of M thin film was red shifted by 9 nm after annealing at 150 °C for 24 h as a result of conformational changes of the molecules with increase in temperature.