Spectroscopy and triplet photophysical properties of poly[N-((vinyloxy)carbonyl)carbazole] and its monomeric analog

Abstract

The triplet photophysical properties of poly[7V-((vinyloxy)carbonyl)carbazole] (PFCZ) and of its monomeric model iV-carbethoxycarbazole (MFCZ) have been investigated and compared with those of the widely studied poly(JV-vinylcarbazole) (PVCA). Two distinct triplet excimeric emissions are observed in solid films of PFCZ. Phosphorescence spectra of PFCZ and MFCZ in rigid solutions are essentially the same as observed previously for PVCA and JV-alkylcarbazoles, respectively. The fluorescence spectrum of PFCZ is significantly blue shifted relative to PVCA and, unlike PVCA, yields a structured emission both in solution and in the solid film state. In frozen solutions at 77 K spectral shifts of Os-saturated vs. N2-saturated solutions indicate the presence of a weakly bound singlet excimer. Phosphorescence lifetimes of PFCZ and MFCZ in rigid media are 6.2 and 7.0 s, respectively. The delayed fluorescence lifetime in solid films of PFCZ at 77 K is 3.5 s. The intensity of delayed fluorescence from PFCZ both in rigid solutions and in solid films depends upon the square of the excitation intensity and is thus thought to arise from triplet-triplet annihilation.

Carbazole based polymers as hosts for blue iridium emitters: synthesis, photophysics and high efficiency PLEDs

“…These slight differences could be explained by different overlaps of carbazole rings in lms due to different moieties and differently constrained steric environment. This can readily be appreciated by comparing excimer formation studies performed by Burkhart et al on poly[N-((vinyloxy)carbonyl)carbazole]24 and by Rippen et al on poly(N-vinyl carbazole) 19.…”

Effect of Pressure and Radiation on the Luminescent Properties of Poly(vinylbenzophenone−styrene)

“…They have been observed, e.g., in poly(vinylcarbazole) and in poly(vinylnapthalene). [14][15][16][17][18] In an extensive set of experiments O'Connor et al 19,20 studied fluorescence yields for copolymers of styrene with two aromatic molecules as a function of copolymer concentration and temperature. The most significant results were quenching of the styrene monomer and excimer emission by energy migration to the quenching molecule as well as Fo ¨rster radiationless energy transfer.…”

An investigation of binding energies of triplet excimers in carbazolyl-containing polymers

“…Phosphorescence spectra of PFCZ as a pure solid film at various temperatures. A delay time of 50 ms was used: (A) 15 K, (B) 25 K, (C) 40 K, (D) 94 K.…”