Photophysical studies of copolymers of N‐vinylcarbazole

Abstract

ABSTRACT:The absorption, fluorescence excitation and emission spectroscopy, and time-dependent spectrofluorimetry have been used to study the photophysics of copolymers of N-vinylcarbazole with different monomers like vinyl acetate, methyl acrylate, methyl methacrylate, butyl acrylate, and butyl methacrylate in dichloromethane. In all the copolymers and at different N-vinylcarbazole content, the absorption spectra reflect only the monomer carbazole units. The two kinds of excited monomer species of N-vinylcarbazole are present in S 1 state. Short-lived (ϳ3 ns) excited monomer decays forming low energy excimer obtained by the complete overlap of the excited carbazole monomer. The long-lived excited monomer (ϳ8 ns) decays to ground state without formation of any excimer. The high energy excimer is relatively short-lived and is formed by the partial overlap of the carbazole units. The presence of bulky group in the copolymer chain hinders the formation of excimers.

Characterization of the excimers of poly(N-vinylcarbazole) using TRANES

“…The polymer has been excited at three different wavelengths 280, 300 and 330 nm and consistent with the literature, no variation in the fluorescence decay pattern could be observed [19,22,35]. This reveals that only a single species is excited from the ground state and corroborates the steady state results.…”

“…2). This confirms that in the ground state there is a single species only and implies the formation of the dimers exclusively in the photoexcited state [35,36].…”

“…3 depicts, at sufficiently longer wavelengths the decay profile approaches towards a mono-exponential decay pattern corresponding to the long lifetime component. This variation in the decay profile on varying the emission wavelength signifies the fact that at higher energy region the short lifetime component is prominent while at lower energy the longer lived component is the dominating one [35].…”

“…Since the concentrations of the solutions are very low, possibility of formation of intermolecular excimer is ruled out. Literature suggests that the emission at higher energy side comes from the partially overlapped excimer while the other one in the lower energy side originates from the sandwich excimer [19,20,[34][35][36]. We have resolved the fluorescence spectra of PNVC both in toluene and water to get the spectral pattern and peak positions of the fluorescences of the individual excimers in solution.…”

Fluorescent Porous Carbazole‐Decorated Copolymer Monodisperse Microspheres: Facile synthesis, Selective and Recyclable Detection of Iron (III) in Aqueous Medium

“…Carbazole and its derivatives, which possess desirable photoconductivity,p hotosensitive, luminescence and hole-transporting properties, [15][16][17] have been developed as electronic materials and organic dyes for organic light-emitting diodes and photovoltaic cell. [18,19] Additionally,t he polar nitrogen-rich feature enablec arbazole as an ovel building block for the construction of porousf rameworkst argeted for gas selective separation and capturee xtensively.…”