Quenching in the excited singlet state of amphiphilic copolymers with pendant carbazolylalkyl groups in aqueous solution

Amphiphilic copolymers with pendant ­carbazolylalkyl groups. ­Effect of polymer structure on ­retardation of self‐quenching

“…Relative fluorescence quantum yields (Φ r ) were determined by comparing the area for the corrected spectra. The copolymerizations of AMPS and the present (meth)acrylamides gave highly random copolymers, as in the previous cases [1,4]. The results of polymerization for poly(CzEMAm-co-AMPS) [r-CzEMAm(x)], as a typical example, are shown in Table 1.…”

“…Figure 2 shows the fluorescence spectra of poly(CzMMAm-co-AMPS) [r-CzMMAm(x)] in DMF. As in the case of poly(CzPMAm-co-AMPS) [r-CzPMAm(x)] [1], all the copolymers showed a structured monomer emission which decayed exponentially [the lifetime (t) = 12.8 AE 0.5 nsec], indicating that this type of copolymers are free of excimer formation and self-quenching in DMF. The spectra of r-CzMMAm(x) and poly(CzMAAm-co-AMPS) [r-CzMAAm(x)], are essentially the same, were slightly broadened and blue-shifted by ca.…”

“…Copolymers of (meth)acrylamides with sodium 2-acrylamido-2-methylpropanesulfonate (AMPS) were prepared in N,N-dimethylformamide (DMF) by use of 2,2'-azobis(isobutyronitrile) at 60°C, according to our previous method [10]. Copolymers consisting of 3-(9-carbazolyl)propylmethacrylamide (CzPMAm) are those reported previously [1]. The content of Cz groups in the copolymer was determined by absorption spectroscopy in DMF using the corresponding homopolymers as standards.…”

“…As a part of our continuing interest in amphiphilic copolymers with aromatic chromophores, we have recently investigated fluorescence properties of methacrylamide-and methacrylate-type of polyanions with pendant carbazolyalkyl groups in aqueous solution [1]. The results demonstrated that hydrophobic aggregation of carbazolyl (Cz) chromophores causes`self-quenching', as observed for concentrated solutions of dyes [2], much less efficiently compared with the corresponding vinyltype of copolymers.…”

Highly Fluorescent Merocyanine and Cyanine PMMA Copolymers

“…At this point, we attribute the reduction of the quantum yield for copolymers with higher dye content to concentration quenching. This phenomenon was shown, for instance, by Itoh et al for copolymers containing dyes with known aggregation caused quenching behavior [53] where lower ratios of the incorporated dye minimize the quenching originating from intra-and intermolecular aggregation. For the cyanine-containing copolymers 6a-d, a maximum quantum yield of 13% for 6a was achieved ( Figures S37-S40, Supporting Information).…”