Intramolecular Phosphacyclization: Polyaromatic Phosphonium P-Heterocycles with Wide-Tuning Optical Properties.

ABSTRACT: Rationally designed cationic phospha-polyaromatic fluorophores were prepared through intramolecular cyclization of the tertiary ortho-(acene)phenylene-phosphines mediated by Cu^II triflate. As a result of phosphorus quaternization, heterocyclic phosphonium salts 1 c-3 c, derived from naphthalene, phenanthrene, and anthracene cores, exhibited very intense blue to green fluorescence (Φ_em =0.38-0.99) and high photostability in aqueous medium. The structure-emission relationship was further investigated by tailoring the electron-donating functions to the anthracene moiety to give dyes 4 c-6 c with charge-transfer character. The latter significantly decreases the emission energy to reach near-IR region. Thus, the intramolecular phosphacyclization renders an ultra-wide tunin

SUBMITTER: Belyaev A 

PROVIDER: S-EPMC6594060 | biostudies-literature | 2019 May

REPOSITORIES: biostudies-literature