Anthracene-Triphenylamine-Based Platinum(II) Metallacages as Synthetic Light-Harvesting Assembly.

Two trigonal prismatic metallacages and bearing triphenylamine and anthracene moieties are designed and synthesized to fabricate artificial light-harvesting systems (LHSs). These two cages are prepared via the coordination-driven self-assembly of two anthracene-triphenylamine-based tripyridyl ligand , three dicarboxylates, and six 90° Pt(II) acceptors. The design of the anthracene-triphenylamine chromophore makes possible the tunable excited-state property (like the emissive transition energy and lifetime) as a function of the solvent polarity, temperature, and concentration. The synergistic photophysical footprint of these metallacages, defined by their high absorptivity and emission quantum yield (QY) relative to the free ligand , signifies them as a superior light sensitizer component in an LHS. In the presence of the fluorescent dye Nile Red (NR) as an energy acceptor, the metallacages display efficient (>93%) excited energy transfer to NR through an apparent static quenching mechanism in viscous dimethyl sulfoxide solvent.