Synthesis of main-chain metallo-copolymers containing donor and acceptor bis-terpyridyl ligands for photovoltaic applications.

Two random (Zn(II)-based P1-P2) and two alternating (Ru(II)-based P3-P4) metallo-copolymers containing bis-terpyridyl ligands with various central donor (i.e., fluorene or carbazole) and acceptor (i.e., benzothiadiazole) moieties were synthesized. The effects of electron donor-acceptor interactions with metal (Zn(II) and Ru(II)) ions on their thermal, optical, and electrochemical properties were investigated. Because of the strong ICT transitions between donor and acceptor ligands in both Zn(II)- and Ru(II)-based metallo-coplymers and MLCT transitions in Ru(II)-based metallo-coplymers, the absorption spectra covered a broad range of 260-750 nm with the band gaps of 1.57-1.77 eV. In addition, the introduction of Ru(II)-based metallo-coplymer P4 mixed with PC(60)BM as an active layer of the BHJ solar cell device exhibited the highest PCE value up to 0.90%.

Novel reversible chemosensory material based on conjugated side-chain polymer containing fluorescent pyridyl receptor pendants.

A novel light-emitting monomer M1 and its side-chain polymer P1 containing three conjugated aromatic pendants, including one pyridyl terminus, were successfully synthesized via Wittig and Pd-catalyzed Heck coupling reactions. The fluorescence of polymer P1 was efficiently quenched upon addition of different metal ions due to the facile energy transfers from the pendent groups of polymer P1 to specific metal ions. Among these metal ions, P1 exhibited extraordinary sensory selectivities for Ni(2+) and Cu(2+) ions over the other metal ions due to the stronger binding capabilities of Ni(2+) and Cu(2+) ions with polymer P1. From the time-resolved fluorescence (TRF) signals in photoluminescence spectra, the emergences of τ(1) decay components in polymer complexes (P1+Ni(2+)) and (P1+Cu(2+)) clearly indicated that their TRF traces consisted of two contributions, one from the complexes (τ(1)) and the other from free polymer P1 (τ(2)). Upon addition of Ni(2+) and Cu(2+) ions, polymer P1 showed faster decay time constants (τ(1)) of metal ion quenching on TRF signals (i.e., better quenching efficiencies on photoluminescence) than its monomer M1. Furthermore, the on-off-on fluorescent switching behavior by adding a tridentate ligand 1,1,4,7,7-pentamethyldiethylenetriamine (PMDTA) to the polymer complex (P1+Cu(2+)) for several successive cycles demonstrated a superior reusable chemosensor of P1 for further applications.