Luminescent Cu(I) and Ag(I) coordination polymers: Fast phosphorescence or thermally activated delayed fluorescence

By applying two donor-acceptor motif molecules, 5,10-di(pyridin-4-yl)-5,10-dihydrophenazine (L1) and 10,10'-di(pyridin-3-yl)-10H,10'H-9,9'-spiroacridine (L2), as ligands and Cul/AgCF3CO2 as metal salt, we synthesized three coordination polymers, namely, {Cu-4)(L1)(2)l(4)) (CP1), (Cu(L2)I center dot CHCl3} (CP2) and {Ag(L2)CO2CF3 center dot CHCl3} (CP3). X-ray crystallographic analysis revealed that three coordination polymers all feature one-dimensional (1D) linear chains which are consisting of molecular boxlike units. In comparison with low photoluminescence quantum yield (PLQY) of two ligands, three coordination polymers, CP1, CP2 and CP3, present more intense photoluminescence with PLQY of 15%, 46% and 34% at room temperature respectively. The PL emission of CPI and CP2 at room temperature could be attributed to the fast phosphorescence with lifetime both around 5 mu s due to effective intersystem crossing (ISC). Whilst, it is worth noting that CP3 exhibit thermally activated delayed fluorescence (TADF) emission at room temperature. (C) 2019 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.