||Effects of N-heteroaromatic ligands on highly luminescent mononuclear copper(I)-halide complexes
Ohara, Hiroki ,
Kobayashi, AtsushiKato, Masako
775 , 2015-07 , Elsevier
A series of mononuclear Cu(I)-halide complexes, [CuX(PPh3)(2)(L)] (X= CI-, Br-, I-; PPh3 = triphenylphosphine; L = pyridine (py), isoquinoline (iq), 1,6-naphthyridine (nap)), were synthesized. The emission color of [CuX(PPh3)2(L)] varies from blue to red by changing the L ligands and the halide ions, and all the complexes exhibit high emission quantum yields (0.16-0.99) in the crystals. The emission studies revealed that the emissive states of [CuX(PPh3)(2)(L)] differ depending on the L ligand. Complexes [CuX(PPh3)(2)(py)] and [CuX(PPh3)2(nap)] mainly emit from the singlet metal-to-ligand charge transfer mixed with the halide-to-ligand charge transfer ((1)(M + X)LCT) state at room temperature. In contrast, emissions from [CuX(PPh3)(2)(iq)] at room temperature originate from both (3)(M + X)LCT and (3)pi pi* states. These results indicate that N-heterodomatic ligands play an important role in the emission properties of mononuclear Cu(I)-halide complexes. (C) 2015 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved.