by  M. Galimova, E. Zueva, A. Dobrynin, I. Kolesnikov, R. Musin, E. Musina A. Karasik

Dalton Trans., 2021,50, 13421-13429

doi: 10.1039/D1DT02344F

Two luminescent Cu4I4-cubane tetramers with N-methyl-10-(p-halogenophenyl)-5,10-dihydrophenarsazine ligands were synthesized and characterized by NMR spectroscopy, mass spectrometry, elemental analysis, and single-crystal X-ray diffraction analysis. The UV–Vis absorption and emission properties were studied and rationalized by DFT and time-dependent DFT calculations. The luminescence behavior was found to be rather different from that of recently reported tetranuclear copper iodide cubane clusters based on As,O-analogues – 10-(aryl)phenoxarsines. The crystalline powders of both complexes exhibit the temperature-dependent dual-band emission: the low-energy emission originates from the cluster-centered (3CC) triplet state, whereas the high-energy emission was attributed to the intraligand (3IL) triplet state.