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Herein, a series of ionic mononuclear Cu(I) complexes, [Cu(phen)(bdppmapy)]Cl (1a), [Cu(phen)(bdppmapy)]Br (2a), [Cu(phen)(bdppmapy)]I (3a), [Cu(phen)(bdppmapy)]SCN (4a), [Cu(Dpq)(bdppmapy)]Cl (1b), [Cu(Dpq)(bdppmapy)]Br (2b), [Cu(Dpq)(bdppmapy)]I (3b) and [Cu(Dpq)(bdppmapy)]SCN (4b) {phen = [1,10]phenanthroline; Dpq = pyrazino[2,3-f][1,10]-phenanthroline; bdppmapy = N,N-bis((diphenylphosphino)methyl)-2-pyridinamine} have been synthesized and characterized by using IR, NMR, elemental analysis, single crystal X-ray diffraction analysis, fluorescence spectroscopy methods, and UV-vis and terahertz (THz) time-domain absorption spectroscopy. Their crystal structures were elucidated by X-ray crystallography and their photophysical properties were investigated in detail. All the above complexes exhibit a 1D to 3D supramolecular structure which is linked together by intermolecular weak interaction forces and hydrogen bonds. By regulating ligands and anions, the emission wavelengths of these complexes are quite different in the range from 533 nm to 604 nm. Theoretical calculations and photophysical properties indicate that luminescence is derived from metal-to-ligand charge transfer (MLCT) excited states. In the meantime, the results of calculations show that the stabilization of the increased conjugation of the ligand-based π* orbital is ascribed to the observed bathochromic-shift in the MLCT transitions. [ABSTRACT FROM AUTHOR]

The luminescence properties of the tetranuclear bimetallic lanthanide complexes Sm2Eu2 ( 1) and Eu2Tb2 ( 2), were compared with those of the analogous homometallic complexes [Sm4(μ3-OH)2(salen)2(acac)6(CH3OH)2] ·CH3OH ( 3) and [Eu4(μ3-OH)2(salen)2(acac)6(CH3OH)2] ( 4) [H2salen = N, N′-ethylenebis(salicylideneimine), Hacac = acetylacetonate]. X-ray crystallographic analysis reveals that complexes 3 and 4 have planar tetranuclear structures. For the Eu2Tb2 configurational isomer, the TbIII ion in complex 2 mainly serves as a sensitizer. The quantum yields and lifetime measurements for 2 support the premise that Ln/ Ln energy transfer occurs in such lanthanide bimetallic complexes, along with the usual ligand-to-metal triplet energy pathways. Complexes 3 and 4 exhibit the characteristic metal-centered emission. [ABSTRACT FROM AUTHOR]

The synthesis of four heteroleptic dinuclear Cu(I) complexes bearing tetraphosphine and diimine ligands was reported. Complexes 1–3 were successfully obtained through microwave synthesis while complex 4 was synthesized through traditionally stirring at room temperature. These complexes are listed as follows: [Cu2(Dpq)2(dppeda)](ClO4)2·1.5CH2Cl2 (1), [Cu2(neo)2(dppeda)](ClO4)2·1.3CH2Cl2·1.7C4H10O (2), [Cu2(batho)2(dppeda)](ClO4)2·C4H10O (3), and [Cu2(batho)2(dpppda)](ClO4)2·3CH2Cl2 (4) {(Dpq = pyrazino[2,3-f][1,10]phenanthroline, batho = 4,7-diphenyl-1,10-phenanthroline, neo = 2,9-dimethyl-1,10-phenanthroline, dppeda = N1,N1,N2,N2-tetrakis[(diphenylphosphino)methyl]-1,2-ethanediamine, and dpppda = N1,N1,N4,N4-tetrakis[(diphenylphosphino)methyl]-1,4-benzenediamine}. Their crystal structures have been elucidated by X-ray crystallography and their photophysical properties have been investigated in detail. Photophysical studies and time domain density functional theory (TD-DFT) calculations show that the luminescence performance of these four complexes is ascribed to metal-to-ligand charge transfer (MLCT) mixed with ligand-to-ligand charge transfer (LLCT), and complex 2 shows green emission at 574 nm with the highest quantum yield of up to 52.80%. In addition, the research of photoluminescence properties under the guidance of terahertz spectroscopy technology leads to the preliminary discovery of a correlation between crystal packing and luminescence. It is found that the terahertz spectrum and absorption peak are strongly interdependent on C–H⋯π and π⋯π interactions, and the external weak interactions have negative effects on the luminescence performance. Herein, we predict that the terahertz spectroscopy analysis establishes a bridge between weak interactions (C–H⋯π and π⋯π interactions) and the photoluminescence properties, and puts forward a problem that should be noticed in designing Cu(I) complexes. [ABSTRACT FROM AUTHOR]