•Synthesized some agostic dinuclear and trinuclear Cu(I) complexes.•Both trigonal planar and tetrahedral coordination modes were observed for Cu(I) centers.•Studied the complex 31P NMR spectra of the six complexes.Reaction of [Cu(MeCN)4]ClO4 with 1H-imidazo[4,5-f][1,10]phenanthroline derivatives (L1, L2 and L3) and the bulky, rigid chelating diphosphine ligand 9,9-dimethyl-4,5-bis(diphenylphosphino)-9H-xanthene (xantphos) under alkaline conditions in different ratios afforded a series of luminescent binuclear [Cu2(L–H)(xantphos)2]ClO4 (L = L1, 1a; L2, 2a; L3, 3a) and trinuclear [Cu3(L–2H)(xantphos)3]ClO4 (L = L1, 1b; L2, 2b; L3, 3b) complexes. Both trigonal planar and tetrahedral coordination modes of Cu(I) centers were observed for complexes 1a and 1b, and they exhibit obvious CH⋯Cu agostic or anagostic interaction for the trigonal planar Cu(I) centers. The 31P NMR, electronic absorption and emission spectra are discussed. All the complexes exhibit weak luminescence at room temperature in the solid state and in the solution.A series of red luminescent dinuclear and trinuclear copper(I) complexes using 1H-imidazo[4,5-f][1,10]phenanthroline derivatives and 9,9-dimethyl-4,5-bis(diphenylphosphino)-9H-xanthene as mixed ligands have been synthesized and characterized. Both trigonal planar and tetrahedral coordination modes of Cu(I) centers along with CH⋯Cu agostic or anagostic interaction were observed in the crystal structures of complexes 1a and 1b.

Four half-sandwich type mononuclear lanthanide crown ether complexes with the formula [Ln(12-crown-4)(NO3)3] (Ln3+ = Dy3+ (1), Tb3+ (2), Ho3+ (3), and Er3+ (4); 12-crown-4 = 1,4,7,10-tetraoxacyclododecane) were successfully synthesized and structurally characterized. Ac magnetic susceptibility measurements reveal that dysprosium complex 1 behaves as a typical single-ion magnet, while solid state photoluminescence studies show that complexes 1 and 2 have the respective lanthanide(III) luminescence characteristics.

•Synthesized five Cu(I) complexes with good luminescence behavior.•Analyzed why such complexes are stable to air and moisture from crystallography.•Studied the luminescence lifetimes, quantum yields and aggregation-induced emission.Reaction of 4-bromo-2-(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)phenol (BIPP), chelating diphosphine ligands and [Cu(MeCN)4]ClO4 afforded five mononuclear [Cu(BIPP)(PP)]ClO4 (PP = dppe, 1; dppp, 2; bdpp, 3; POP, 4; xantphos, 5) complexes with good phosphorescent emission in the solid state. All the complexes are characterized by elemental analyses, electrospray Ionization mass spectra, 1H and 31P NMR spectra and X-ray single crystallography. The photoluminescence quantum yields of complexes 1–5 are from less than 0.010 to 0.262 in the solid state under air atmosphere, which increase with the increasing rigidity of diphosphine ligands and the increasing strength of intermolecular and intramolecular π⋯π interactions. The aggregation-induced emission of complexes 4 and 5 at room temperature was investigated.Five mononuclear [Cu(BIPP)(PP)]ClO4 (PP = dppe, 1; dppp, 2; bdpp, 3; POP, 4; xantphos, 5) complexes with good phosphorescent emission were synthesized. Their photoluminescence quantum yields in the solid state increase with the increasing rigidity of diphosphine ligands and the increasing strength of intermolecular and intramolecular π⋯π interactions. The aggregation-induced emission of complexes 4 and 5 was investigated.

Reaction of 5,6-diamino-1,10-phenanthroline (dap), chelating diphosphine ligands, 9,9-dimethyl-4,5-bis(diphenylphosphino)-9H-xanthene (xantphos) and bis[(2-diphenylphosphino)phenyl] ether (POP) with [Cu(MeCN)4]ClO4 afforded mononuclear [Cu(dap)(PP)]ClO4 (PP = xantphos, 1a; POP, 2a), binuclear [Cu2(μ-pdi)(PP)2](ClO4)2 (pdi = 1,10-phenanthroline-5,6-diimine) (PP = xantphos, 1b; POP, 2b) and [Cu2(μ-ttpd)(xantphos)2](ClO4)2 (1c) (ttpd = 8b,9,18,18a-tetrahydrotetrapyrido[3,2-a:2′,3′-c:3″,2″-h:2‴,3‴-j]phenazine-8b,18a-diamine) complexes. The ligand pdi with a quinone diimine form in complexes 1b and 2b is suggested to result from an in-situ two-electron oxidation of dap under the catalysis of Cu(I) and is stabilized by the coordination to Cu(I) ion, while the unprecedented ligand ttpd in complex 1c is suggested to originate from the in-situ oxidation, addition and cyclization reaction of dap induced and stabilized by crystallized Cu(I)-diimine–diphosphine complex. The plausible formation mechanisms for the Cu(I) complexes are proposed.Reaction of 5,6-diamino-1,10-phenanthroline (dap), two chelating diphosphine ligands (PP) with [Cu(MeCN)4]ClO4 afforded three types of Cu(I)-diimine–diphosphine complexes, [Cu(dap)(PP)]ClO4, [Cu2(μ-pdi)(PP)2](ClO4)2 and [Cu2(μ-ttpd)(xantphos)2](ClO4)2, where dap was suggested to undergo in-situ oxidation, addition and cyclization reaction induced by Cu(I) complexes.

Phosphorescent binuclear copper(I) complexes [Cu2(BrphenBr)2(Ph2P(CH2)nPPh2)2](ClO4)2 with different conformations are obtained by reaction of [Cu(NCCH3)4]ClO4, 3,8-dibromo-1,10-phenanthroline (BrphenBr), and corresponding diphosphine ligands, where n = 1, 4, 5, and 6 in complexes Cu-1, Cu-2, Cu-3, and Cu-4, respectively. Complex Cu-4 exhibits both the eclipsed and the staggered conformations of 18-membered Cu2C12P4 metallacycles in a 1:1 ratio in the crystal structure. All complexes are very stable to air and moisture in the solid state because of the high level of protection of all the Cu(I) centers, N and P atom centers resulting from the close contact of BrphenBr and diphosphine ligands, and what is more important is that there exist very soft P donors and the chelating effect of aromatic N atoms. The ESI-MS result through changing the collision cell energy from 0 to 20 eV suggests that the corresponding [Cu2(Ph2P(CH2)nPPh2)2]2+ cations are the thermodynamically stable species, while [Cu2(BrphenBr)2(Ph2P(CH2)nPPh2)2](ClO4)2 are stable products in crystallization kinetics in solutions. All complexes Cu-1–Cu-4 display good aggregation-induced phosphorescence emission (AIPE) behavior in CH2Cl2/hexane mixed solvents, which are suggested to arise from restriction of intramolecular rotation. Aggregation-induced emission (AIE) of complexes Cu-1–Cu-4 in PBS/DMSO (99:1, v:v) is used for living HeLa cell imaging successfully with green intracellular emission image.

•Analysized why such complexes are stable to air and moisture from crystallography.•Studied the binding ability between two ligands and Cu(I) ions through ESI-MS.•Studied the absorption, emission spectra and luminescence lifetimes systematically.Reaction of [Cu(NCCH3)4]ClO4 with 5,5′-dibromo-2,2′-bipyridine (BrbpyBr) and diphosphine ligands Ph2P(CH2)xPPh2 (x = 1, 4, 5, 6) in dichloromethane gives good yields of a series of binuclear copper(I) complexes [Cu2(BrbpyBr)2(Ph2P(CH2)xPPh2)2](ClO4)2, where x is 1, 4, 5 and 6 in complexes 1–4, respectively. The crystallographic data and the space-filling drawings of complexes 1 and 3 show that the Cu(I) centers, N atom centers and P atoms centers are well protected by the close contact of BrbpyBr and diphosphine ligands, which may be the reasons why complexes 1–4 are so stable to air and moisture in the solid state. The ESI-MS result through changing the collision cell energy from 0 to 15 eV suggests that the binding energies between Cu(I) ions and Ph2P(CH2)xPPh2 ligands are much larger than that between Cu(I) and BrbpyBr ligand in the [Cu2(BrbpyBr)2(Ph2P(CH2)xPPh2)2]2+ cations, confirming that the corresponding [Cu2(Ph2P(CH2)xPPh2)2]2+ cations are the thermodynamically stable products in DCM solutions. All the complexes 1–4 display good phosphorescent emission in the solid state.Binuclear complexes [Cu2(BrbpyBr)2(Ph2P(CH2)xPPh2)2](ClO4)2 with all centres of Cu(I) ions, N and P atoms well protected by two kinds of ligands display good stability to air and mositure and exhibit phosphorescent emission in the solid state. The ionization behavior and the relative binding ability between Cu(I) ions and two kinds of ligands were studied through ESI-MS.

•Synthesized three organogold(I)-diphosphine-acetylides complexes.•The crystal structure, absorption and emission spectra were discussed.•All the complexes display good luminescence.Depolymerization of (C14H9CCAu)n (C14H9CCH = 9-ethynyl-anthracence) with diphosphine ligands Ph2P(CH2)xPPh2 (x = 4 dppb, 5 dpppen, 6 dpph) in CH2Cl2 afforded the corresponding binuclear gold(I)-diphosphine-acetylides[(C14H9CCAu)2(μ-dppb)](1), [(C14H9CCAu)2(μ-dpppen)] (2) and [(C14H9CCAu)2(μ-dpph)] (3). The crystal structures of complexes 1⋅tht (tht = tetrahydrothiophene) and 3 are determined and analyzed. All the complexes 1–3 display good photoluminescence both in the solid state and in dichloromethane solutions.

Four half-sandwich type mononuclear lanthanide crown ether complexes with the formula [Ln(12-crown-4)(NO3)3] (Ln3+ = Dy3+ (1), Tb3+ (2), Ho3+ (3), and Er3+ (4); 12-crown-4 = 1,4,7,10-tetraoxacyclododecane) were successfully synthesized and structurally characterized. Ac magnetic susceptibility measurements reveal that dysprosium complex 1 behaves as a typical single-ion magnet, while solid state photoluminescence studies show that complexes 1 and 2 have the respective lanthanide(III) luminescence characteristics.