Copper Halide Complexes Research Articles

Synthesis, structure and cytotoxicity evaluation of complexes of N1-substituted-isatin-3-thiosemicarbazone with copper(I) halides

Synthesis of Isatin-N1-methyl-thiosemicarbazone (H2itsc-N1-Me, H2L1) and isatin-N1-ethyl-thiosemicarbazone (H2itsc-N1-Et, H2L2) has been carried out and the effect of substituents (at N1 atom of isatin-3-thiosemicarbazones) on nuclearity of copper(I) halide complexes has been investigated. Reactions of copper(I) halides (X=I, Br, Cl) with H2L1 and H2L2 using Ph3P as co-ligand in 1:1:1 (M:L:PPh3) molar ratio in acetonitrile yielded complexes of stoichiometry [CuX(H2L1)(Ph3P)] (X=I, C1; Br, C2; Cl, C3) and [CuX(H2L2)(Ph3P)] (X=I, C4; Br, C5; Cl, C6) respectively. All these complexes have been characterized using analytical and spectroscopic data (IR, 1H NMR and ESI mass). The single crystal structure has been solved for H2L1 and C2. The complex C2 has distorted tetrahedral geometry around copper(I) and isatin-N1-methyl-thiosemicarbazone coordinated to metal center as neutral, bidentate, N3, S-chelating ligand. Elemental analysis suggested the presence of one acetonitrile molecule in complexes C3 and C6 and half CH3CN in complexes C2 and C4 as solvent of crystallization. MTT assay, supported by docking studies have revealed the cytotoxic nature of the compounds C1–C6.

Balanced Dual Emissions from Tridentate Phosphine-Coordinate Copper(I) Complexes toward Highly Efficient Yellow OLEDs.

Dual emissive copper(I) halide complexes TTPPCuX (X = Cl, Br, I) with a triphosphine ligand and stable tetrahedral geometries are constructed, in which TTPPCuI successfully achieves the balanced dual thermally activated delayed fluorescence and phosphorescence (PH) emissions with PH fraction of 39% at ambient temperature, supporting the equal triplet exciton reallocation for the state-of-the-art device performance.

Synthesis and Photoluminescence Properties of CuI Complexes with Chelating Phosphinito Phosphinine Ligands

AbstractInvited for the cover of this issue are the groups of Hansjörg Grützmacher, ETH Zurich, Switzerland, and Zhongshu Li, Sun Yat‐Sen University, Guangzhou, China. The cover image shows the synthesis of dinuclear copper(I) halide complexes from a new diphenylphosphinite phosphinine as chelating ligand and simple CuI halides.

Synthesis and structural characterization of copper(I) halide complexes containing bis(azol-1-yl)methane derived bisphosphines

The copper(I) complexes containing bisphosphines such as bis(2-diphenylphosphinoimidazol-1-yl)methane (1), bis(5-diphenylphosphinopyrazol-1-yl)methane (2) and bis(5-diphenylphosphino-1,2,4-triazol-1-yl)methane (3) have been synthesized. The reaction of 1 with CuX (X=Cl, I) afforded homoleptic dinuclear complexes [Cu2(μ-X)2{CH2(1,3-C3H2N2PPh2)2}2-κ2P,P] (X=Cl, 4; I, 6). However, a mononuclear complex [CuBr(CH3CN){CH2(1,3-C3H2N2PPh2)2}-κ2P,P] (5) was isolated in the reaction of 1 with CuBr. The reaction of 2 with CuX (X=Cl, Br, I) also produced dinuclear complexes [Cu2(μ-X)2{CH2(1,2-C3H2N2PPh2)2}2-κ2P,P] (X=Cl, 7; Br, 8; I, 9). The reaction of 3 with CuCl yielded a novel 1D coordination polymer [Cu2(μ-Cl)2{CH2(1,2,4-C2HN3PPh2)2}-κ2P,N]n (10), whereas homoleptic dinuclear complexes [Cu2(μ-X)2{CH2(1,2,4-C2HN3PPh2)2}2-κ2P,P] (X=Br, 11; I, 12) were obtained in the reactions of 3 with CuX (X=Br, I). Bisphosphines 1 and 2 showed bidentate (κ2P,P) chelating mode of coordination, whereas 3 has adopted bidentate (κ2P,N) chelating mode of coordination in 10. The crystal structures of 4–7 and 10–12 have been established by single crystal X-ray crystallography.

Highly photoluminescent copper carbene complexes based on prompt rather than delayed fluorescence.

Linear two-coordinate copper complexes of cyclic (alkyl)(amino)carbenes (CAAC)CuX (X = halide) show photoluminescence with solid-state quantum yields of up to 96%; in contrast to previously reported Cu photoemitters the emission is independent of temperature over the range T = 4-300 K and occurs very efficiently by prompt rather than delayed fluorescence, with lifetimes in the sub-nanosecond range.

Synthesis, Spectroscopy, and Structures of Mono‐ and Dinuclear Copper(I) Halide Complexes with 1,3‐Imidazolidine‐2‐thiones

AbstractCopper(I) halides with triphenyl phosphine and imidaozlidine‐2‐thiones (L‐NMe, L‐NEt, and L‐NPh) in acetonitrile/methanol (or dichloromethane) yielded copper(I) mixed‐ligand complexes: mononuclear, namely, [CuCl(κ1‐S‐L‐NMe)(PPh3)2] (1), [CuBr(κ1‐S‐L‐NMe)(PPh3)2] (2), [CuBr(κ1‐S‐L‐NEt)(PPh3)2] (5), [CuI(κ1‐S‐L‐NEt)(PPh3)2] (6), [CuCl(κ1‐S‐L‐NPh)(PPh3)2] (7), and [CuBr(κ1‐S‐L‐NPh)(PPh3)2] (8), and dinuclear, [Cu2(κ1‐I)2(μ‐S‐L‐NMe)2(PPh3)2] (3) and [Cu2(μ‐Cl)2(κ1‐S‐L‐NEt)2(PPh3)2] (4). All complexes were characterized with analytical data, IR and NMR spectroscopy, and X‐ray crystallography. Complexes 2–4, 7, and 8 each formed crystals in the triclinic system with P$\bar{1}$ space group, whereas complexes 1, 5, and 6 crystallized in the monoclinic crystal system with space groups P21/c, C2/c, and P21/n, respectively. Complex 2 has shown two independent molecules, [(CuBr(κ1‐S‐L‐NMe)(PPh3)2] and [CuBr(PPh3)2] in the unit cell. For X = Cl, the thio‐ligand bonded to metal as terminal in complex 4, whereas for X = I it is sulfur‐bridged in complex 3.

π-Rich σ(2)P-heterocycles: bent η(1)-P- and μ(2)-P-coordinated 1,3-benzazaphosphole copper(I) halide complexes.

The reaction of 1-neopentyl-1,3-benzazaphosphole 1 with CuCl, CuBr, or Cu(SMe2)Br in THF at room temperature provides sparingly soluble [Cu7(μ(2)-L6)(μ(2)-X7)](+)[CuX2](-) cluster complexes 2a,b (L indicates coordinated 1, a X = Cl, b X = Br), with loosely bound THF, in high yields. The conversions proceed via transient THF-soluble labile [(L2CuX)2] complexes. Separation before complete conversion, combined with suitable conditions for crystallization, allowed these intermediates to be trapped. Depending on the reactant ratios, crystals of the clusters or of dimeric L2CuX complexes were formed. The crystal structure analyses of 2a·4THF and the dimers 3b [{Cu(η(1)-L)2(μ(2)-Br)}2], 4b [{Cu(μ(2)-L)(η(1)-L)(κBr)}2], 5a·2MeOH, and 5b·2MeOH [{Cu(μ(2)-L)(η(1)-L)(κX···HOMe)}2] generally display μ(2)-P- and/or tilted η(1)-P-coordination, contrasting with the preference for the η(1)-P in-plane coordination mode of phosphinine ligands in their copper(I) halide complexes. DFT studies of geometry-optimized monomers LCuBr, L(CuBr)2, L2CuBr, and the dimers 3b and 4b, calculated at the ωB97xD/cc-PVDZ level, suggest that weak competing interactions with the solvent THF and the entropy factor of the dimerization result in lability and a subtle balance between the different complexes in solution, whereas the particular coordination observed in the crystals is attributable to conservation of the delocalized π-system in the ligand. The HOMO of 4b is composed of Cu d orbitals and the π-type HOMO of the bridging ligand. Interestingly, despite the rather short Cu···Cu interatomic separation (2.726 Ǻ), no bond critical point could be located in 4b, indicating the absence of weak cuprophilic interactions in this compound.

Luminescent copper(I) halide and pseudohalide phenanthroline complexes revisited: simple structures, complicated excited state behavior.

We have synthesized a series of luminescent trigonal [CuX(dtbphen)] (X = I (), Br (), Cl (), CN (), dtbphen = 2,9-di-tert-butylphenanthroline) and tetrahedral [Cu2(μ-I)2(L)2] (L = phenanthroline (), 2,9-dimethylphenanthroline ()) copper diimine complexes. Bearing in mind the chemical simplicity of this class of long-known Cu(i) phenanthroline compounds, it is surprising that they exhibit non-trivial photophysical properties, which have not been fully recognized. They display broad XMLCT absorption between ca. 450-600 nm, and the broad emission between ca. 550-850 nm in the solid state occurring with lifetimes on the μs timescale indicates phosphorescence, although the energetic overlap between excitation and emission suggests thermally activated delayed fluorescence (TADF) from S1. In line with the latter assumption, low temperature measurements of in the solid state show an energetic separation of emission and excitation. However, a counter-intuitive decrease of emission intensity and simultaneous increase of the emission lifetime at low temperatures are observed for , which indicates two triplet states also being involved. Our DFT and TD-DFT calculations show that emission from the lowest excited triplet state T1 is of (3)LMXCT nature, separated by only ca. 0.16 eV from S1. Low temperature photophysical measurements at 77 K in a glassy matrix of in 2-Me-THF and of in the solid state are in agreement with the theoretical results, revealing in addition that π-interactions in the solid state also greatly influence the photophysical properties, making a clear conclusion towards TADF ambiguous. This study suggests that other related simple and long-known Cu(i) systems may exhibit a similar, more complex excited state behavior than previously appreciated, involving several emitting states and important intermolecular interactions.

Structural diversity in dinuclear copper(I) halide complexes of 2,4-dithiouracil: Synthesis, crystal structures, induction of DNA damage and oxidative stress mediated by ROS

2,4-Dithiouracil (dtucH2) reacts with [CuX(PPh3)]4 (X=Cl, Br, I) to give dinuclear complexes with different bridging motifs, namely doubly bridged [Cu2(μ-Cl)(μ-S,S-dtucH)(PPh3)4] (1), single bridged [Cu2Br2(μ-S,S-dtucH2)(PPh3)4] (2) and triply bridged [Cu2(μ-I)2(μ-S,S-dtucH2)(PPh3)2] (3). In the structure of 1 the two copper(I) centers are joined by one bridging chlorine atom as well as a 2,4-dithiouracil anion acting as an S,S-donor, while compound 3 contains two bridging iodine atoms besides the neutral bridging 2,4-dithiouracil ligand. The structure of 2 consists of two CuBr(PPh3)2 sub-units joined by the S-atoms of a neutral dtucH2. The biological properties of the new complexes were evaluated in relevance to their binding with calf-thymus double stranded DNA (dsCTDNA) in vitro monitored by mobility shift experiments in agarose gel electrophoresis, and their ability to induce oxidative stress in bacteria Escherichia coli. The experiments showed that these complexes are able to interact with dsCTDNA and to cause DNA damage, and are also able to induce oxidative stress in bacteria. Because of the relevance of these properties, these complexes are regarded as a very promising starting point for biological studies in living systems.

Luminescent dinuclear copper(I) halide complexes double bridged by diphosphine ligands: Synthesis, structure characterization, properties and TD-DFT calculations

Four luminescent copper(I) halide complexes of the type [CuXPh2P(CH2)nPPh2] [X=I, n=4 (1), 5 (2); X=Br, n=4 (3), 5 (4)] were prepared by reacting CuX with the appropriate diphosphine in a 1:1M ratio. All the complexes were characterized by spectroscopic analysis (IR, UV–Vis), elemental analysis and photoluminescence studies. Single-crystal X-ray diffraction revealed that 1 and 2 are both dinuclear structures which are constructed by two μ-I bridges and, especially, two diphosphine ligands as μ2 bridges. The copper(I) iodide complexes are thermally stable, and 2 melts at 242°C. All the complexes exhibit a strong emission in the solid state. The excited states have been assigned as a halide-to-ligand charge transfer (XLCT) state mixed with a small amount of a metal-to-ligand charge transfer (MLCT) transition, based on the TD-DFT calculations. The calculated electronic transitions have also been compared with the experimental absorption spectra to understand the reason why there is some blue-shift of the low-energy band when the halide atom changes from iodine to bromine, and an even greater blue-shift when the ligand changes from DPPP to DPPB.

Synthesis and Characterizations of Strongly Phosphorescent Copper(I) Halide Complexes with Bridged Bis[2-(diphenylphosphino)phenyl]ether Ligand

A series of strongly phosphorescent copper(I) halide complexes, namely [Cu(μ-X)POP]2 (X = Cl (1), Br (2), I (3), Br0.5Cl0.5 (4), POP = bis[2-(diphenylphosphino)phenyl]ether), have been synthesized by reacting CuX with the diphosphine ligand in 1:1 molar ratio. All complexes were characterized by spectroscopic analysis (IR, UV–Vis), elemental analysis, and photoluminescence study. Single-crystal X-ray diffraction revealed that complex 2 is a dinuclear structure which is constructed by two μ-X bridges and two POP ligands as μ2 bridges. Other complexes were determined as isologues of complex 2 by powder X-ray diffraction and elemental analysis. All complexes exhibit intense blue-green phosphorescence with a lifetime of ~1 μs in the solid state. The halogen-mixed complex presents a lightly change in the luminescence comparing to that of parent complexes. The excited states of all complexes have been assigned as halide-to-ligand charge transfer state mixed metal-to-ligand charge transfer character based on the time-dependent density functional theory calculations. All complexes are thermally stable according to thermogravimetric analysis so that they are suitable for applying in luminescent devices.

Synthesis and Characterization of Copper(I) Halide Complexes with N‐(2, 6‐Diisopropylphenyl)‐N′‐benzoylthiourea: Monomeric, Dimeric, and Cage Structures

Abstract The N‐(2, 6‐diisopropylphenyl)‐N′‐benzoylthiourea ligand (shown as L) (1) was synthesized and characterized. Reactions of 1 with CuCl2 and CuBr2 afforded the monomeric L2CuCl (2) and dimeric [LBrCu(μ‐L)]2 (3), respectively, due to the reduction of CuII. The reaction of 1 and CuCl gave the same product L2CuCl (2), while the treatment of 1 with CuBr led to the formation of a rare example of adamantanoid cage (LCu)2(μ‐L)2Cu2(μ‐Br)4 (4) containing enantiomeric couple. The product of 1 and CuI was found to be dimeric [LICu(μ‐L)]2 (5), which is isomorphous to 3. All compounds obtained were fully characterized by elemental analysis, IR, 1H NMR and 13C NMR spectroscopy, and single‐crystal X‐ray diffraction.

Synthesis and characterization of emissive mononuclear Cu(I) complexes with 5-tert-butyl-3-(pyrimidine-2-yl)-1H-1,2,4-triazole

A new series of mononuclear copper(I) halide complexes possessing 5-tert-butyl-3-(pyrimidine-2-yl)-1H-1,2,4-triazole (bpmtzH) and PPh3, Cu(bpmtzH)(PPh3)X (X = I (1); Br (2); Cl (3)), have been synthesized and characterized. As revealed via X-ray crystallography, 1–3 show a chiral, distorted tetrahedral N2PX arrangement, in which bpmtzH is a neutral bidentate chelating ligand using the 4-N of the 1,2,4-triazolyl ring and one N donor from the 2-pyrimidyl ring, consistent with the computational results. A comparatively weak low-energy absorption tail is observed between 320 and 450 nm for CH2Cl2 solutions of 1–3 at room temperature, ascribing to charge-transfer transitions with appreciable metal-to-ligand charge transfer (MLCT) character. Complexes 1–3 in the solid state have good luminescence at ambient temperature, although they are non-emissive in solution. The solid-state emission, most likely originating from both 3MLCT and 3XLCT transitions, can be modulated via alteration of the halide bound to {Cu(bpmtzH)(PPh3)} motif.

Mixed-ligand copper(I) halide complexes bearing 4,5-bis(diphenylphosphano)-9,9-dimethyl-xanthene and N-methylbenzothiazole-2-thione: Synthesis, structures, luminescence and antibacterial activity mediated by DNA and membrane damage

The 1:1M-ratio reaction between copper(I) bromide or iodide and 4,5-bis(diphenylphosphano)-9,9-dimethyl-xanthene (xantphos) in acetonitrile results in the formation of [CuX(xantphos)] (X=Br, I), which further reacts with N-methylbenzothiazole-2-thione (mbtt) to afford the mononuclear mixed-ligand complexes [CuX(xantphos)(mbtt)]. The molecular structures of the complexes, established by single-crystal X-ray diffraction, feature a distorted tetrahedral geometry around the metal center, with the diphosphane acting as a chelate. The new compounds are strongly emissive in the solid state at room temperature. The complexes were also screened for antibacterial activity and their ability to interact with CT-DNA in vitro and to produce reactive oxygen species (ROS).

Synthesis, structure, terahertz spectroscopy and luminescent properties of copper(I) complexes with mercaptan ligands and triphenylphosphine

The reactions of copper(I) halides with triphenylphosphine (PPh3) and mercaptan ligand [2-mercapto-6-nitrobenzothiazole (HMNBT), 2-amino-5-mercapto-1,3,4-thiadiazole (HAMTD) and 2-mercapto-5-methyl-benzimidazole (MMBD)] yielded seven complexes, [CuCl(HMNBT)(PPh3)2] (1), [CuX(HMNBT)(PPh3)]2 (X=Cl, Br) (2–3), [Cu(MNBT)(HMNBT)(PPh3)2] (4), [CuBr(HAMTD)(PPh3)2]·CH3OH (5) and [CuX(MMBD)(PPh3)2]·2CH3OH (X=Br, I) (6–7). These complexes were characterized by elemental analysis, X-ray diffraction, 1H NMR and 31P NMR spectroscopy. In these complexes the mercaptan ligands act as monodentate or bridged ligand with S as the coordination atom. In complexes 1 and 4, hydrogen bonds CH⋯X and weak interactions CH⋯π lead to the formation of chains and 2D network respectively, while complexes 2 and 3 are dinuclear. In 5–7, intramolecular hydrogen bonds link the [CuX(thione)(PPh3)2] molecules and the solvated methanol molecules into centrosymmetric dimers. Complexes 1–5 represent first copper(I) halide complexes of HMNBT and HAMTD. The complexes 1, 5, 6 and 7 exhibit interesting fluorescence in the solid state at room temperature and their terahertz (THz) time-domain spectroscopy was also studied.

Halide impact on emission of mononuclear copper(i) complexes with pyrazolylpyrimidine and triphenylphosphine

A series of mononuclear heteroleptic copper(I) halide complexes, [CuL(PPh3)X] (X = Cl, Br, I), based on 4-(3,5-diphenyl-1H-pyrazol-1-yl)-6-(piperidin-1-yl)pyrimidine (L) and triphenylphosphine, have been synthesized by reaction between CuX (X = Cl, Br, I), L and PPh3 in a molar ratio of 1/1/1 in MeCN solutions. The copper atom, showing the distorted tetrahedral environment, is bound by the N,N-chelating ligand L, triphenylphosphine and a halide ion. The complexes [CuL(PPh3)Cl] and [CuL(PPh3)Br] are isostructural. In CH2Cl2 solutions, L and the complexes [CuL(PPh3)X] (X = Cl, Br, I) display a luminescence band with λ(max) = 377 nm and a lifetime of 1.9 ns (ligand-based luminescence (LL*)). However, the complex [CuL(PPh3)I] has an additional weak luminescence band with λ(max) = 681 nm and a lifetime of 96 ns of (3)MLCT origin. In the solid state, L shows the splitting of the luminescence band to λ(max) = 365 and 384 nm and a slight increase of the lifetime to 2.66 ns. Solid samples of the complexes [CuL(PPh3)X] demonstrate (3)MLCT luminescence bands at 620 nm (X = Cl), 605 nm (X = Br) and 559 nm (X = I) with lifetimes in the range 3.6-11.2 μs, whereas the LL* band (377 nm) is absent. Quantum yields and rate constants of radiative and nonradiative processes were determined in CH2Cl2 solutions and in the solid state for all complexes. The luminescence quantum yield and lifetimes for the solid samples increase in the order [CuL(PPh3)Cl] < [CuL(PPh3)Br] < [CuL(PPh3)I]. This is due to the increase of radiative decay and simultaneous suppression of nonradiative decay. The complex [CuL(PPh3)I] shows a high quantum yield of 29.4% and an excited state lifetime of 11.2 μs.

Crystallographic and magnetic studies of the 2-pyridone/copper halide system

A series of copper halide complexes have been prepared employing 2-pyridone as a ligand. The compounds [CuBr2(2-pyridone)2]2 (1), [CuCl2(2-pyridone)2]2 (2), [CuCl2(2-pyridone)]2 (3), [CuCl2(2-pyridone)3] (4), and [CuCl2·2H2O]2[(2-pyridone)2] (5) were prepared and their structures and magnetic properties studied. Compounds 1 and 2 are dimeric species with the Cu(II) ions bridged by a pair of O-atoms from 2-pyridone molecules. Compound 3 is also a dimer, but in this case bridged by a pair of chloride ions. Only compound 4 is monomeric with fairly well isolated copper(II) ions, while compound 5 is a coordination polymer with the Cu(II) ions linked into chains via pairs of bridging chloride ions. Analysis of the magnetic data reveals that 1 and 2 exhibit significant antiferromagnetic interactions, while 4 is very weakly antiferromagnetic. Compounds 3 and 5 show weak ferromagnetic interactions. Data for 1 and 2 were fit to the antiferromagnetic dimer model with a Curie–Weiss correction to account for interdimer interactions: 1, J=−41.7(1)K, θ=−0.8(1)K; 2, J=−38.2(1)K, θ=−0.7(1)K. Data for 3 were fit to the ferromagnetic dimer model with a Curie–Weiss correction for interdimer interactions:); 2, J=9.4(6), θ=−3.2(3). Interactions in both 4 and 5 were sufficiently weak that data were fit only to the Curie–Weiss expression resulting in θ-values of −0.50(7) and 0.58(4)K respectively.

Copper(I) halide complexes of N-methylbenzothiazole-2-thione: Synthesis, structure, luminescence, antibacterial activity and interaction with DNA

The reactions of copper(I) halides, CuX (X=Cl, Br, I) with N-methylbenzothiazole-2-thione (mbtt), independent of the molar ration chosen (1:2 or 1:3), led to the formation of dinuclear complexes of the formula [CuX(mbtt)2]2, whereas the reactions of CuX and mbtt in the presence of two equivalents of triphenylphosphine (PPh3) afforded mononuclear mixed-ligand complexes of the formula [CuX(PPh3)2(mbtt)]. The molecular structure of a representative compound from each of the two above types of complexes, namely [CuCl(mbtt)2]2 and [CuI(PPh3)2(mbtt)] have been established by single-crystal X-ray diffraction. The new complexes are strongly emissive both in the solid state and in solution. The complexes were also screened for antibacterial activity and their ability to interact with native calf thymus DNA (CT-DNA) in vitro. Both types of complexes showed significant activities against all the bacteria tested as compared to that of standard antibiotic ampicillin, however, the three mixed-ligand complexes including triphenylphosphane as ligand exhibited perceptibly stronger antibacterial activity than the three homoleptic ones possessing only the mbtt ligand. DNA electrophoretic mobility experiments showed that all complexes bind to CT-ds DNA resulting in high molecular weight complexes ending in DNA degradation.

Copper(i) complexes of 1,10-phenanthroline and heterocyclic thioamides: an experimental and theoretical (DFT) investigation of the photophysical characteristics

A series of luminescent mixed ligand complexes of copper(I) halides with 1,10-phenanthroline and the heterocyclic thioamides pyridine-2(1H)-thione (py2SH), pyrimidine-2(1H)-thione (pymtH), 4,6-dimethylpyrimidine-2(1H)-thione (dmpymtH), 1,4,5,6-tetrahydropyrimidine-2-thione (tHpymtH), 1,3-imidazolidine-2-thione (imtH(2)) and 4,5-diphenyl-2-oxazolethiol (dpoxtH) have been synthesized and characterized. The molecular structures of two representative compounds have been established by single-crystal X-ray diffraction. The mononuclear complexes feature the metal in a distorted tetrahedral environment surrounded by the two N atoms of the chelating 1,10-phenanthroline, the thione-S atom of the thioamide, and the halogen atom. The molecular structure, the electronic and photophysical properties and the energetics of the metal-ligand interactions for [CuI(phen)(py2SH)] have been studied by means of density functional calculations.

Synthesis, Structure, and Characterization of Dinuclear Copper(I) Halide Complexes with P^N Ligands Featuring Exciting Photoluminescence Properties

A series of highly luminescent dinuclear copper(I) complexes has been synthesized in good yields using a modular ligand system of easily accessible diphenylphosphinopyridine-type P^N ligands. Characterization of these complexes via X-ray crystallographic studies and elemental analysis revealed a dinuclear complex structure with a butterfly-shaped metal-halide core. The complexes feature emission covering the visible spectrum from blue to red together with high quantum yields up to 96%. Density functional theory calculations show that the HOMO consists mainly of orbitals of both the metal core and the bridging halides, while the LUMO resides dominantly on the heterocyclic part of the P^N ligands. Therefore, modification of the heterocyclic moiety of the bridging ligand allows for systematic tuning of the luminescence wavelength. By increasing the aromatic system of the N-heterocycle or through functionalization of the pyridyl moiety, complexes with emission maxima from 481 to 713 nm are obtained. For a representative compound, it is shown that the ambient-temperature emission can be assigned as a thermally activated delayed fluorescence, featuring an attractively short emission decay time of only 6.5 μs at ϕPL = 0.8. It is proposed to apply these compounds for singlet harvesting in OLEDs.