Heteroleptic phthalocyaninato-[2,3,9,10,16,17,23,24-octakis(octyloxy)phthalocyaninato] rare earth(III) triple-deckers: synthesis and spectroscopic characterization

The homo-dinuclear heteroleptic phthalocyaninato-[2,3,9,10,16,17,23,24-octakis(octyloxy)phthalocyaninato] rare earth(III) triple-decker complexes (Pc)M[Pc(OC₈H₁₇)₈]M[Pc(OC₈H₁₇)₈] (M=Pr, Nd, Sm, Eu, Tb, Dy, Y, Ho, Er, Tm) (1a–10a) and (Pc)M[Pc(OC₈H₁₇)₈]M(Pc) (M=Nd, Sm, Eu, Tb, Dy, Y, Ho, Er, Tm) (2b–10b) were obtained by condensation of bis(phthalocyaninato) rare earths M[Pc(OC₈H₁₇)₈]₂ (M=Pr, Nd, Sm, Eu, Tb, Dy, Y, Ho, Er, Tm), Li₂(Pc) and M(acac)₃·nH₂O (M=Pr, Nd, Sm, Eu, Tb, Dy, Y, Ho, Er, Tm). These novel compounds were characterized by ¹H NMR, mass, electronic absorption (UV–Vis), and IR spectroscopic methods.     

Synthesis and characterization of tetraphenylporphyrin iron(III) complexes with substituted phenylcyanamide ligands

Several five coordinate complexes of [(TPP)Fe^III(L)] in which TPP is the dianion of tetraphenylporphyrin and L is the monoanion of phenylcyanamide (pcyd) (1), 2,5-dichlorophenylcyanamide (2,5-Cl₂pcyd) (2), 2,6-dichlorophenylcyanamide (2,6-Cl₂pcyd) (3), and 2,3,4,6-tetrachlorophenylcyanamide (2,3,4,6-Cl₄pcyd) (4) have been prepared by the reaction of [(TPP)Fe^IIICl] with appropriate thallium salt of phenylcyanamide. Each of the complexes has been characterized by IR, UV-Vis and ¹H NMR spectroscopic data. Dark red-brown needles of [(TPP)Fe^III(2,6-Cl₂pcyd)] (C₅₁H₃₁Cl₂FeN₆ · CHCl₃) crystallize in the triclinic system. The crystal structure of Fe(III) compound shows a slight distortion from square pyramidal coordination with the 2,6-dichlorophenylcyanamide anion in the axial position through nitrile nitrogen atom. Iron atom is 0.47(1) Å out of plane of the porphyrin toward phenylcyanamide ligand. In non-coordinating solvents, such as benzene or chloroform, these complexes exhibit ¹H NMR spectra that are characteristic of high-spin (S = 5/2) species. The X-ray crystal structure parameters are also consistent with high-spin iron(III) complexes. The iron(III) phenylcyanamide complexes are not reactive toward molecular oxygen; however, these complexes react with HCl and produce TPPFe^IIICl.     

Synthesis and characterization of chromium(III) octaphenylporphyrin complexes with various axial ligands: An insight into porphyrin distortion

Influence of axial ligands, MeCN, H₂O, py, and piperidine (pip), on distortion of (2,3,5,10,12,13,15,20-octaphenylporphinato)chromium(III), [Cr(OPP)]⁺, was investigated by X-ray crystallography and UV-vis and ESR spectroscopies. In crystal structures of [Cr(OPP)(MeCN)(H₂O)]ClO₄ · MeCN and [Cr(OPP)(H₂O)₂]ClO₄ · 3THF, the OPP²⁻ ligand had a planar structure. On the other hand, crystal structures of [Cr(OPP)(pip)₂]ClO₄ · 2CH₂Cl₂ and [Cr(OPP)(py)₂]ClO₄ exhibited a waved structure and a saddle-shaped structure with ruffling, respectively. In the UV-vis spectrum of [Cr(OPP)(py)₂]ClO₄ in CH₂Cl₂, the large red shift of the Soret band was observed. Furthermore, the small D value of 0.10 cm⁻¹ was obtained for [Cr(OPP)(py)₂]ClO₄ from the ESR spectrum in frozen 1,2-dichloroethane solution at 5 K. These results suggest that the OPP²⁻ ligand is distorted both in solid and in solution, and that the axial ligand would exert some effects on the porphyrin distortion.     

Synthesis and characterization of gold(III) complexes with alkyldiamine ligands

A series of gold(III) metalacycle of five-, six- and seven-membered ring was prepared by reacting Auric acid (HAuCl₄ · 3H₂O) with 1 equiv. unsubstituted ethylenediamine (en), propylene diamine (pn) and butylenediamine (bn) ligands and with some N-mono-substituted as well as N,N′-disubstituted ethylenediamine ligands. The general formula of these complexes is [Au(alkyldiamine)Cl₂]Cl. These complexes are characterized by melting point and elemental analysis, while structural analysis was done by spectroscopic techniques such as UV-Vis, Far-IR, IR spectroscopy, ¹H and ¹³C solution as well as ¹³C and ¹⁵ N solid-state NMR. The solid-state ¹⁵ N NMR shows that the chemical shift difference between free and bound ligand decreases as bn > pn > en, indicating stronger Au-N bond for bn complex compared to pn and en. UV-Vis shows relative stability of the Au(III) complexes of unsubstituted ethylenediamine with respect to N,N′-di-substituted ethylenediamine. Far-IR data show the six-membered metalacycle gold(III) alkanediamine complexes to be more stable. Spectroscopic data are evaluated by comparisons with calculated data of the built and optimized structure by gaussian03 at the RB3LYP level with LanL2DZ bases set.     

Synthesis and characterization of tetraphenylporphyrin manganese(III) complexes of phenylcyanamide ligands

Several complexes of TPPMn-L, where TPP is the dianion of tetraphenylporphyrin and L is monoanion of 4-methylphenylcyanamide (4-Mepcyd) (1), 2,4-dimethylphenylcyanamide (2,4-Me₂pcyd) (2), 3,5-dimethylphenylcyanamide (3,5-Me₂pcyd) (3), 4-methoxyphenylcyanamide (4-MeOpcyd) (4), phenylcyanamide (pcyd) (5), 2-chlorophenylcyanamide (2-Clpcyd) (6), 2,5-dichlorophenylcyanamide (2,5-Cl₂pcyd) (7), 2,6-dichlorophenylcyanamide (2,6-Cl₂pcyd) (8), 4-bromophenylcyanamide (4-Brpcyd) (9), and 2,3,4,5-tetrachlorophenylcyanamide (2,3,4,5-Cl₄pcyd) (10), have been prepared from the reaction of TPPMnCl and thallium salt of related phenylcyanamide. Each of the complexes has been characterized by IR, UV-Vis and ¹H NMR spectroscopies.4-Methylphenylcyanamidotetraphenylporphyrin manganese(III) crystallized with one molecule of solvent CHCl₃ in the triclinic crystal system and space group with the following unit cell parameters of: a = 11.596(6) Å; b = 11.768(9) Å; c = 17.81(2) Å; and α, β, γ are 88.91(9)°, 88.16(7)°, 67.90(5)°, respectively; V = 2251(3) Å³; Z = 2. A total of 4234 reflections with I > 2σ(I) were used to refine the structure to R = 0.0680 and R_w = 0.2297. The Mn(III) shows slightly distorted square pyramidal coordination with the 4-methylphenylcyanamide in the axial position, coordinated from nitrile nitrogen. The reduction of each of the TPPMn-L complexes was also examined in dichloromethane and spectroelectrochemical behavior of (1) was investigated and compared to TPPMnCl.     

Synthesis of new sandwich intermediate sitting-atop complexes between meso-tetraarylporphyrins and germanium(IV) chloride

GeCl₄ and meso-tetraarylporphyrins (H₂TAPP) react in chloroform solvent for formation sandwich intermediate sitting-atop (i-SAT) complexes, [GeCl₄(H₂TAP)₂]. The various spectral data (¹H NMR, ¹³C NMR, UV-Vis, FT-IR and elemental analysis) were used for characterization of the i-SAT complexes. In the sandwich complexes, the pyrrole rings of two porphyrin macrocycles are tilted up and down and act as electron donors by lone pairs of pyrrolic nitrogens to germanium center of GeCl₄. The spectral results of ¹H NMR and FT-IR showed that in the i-SAT complexes, the hydrogen atoms of two pyrrolic nitrogens remained still on the porphyrin macrocycles.     

Synthesis and structural analysis of calix[4]arene-supported iron(III) complexes

The paper describes the reactivity of calix[4]arene dialkyl- or -silylethers H₂R₂calix, R=Me (1), Bz (2), or SiMe₃ (3) (p-tert.butyl-calix[4]arene=H₄calix), towards the iron(III) complex [FeCl(NSiMe₃)₂(thf)] 4. Bis(silylation) of H₄calix was achieved using a mixture of NEt₃ and Me₃SiCl as silylating agent, which is probably the most convenient and cheapest way for the preparation of H₂(Me₃Si)₂calix 3. [FeCl(N{SiMe₃}₂)₂(thf)] 4 has been obtained from the reaction of [FeCl₃] and commercially available K[N(SiMe₃)₂] in THF. The reactions of 4 with H₂Me₂calix and H₂Bz₂calix afford mononuclear iron(III) chloro compounds [FeCl(R₂calix)] 5 (R=Me) and 6 (R=Bz). The usage of calix[4]arene silyl ether 3 leads to a dinuclear complex [Fe₂({Me₃Si}calix)₂] 7, presumably under Me₃SiCl cleavage of a mononuclear calixarene iron(III) chloro complex. The calix[4]arene ether stabilized iron(III) chloro complexes are susceptible to nucleophilic substitution reactions, as exemplified by the reaction of 5 with sodium azide yielding an azido complex [Fe(N₃)(Me₂calix)] 8. The molecular structures of 4, 5, 6, 7, and 8 in the solid state have been determined by X-ray diffraction.     

Crystal structures, antioxidation and DNA binding properties of Eu(III) complexes with Schiff-base ligands derived from 8-hydroxyquinoline-2-carboxyaldehyde and three aroylhydrazines

Eu(III) and every newly synthesized ligand can form a binuclear Eu(III) complex with a 1:1 metal to ligand stoichiometry and nine-coordinate at Eu(III) center. Every ligand acts as a dibasic tetradentate ligand, binding to Eu(III) through the phenolate oxygen atom, nitrogen atom of quinolinato unit, the CN group (methylene) and ⁻O-CN- group (enolized and deprotonated from OC-NH- group) of the aroylhydrazine side chain. One DMF (N,N-dimethylformamide) molecule is binding orthogonally to the ligand-plane from one side to the metal ion, while another DMF and a nitrate anion (bidentate) are binding from the other. Dimerization of the monomeric unit occurs through the phenolate oxygen atoms leading to a central planar four-membered (EuO)₂ ring. On the other hand, all the ligands and Eu(III) complexes may be used as potential anticancer drugs, binding to Calf thymus DNA through intercalations at the order of magnitude 10⁵-10⁷ M⁻¹. All the ligands and Eu(III) complexes are strong scavengers of hydroxyl radicals and superoxide radicals, but Eu(III) complex containing active phenolic hydroxyl group shows stronger scavenging effects for hydroxyl radicals than others, and Eu(III) complex containing N-heteroaromatic substituent shows stronger scavenging effects for superoxide radicals than others.     

Synthesis,characterization and bioactivity of four novel trinuclear copper(II) and nickel(II) complexes with pentadentate ligands derived from N-acylsalicylhydrazide

Four novel trinuclear copper(II)/nickel(II) complexes with four trianionic pentadentate ligands, N-(3-t-butylbenzoyl)-5-nitrosalicylhydrazide (H₃3-t-bbznshz), N-(3,5-dimethylbenzoyl)salicylhydrazide (H₃3,5-dmbzshz), N-(phenylacetyl)-5-bromosalicylhydrazide (H₃pabshz) and N-(3-t-butylbenzoyl)salicylhydrazide (H₃3-t-bbzshz) have been synthesized and characterized by X-ray crystallography. These trinuclear compounds all have an M–N–N–M–N–N–M core formed by three metal ions and two ligands. The geometries of three Cu(II) ions in compound Cu₃(3-t-bbznshz)₂(H₂O)(DMF)(py)₂ · DMF (1) alternate between distorted square pyramidal and square planar, while in compound Cu₃(3,5-dmbzshz)₂(py)₂ (2), they are all square planar. Three Ni(II) ions in compound Ni₃(pabshz)₂(DMF)₂(py)₂ (3) and Ni₃(3-t-bbzshz)₂(py)₄ · 2H₂O (4) follow square-planar/octahedral/square-planar coordination geometry. Compounds 1, 2 and 4 are bent trinuclear, with the bend angles of 156.4°, 141.49° and 127.1°, respectively, while the three nickel ions in compound 3 are strictly linear, with an angle of 180°. Studies on the trinuclear Ni(II) complexes show that the β-branched N-acylsalicylhydrazide ligands with sterically flexible Cα methylene groups are easier to yield linear trinuclear Ni(II) complexes, while α-branched N-acylsalicylhydrazides ligands tend to form bent trinuclear Ni(II) complexes. Antibacterial screening data indicate that the trinuclear Cu(II) compound 2 is more active than 1 and mononuclear Cu(II) compound, bent trinuclear Ni(II) compound 4 is more active than linear compound 3 and less active than tetranuclear nickel compound in the previous study.     

Synthesis, photophysical and photochemical properties of novel soluble tetra[4-(thiophen-3yl)-phenoxy]phthalocyaninato zinc(II) and Ti(IV)O complexes

The synthesis, photophysical and photochemical properties of zinc and oxo-titanium phthalocyanine derivatives 4-(tetra[4-(thiophen-3yl)-phenoxy]phthalocyaninato)zinc(II), (2); and 4-(tetra[4-(thiophen-3yl)-phenoxy]phthalocyaninato)oxo-titanium(IV), (3), are described for the first time. These peripherally substituted complexes (2 and 3) have been synthesized and characterized by elemental analysis, IR, ¹H NMR and electronic spectroscopy. The compounds (2 and 3) have good solubility in organic solvents such as CHCl₃, DCM, DMSO, DMF, THF and toluene and are not aggregated within a wide concentration range. General trends are described for singlet oxygen, photodegradation, fluorescence quantum yields, triplet quantum yields and triplet life times of these complexes in DMSO, DMF and THF. Compound 2 has higher fluorescence quantum yields, triplet quantum yields and triplet life times than 3, however, the former has lower singlet oxygen quantum yields and photodegradation quantum yields than the latter.     

Synthesis and characterization of novel symmetrical phthalocyanines substituted with four benzo [d] [1, 3] dioxol-5-ylmethoxy groups

Metal (Zn, Cu, Co, Mg) phthalocyanines substituted with four benzo [d] [1, 3] dioxol-5-ylmethoxy unit through oxy-bridges have been synthesized from phthalonitrile derivative, 4-(benzo [d] [1, 3] dioxol-5-ylmethoxy) phthalonitrile. Benzo [d] [1, 3] dioxol-5-ylmethoxy substituted Pcs showed the enhanced solubility in organic solvents. The newly prepared compounds have been characterized by elemental analyses, IR, UV-Vis, ¹H NMR spectra.     

Synthesis, characterization, and redox behavior of six-coordinate (por)Ru(NO)Cl compounds (por = porphyrinato dianion)

A new high-yield preparative route to (por)Ru(NO)Cl compounds (por = porphyrinato dianion) from reactions of (por)Ru(NO)(alkoxide) precursors with boron trichloride is reported. These ruthenium nitrosyl chloride complexes are known to be useful precursors to (por)Ru(NO)-containing derivatives. The crystal structure of (OEP)Ru(NO)Cl (OEP = octaethylporphyrinato dianion) shows that the RuNO linkage is linear. The redox behavior of the (por)Ru(NO)Cl compounds has been determined by cyclic voltammetry. Analysis of the data reveals that the first oxidation of the (por)Ru(NO)Cl compounds is porphyrin-ring centered.     

Synthesis and characterization of monomer and dimer complexes of porphyrin iron(III) with bridging phenylcyanamide ligands

Several new mono and dinuclear complexes of [(P)Fe^III(L)], in which P is the dianion of tetraphenylporphyrin(TPP) and tetramesitylporphyrin(TMP) and L is the monoanion of 4-azo(phenylcyanamido)benzene (apc) (1) and (2) or dianion 1,4-di cyanamidobenzene (dicyd) (3), (4), (7), (8) and 4,4′-azo-diphenylcyanamide (adpc) (5), (6), (9), (10) have been prepared by the reaction of [(P)Fe^IIICl] with appropriate thallium salts of phenylcyanamide derivatives. Each of the complexes has been characterized by FT-IR, UV-Vis, ¹H NMR, MALDI-TOF and EPR spectroscopic data. In non-coordinating solvents (such as toluene or chloroform) these complexes exhibit ¹H NMR spectra that are characteristic of high-spin (S = 5/2) species. The cyanamide group (NCN) of the bridging ligand is coordinated to Fe(III) ions through the nitrile-nitrogen. The iron(III) phenylcyanamide complexes are not reactive toward dioxygen, they convert into [TPPFe^IIICl] when treated with HCl. EPR and NMR have shown that in dinuclear complexes weak magnetic interactions take place between two iron(III) paramagnetic centers.     

Synthesis, characterization and DNA-binding properties of four Zn(II) complexes with bis(pyrrol-2-yl-methyleneamine) ligands

A novel series of bis(pyrrol-2-yl-methyleneamine) ligands H2L(n) (n = 1-4) were synthesized via condensation of diamines with two equivalents of 2-formyl-pyrrole (2). Their Zn(II) complexes were characterized by elemental analyses, mass spectra and IR spectra. The crystal structures of [ZnL(1)]2 and [ZnL(4)]2 obtained from ethanol solution was determined by X-ray diffraction analysis, each of them possesses a double-stranded helical geometry. In addition, the DNA-binding properties of the compounds have been fully investigated by absorption, fluorescence and viscosity measurements.     

Synthesis, characterization and photophysical properties of mixed ligand tris(polypyridyl)chromium(III) complexes, [Cr(phen)2L]

A series of new heteroleptic, tris(polypyridyl)chromium(III) complexes, [Cr(phen)₂L]³⁺ (L = substituted phenanthrolines or bipyridines), has been prepared and characterized, and their photophyical properties in a number of solvents have been investigated. X-ray crystallography measurements confirmed that the cationic (3+) units contain only one ligand L plus two phenanthroline ligands. Electrochemical and photophysical data showed that both ground state potentials and lifetime decays are sensitive to ligand structure and the nature of the solvent with the exception of compounds containing L = 5-amino-1,10-phenanthroline (aphen) and 2,2′-bipyrimidine (bpm). Addition of electron-donating groups in the ligand structure shifts redox potentials to more negative values than those observed for the parent compound, [Cr(phen)₃]³⁺. Emission decays show a complex dependence with the solvent. The longest lifetime was observed for [Cr(phen)₂(dip)]³⁺ (dip = 4,7-diphenylphenanthroline) in air-free aqueous solutions, τ = 273 μs. Solvent effects are explained in terms of the affinity of hydrophobic complexes for non-polar solvent molecules and the solvent microstructure surrounding chromium units.     

Preparation and crystal structure of trans-dihydroxo-[tetrakis(2,6-dichlorophenyl)porphinato]ruthenium(IV)·2toluene

Trans-dihydroxo-[tetrakis(2,6-dichlorophenyl)porphinato]ruthenium(IV) ([Ru(OH)₂(TDCPP)]) was prepared by meta-chloroperbenzoic acid oxidation of [Ru(CO)(TDCPP)] in dichloromethane-toluene, and its crystal structure is reported. Crystal data for [Ru(OH)₂(TDCPP)]·2toluene:C₄₄H₂₂N₄O₂Cl₈Ru·2C₇H₈, orthorhombic, space group Pbca a = 13.149(1), B = 19.893(2), C = 21.093(2)Å, U = 55.17.3(2) ų, Z = 4. The short axial Ru---O bond distance, 1.790(7) Å, is in the range expected for a double Ru(IV)-oxygen bond. Both hydroxo ligands are approximately located in the mean plane of two opposite dichlorophenyl groups. Full-matrix least-squares refinement of positional and thermal parameters, using 2368 unique reflections with F > 2.5 σ (F) led to R(F) = 0.063; R_w = 0.066.     

Synthesis and characterization of the chromium(III) complexes of ethylene cross-bridged cyclam and cyclen ligands

Dichloro(4,10-dimethyl-1,4,7,10-tetraazabicyclo[5.5.2]tetradecane)chromium(III) chloride, Dichloro(4,10-dibenzyl-1,4,7,10-tetraazabicyclo[5.5.2]tetradecane) chromium(III) chloride, and Dichloro(4,11-dimethyl-1,4,8,11-tetraazabicyclo[6.6.2] hexadecane)chromium)(III) chloride have been prepared by the reaction of anhydrous chromium(III) chloride with the appropriate cross-bridged tetraazamacrocycle. Aquation of these complexes proved difficult, but Chlorohydroxo(4,11-dimethyl-1,4,8,11-tetraazabicyclo[6.6.2]hexadecane)chromium)(III) chloride was synthesized directly from chromium(II) chloride complexation followed by exposure or the reaction to air in the presence of water. The four complexes were characterized by X-ray crystal structure determination. All contain the chromium(III) ion in a distorted octahedral geometry and the macrocycle in the cis-V configuration, as dictated by the ethylene cross-bridge. Further characterization of the hydroxo complex reveals a magnetic moment of μ_eff = 3.95 B.M. and electronic absorbtions in acetonitrile at λ_max = 583 nm (ε = 65.8 L/cm mol), 431 nm (ε = 34.8 L/cm mol) and 369 nm (ε = 17 L/cm mol).     

Heteroleptic phthalocyaninato-[tetra(15-crown-5)phthalocyaninato] lanthanides(III) double-deckers: Synthesis and cation-induced supramolecular dimerisation

A series of heteroleptic bisphthalocyaninates [(15C5)₄Pc]M(Pc) ((15C5)₄Pc = 2,3,9,10,16,17,24,25-tetrakis(15-crown-5)phthalocyaninate; Pc = unsubstituted phthalocyaninate; M = La, Sm, Dy, Tm) was synthesized. The raise-by-one-story method was applied in the cases of Sm, Dy and Tm complexes, whereas for the La complex we have developed a new synthetic approach. The complex [(15C5)₄Pc]La(Pc) is the first representative of heteroleptic lanthanum diphthalocyaninates. Homoleptic counterparts M[(15C5)₄Pc]₂ and M(Pc)₂, M = La, Sm, Dy, Tm have also been prepared for comparative studies. The UV-Vis spectral properties of all synthesized heteroleptic compounds were investigated and compared to those of the homoleptic unsubstituted and crown-substituted diphthalocyaninates. Cation-induced dimerisation of heteroleptic complexes was studied. The observed spectral effects were explained in terms of excitonic coupling between chromophoric molecules. The unsymmetrical distribution of electronic density over macrocyclic ligands is established.     

Synthesis, crystal structure and photophysical properties of europium(III) and terbium(III) complexes with pyridine-2,6-dicarboxamide

The reactions of pyridine-2,6-dicarboxamide with europium(III) and terbium(III) triflates led to the formation of mononuclear complexes of formula [Ln(pcam)₃](CF₃SO₃)₃ (Ln = Eu 1, Tb 2; pcam stands for pyridine-2,6-dicarboxamide). From single-crystal X-ray diffraction analysis, the complexes were found to be isomorphous and isostructural. The [Ln(pcam)₃]³⁺ cations and triflate counterions are connected by intermolecular hydrogen bonds, resulting in a 3D network structure. Both the europium(III) and terbium(III) complexes exhibit efficient ligand sensitized luminescence in the visible region with lifetimes of 1.9 ms and 2.2 ms, respectively, in the solid state.     

Synthesis, structural and spectroscopic characterization of mono- and binuclear copper(I) complexes with substituted diimine and phosphine ligands

The reaction of [Cu(CH₃CN)₄]BF₄, 6-(4-methoxyl)phenyl-2,2′-bipyridine (designated as MeO-CNN), and/or tricyclohexylphosphine (PCy₃) and diimine ligands derived from 4,4′-bipyridine gave four mono- and binuclear copper(I) complexes, [Cu(MeO-CNN)₂]BF₄ (1), [Cu₂(MeO-CNN)₂(PCy₃)₂(4,4′-bipy)](BF₄)₂ · 1.5CH₂Cl₂ (2) (bipy = bipyridine), [Cu₂(MeO-CNN)₂(PCy₃)₂(bpete)](BF₄)₂ · 4CH₂Cl₂ (3) (bpete = trans-1,2-bis(4-pyridyl)ethene) and [Cu₂(MeO-CNN)₂(PCy₃)₂(4,4′-azpy)] (BF₄)₂ · 1.5CH₂Cl₂ (4) (azpy = azobispyridine). Crystallographic studies of complexes 1-4 show that each copper(I) center adopts a pseudo-tetrahedral coordination geometry. Complexes 2-4 consists of -Cu(MeO-CNN)(PCy₃) units which are linked through 4,4′-bipy, bpete and 4,4′-azpy, respectively. The UV-Vis spectra of these four complexes all exhibit intense high-energy absorptions at λ_max < 340 nm and broad visible bands in a range of 430-550 nm, ascribed to intraligand (IL π → π^∗) transitions and metal-to-ligand charge-transfer (MLCT) transitions, respectively. The density functional theory calculation was used to interpret the absorption spectrum of 1, which further supports the assignment of MLCT character. The binuclear complexes 2 and 3 both display red solid-state emissions centred at 620 and 660 nm from metal-to-ligand charge-transfer excited state, respectively. Interestingly, the electron paramagnetic resonance (EPR) spectral measurements confirm copper(I) complexes oxidized to corresponding copper(II)-halide product upon excitation at 355 nm in dichloromethane solution.