Syntheses and Crystal Structures of 3-Carboxylsalicylidenefurfurylimine And Its Trinuclear Nickle(Ⅱ) Complex

A Schiff base ligand(H2CSF,C13H11NO4,1) derived from 3-carboxylsalicylaldehyde and furfurylamine,and its trinuclear complex [Ni3(CSF)2(CH3COO)2(DMF)2(H2O)2](2) were synthesized.Compound 1 was characterized by elemental analysis,1H NMR,IR,MS and X-ray diffraction analysis.The crystal of 1 belongs to the monoclinic system,space group P21/c with a = 8.472(2),b = 19.743(5),c = 7.2300(18) ,β = 110.278(4)°,V = 1134.4(5) 3,Z = 4,Mr = 245.23,Dc = 1.436 g·cm-3,μ = 0.108 mm-1,F(000) = 512,λ = 0.71073 ,the final R = 0.0440 and wR = 0.1199 for 1426 observed reflections(I 2σ(I)).In the crystal of 1,there exist intramolecular hydrogen bonds and weak intermolecular C-H···O hydrogen bonds.Compound 2 was characterized by elemental analysis,IR,TG and X-ray diffraction analysis.The crystal of 2 is of triclinic system,space group P1 with a = 10.1237(17),b = 10.4086(18),c = 10.4884(18) ,α = 82.528(2),β = 67.339(2),γ = 83.010(2)°,V = 1008.1(3) 3,Z = 1,Mr = 962.87,Dc = 1.586 g·cm-3,μ = 1.463 mm-1,F(000) = 498,λ = 0.71073 ,the final R = 0.0517 and wR = 0.0805 for 2065 observed reflections(I 2σ(I)).The geometry of the trinuclear molecule is centrosymmetric,in which every Ni(Ⅱ) ion is coordinated in a slightly distorted octahedron.The three Ni(Ⅱ) ions are arranged in a straight line.The two CSF2-ions act as NOO tridentate ligands with the phenolate and carboxylate oxygen as bridging atoms.The coordination atoms of CSF2-anions and water molecules are coordinated on the equatorial plane,while the two bridging acetate ions and two DMF are trans-coordinated on the apical sites.     

Synthesis, Crystal Structure and Properties of a Novel Tetranuclear Nickel（II） Complex with Azo-enolic-2-hydroxybenzamide

A novel tetranuclear nickel(Ⅱ) complex [Ni4L2(DMF)2(H2O)2·2DMF] (1,H4L=azo-enolic-2-hydroxybenzamide, DMF=N,N-dimethyl-formamide) has been synthesized and characterized by elemental analysis, UV, IR and X-ray single-crystal diffraction characterization. Complex 1 crystallizes in the monoclinic system, space group P21/n with a=8.8944(11), b=14.4583(18), c=18.097(2) , β=90.00(2)o, Z=2 , V=2327.2(5)3 , C40H48N12Ni4O14 , Mr=1155.66, Dc=1.649g/cm 3 , μ=1.672 mm-1 , F(000)=1192, R=0.0392 and wR=0.0958. The local coordination environment around the nickel ions exist a distorted octahedral and quadrangle geometry in the molecular structure. Complex 1 exhibits strong photoluminescent emission in the ultraviolet region at room temperature. The electrochemical studies reveal that redox of Ni 3+ /Ni 2+ in the complex is a quasi-reversible process.     

Simple Preparation,Structure and Conductivity of Nickel(Ⅱ) Benzenetricarboxylate Ni_3(BTC)_2·12H_2O

Proton-conductive crystalline metal-organic framework nickel(Ⅱ) benzenetricarboxylate Ni3(BTC)2·12H2O(MOF-Ni) was prepared by the reaction of nickel(Ⅱ) nitrate and 1,3,5-benzenetricarboxylic(BTC) acid in a mixed solvent of N,N-dimethylformamide(DMF)/C2H5OH/ H2O(1:1:1, ν/ν) at low temperature and short reaction time. It was characterized by thermogravimetric analyses(TG), FT-IR and N2 adsorption-desorption. Single-crystal X-ray diffraction analysis indicated that the complex belongs to monoclinic system, space group C2 with a = 17.407(6), b = 12.878(5), c = 6.542(2) , β = 112.07°, V = 1359.0(8)3, Dc = 1.971 g/cm3, μ = 2.166 mm-1 and Z = 2. Linear polarization resistance(LPR) analysis showed that the complex possesses semiconducting properties.     

Crystal Structure,Spectroscopic Characterization,and Electrochemical and Thermal Stability Properties of a Dinuclear Nickel(Ⅱ) Complex

A new nickel(Ⅱ) complex Ni_2(L)_2(2,2?-bipy)2·5.5H_2 O with methy-bicycle[2.2.1]hept-5-ene-2,3-dicarboxylic acid(H2L) and 2,2?-bipyridine(2,2?-bipy) as ligands has been synthesized in the mixed solvent DMF and water(v:v = 5:2). It crystallizes in the triclinic space group P1 with a = 10.414(2), b = 12.884(3), c = 16.176(4) ?, α = 70.715(5), β = 80.599(5), γ = 77.383(6)o, V = 1989.4(8) ?3, Dc = 1.531 g/cm3, Z = 2, F(000) = 958, GOOF = 1.028, the final R = 0.0808 and w R = 0.2036. The crystal structure shows that the whole molecule consists of two independent dinuclear units, in which two nickel ions are bridged by two μ2-η1:η0 3-carboxylate groups of L2- anions. The coordination environment of Ni(Ⅱ) ion is Ni N_2O_3, giving a distorted square pyramidal geometry. The thermal stability and electrochemical properties of the complex were investigated.     

Syntheses,Crystal Structures and Antibacterial Activities of Schiff Base Ligand and Its Nickel(Ⅱ) Complex

A complex [NiL2] was synthesized, in which L, or to be exact, a Schiff base ligand(HL), was derived from the condensation of 1-phenyl-3-methyl-4-phenylacetyl-5-pyrazolone(PMPAP) with L-phenylalanine methyl ester. They were characterized by IR and single-crystal X-ray diffraction. Green block crystals of both ligand and its complex were grown at room temperature. The ligand, which consists of two individual fragments, crystalizes in the P1 space group(a = 5.6268(5), b = 10.6892(11) and c = 19.4869(18) ). The complex crystalizes in the P21 space group(a = 21.4076(18), b = 9.4792(8) and c = 25.287(2) ), which consists of a nickel six-coordinated compound. Every fragment is a distorted octahedron with four oxygen and two nitrogen atoms. The Schiff base ligand(HL) and its complex have been tested in vitro to evaluate their antibacterial activity against bacteria Escherichia Coli and Bacillus subtilis. It is found that the complex has higher activity than the corresponding free Schiff base ligand(HL) against the same bacterial.     

Synthesis, Crystal Structure and Luminescence Property of a Cd(Ⅱ) Complex Assembled by 4-Carboxymethoxy Phenylacetic Acid

A new structure with the molecular formula [CdL]n was formed by CdSO4 with 4-carboxymethoxy phenylacetic acid (H2L) through the hydrothermal method. The complex was characterized by elemental analysis and infrared spectroscopy. The structure of the complex was determined by single-crystal X-ray diffraction, which is of monoclinic system, space group P21/c with a = 10.3887(2), b = 7.10710(10), c = 14.7212(2) , β = 120.6940(10)°, V = 934.65(3) 3, Dc = 2.278 g·cm-3, Z = 4, F(000) = 624, S = 1.022, the final R = 0.0187 and wR = 0.0487 for 2000 observer reflections (Ⅰ > 2σ(Ⅰ)). The center metal ion Cd(Ⅱ) in the complex is six-coordinated in a distorted octahedral geometry, and is connected with L ligands to form a 3D fishing net structure, which is a novel (3,6) network topology. The luminescence of the complex has been investigated, and the result reveals that it displays luminescent property in the voilet region.     

Synthesis, Crystal Structure and Luminescence Property of a 2D Mn（II） Coordination Polymer Based on Isoniazid

A novel 2D Mn(Ⅱ) coordination polymer [Mn(CH3COO)2(INH)]n(INH=isoniazid) has been synthesized in DMF solution with isoniazid and Mn(CH3COO)2 . The polymer was characterized by single-crystal X-ray diffraction analysis, FTIR and X-ray powder diffraction (XRPD). The crystal belongs to the monoclinic system, space group P2 1 /c with a=9.3251(18), b=16.340(3), c=8.8096(17) , β=94.747(3)°, V=1337.7(4) 3 , Z=4, μ(MoKα)=1.006 mm -1 , F(000)=636, R=0.0754 and wR=0.1375 (I > 2σ(I)). In the complex, each Mn(Ⅱ) atom is coordinated to three CH3COO- groups and two INH ligands. The Mn(Ⅱ) atoms locate in a distorted coordination octahedron and are bridged by CH3COO- ions to form a 1D S shaped chain extending along the c direction. The INH molecules act as bridges to link the Mn(Ⅱ) atoms of adjacent chains and further construct a lamellar polymer. The remaining coordination site is occupied by an O atom of the other CH3COO-. The experimental results show that the title complex has good luminescence property and could be used as potential optical materials.     

Synthesis, Crystal Structure and Antimicrobial Activity of a Novel Ni(II) Complex

A new nickel(II) complex, C34H38N8NiO4, has been prepared and charac- terized by X-ray diffraction analysis. It crystallizes in the monoclinic system, space group P21/c with a = 11.715(5), b = 12.328(5), c =11.113(5) , β = 92.589(5)°, Z = 2, Dc = 1.411 g/cm3, μ = 0.658 mm-1, the final R = 0.0427 and wR = 0.1099 for 2229 observed reflections with I > 2σ(I). The complex is a centrosymmetric plane in which nickel(II) is coordinated in a regular octahedron to the ligand phenytoin through the nitrogen atoms of ethylenediamine, imine and amine. The complex was valued for its antimicrobial activity against bacterial strands using the agar diffusion method, and found to be active against the four test bacterial organisms. Preliminary screening for antimicrobial activities showed that the title complex is quite active against standard strains of Salmonella species, Staphylococcus aureus, Bacillus pumilus and Eschierichia coli.     

Synthesis, Characterization, Crystal Structure and Antibacterial Activities of a Nickel（Ⅱ） Complex with 2＇-（2-Thienylidene）-hydroxybenzoylhydrazide

In the ethanol solvent, a nickel(Ⅱ) complex Ni(C12H10N2O2S)2 upon reaction of 2'-(2-thienylidene)-hydroxybenzoylhydrazide with nickel acetate was synthesized, and its structure was characterized by IR, UV, elemental analysis and X-ray diffraction analysis. The crystal belongs to monoclinic system, space group C2/c with a = 22.052(3), b = 5.9681(6), c = 18.522(2) (A), β = 110.679(4)° , V = 2280.6(4) (A)3, Z = 4, Mr = 551.27, μ = 1.606 mm-1, Dc = 1.075 g/cm3, F(000) = 1136 and Rint = 0.0556. The nickel(Ⅱ) atom in the compound is four-coordinated with two nitrogen atoms from amide and two oxygen atoms from keto group. The biological activities have been measured, show- ing the compound exhibits better anti-bacterial activity than the ligand.     

Synthesis and Structural Characterization of a Supramolecular Compound [(C_8H_9NO_2)·HgI_2]_n Constructed from Hg…I and C–H…O Linkage

The title complex [(C8H9NO2)·HgI2]n has been synthesized from the reaction of pyridine-3-ethylformate with mercury iodide in the mixture of DMF and absolute methanol. Its structure was determined by IR, elemental analysis and X-ray single-crystal diffraction analysis. The crystal is of monoclinic system, space group P21/n with a = 4.3397(5), b = 25.051(3), c = 12.3719(13) , β = 92.2130(10)o, C8H9HgI2NO2, Mr = 605.55, V = 1344.0(3) 3, Z = 4, Dc = 2.993 mg·m-3, F(000) = 1064, μ = 16.024 mm-1, the final R = 0.0258 and wR = 0.0504. In the title complex, the center Hg(Ⅱ ) exhibits a four-coordinated distorted tetrahedral geometry. A three-dimensional network arrangement is presented via Hg…I weak interactions among adjacent molecules.     

A 3D Nickel(Ⅱ) Complex Constructed by Bis(2-dimethylaminoethyl) Ether: Solvothermal Synthesis,Crystal Structure and Catalytic Properties

Treatment of bis(2-dimethylaminoethyl) ether(BDMAE) with nickel acetate afforded a novel 3D nickel(Ⅱ) complex [Ni(BDMAE)(H_2O)_3·(CH_3COO)_2·(H_2O)_2] under solvothermal conditions. Its crystal structure was characterized by elemental analysis, IR spectrum, PXRD and single-crystal X-ray diffraction analysis. The complex belongs to the orthorhombic system, space group C2221 with a=8.823(2), b=13.932(3), c=17.563(4) ?, V=2158.9(8) ?~3, Z=4, C_(12)H_(36)N_2NiO_(10), Mr=427.14, Dc=1.314 g/cm~3, F(000)=920 and μ=0.944 mm~(-1). Single-crystal X-ray diffraction reveals that the mononuclear nickel(Ⅱ) ion is six-coordinated to one oxygen, two nitrogen atoms of the BDMAE ligand and three oxygen atoms of coordinated water molecules. The complex exhibits a 3D supramolecular structure through a variety of intermolecular and intramolecular hydrogen bonding interactions. In addition, the complex has been investigated for catalytic properties towards the Henry reaction of nitromethane with p-nitrobenzaldehyde, and the results indicated that the 1-p-nitrophenyl-2-nitroethanol product was obtained in excellent yield under optimum conditions with the complex as the catalyst.     

Bis(1-(4-(dimethylamino)benzylidene)-4-phenylthiose micarbaznato)palladium(Ⅱ):Synthesis,Crystal Structure and Its Dual Fluorescence Property

The title compound bis(1-(4-(dimethylamino)benzylidene)-4-phenylthiosemicar-bazato)-palladium(Ⅱ)(PdL2) was obtained by reacting 1-(4-(dimethylamino)benzylidene)-4-phenyl-thiosemicarbazide with dichlorobis(benzonitrile)palladium(Ⅱ) in methanol,and its structure was characterized by single-crystal X-ray diffraction.The crystal of PdL2 was obtained in dimethyl-formamide(DMF) solvent with solvent molecules involved in the cell and crystallizes in the monoclinic system,space group C2 with a = 18.485(15),b = 7.090(5),c = 17.595(11) ,β = 121.21(3)o,V = 1972(2) 3,Z = 2,Mr = 847.40,Dc = 1.427 g/cm3,μ = 0.624 mm-1,F(000) = 880,R = 0.0607 and wR = 0.1358.The Pd atom adopts a distorted square planar coordination geometry with two Pd-N and two Pd-S bonds.The ligand loses a proton from its tautomeric thiol form and coordinates to the Pd atom via mercapto sulfur and the imine nitrogen atom,which binds to palladium as bidentate N,S-donors forming five-membered chelate rings.The complex formed hydrogen bonding interaction with solvent DMF molecules from the hydrogen of phenylamine to the oxygen of DMF and several intramolecular hydrogen bonds.Pd(Ⅱ) perturbed ligand π-π* transition and metal-to-ligand charge transfer(MLCT) transition are observed in its electronic absorption spectra.The complex exhibits intraligand 1π-π*(IL) state and MLCT state dual fluorescent emissions in organic solvent at room temperature.     

Synthesis, Characterization, Crystal Structure and Antibacterial Activities of a Nickel(Ⅱ) Complex with 2'-(2-Thienylidene)-hydroxybenzoylhydrazide

In the ethanol solvent, a nickel(II) complex Ni(C12H10N2O2S)2 upon reaction of 2'-(2-thienylidene)-hydroxybenzoylhydrazide with nickel acetate was synthesized, and its structure was characterized by IR, UV, elemental analysis and X-ray diffraction analysis. The crystal belongs to monoclinic system, space group C2/c with a = 22.052(3), b = 5.9681(6), c = 18.522(2) , β = 110.679(4)°, V = 2280.6(4) 3, Z = 4, Mr = 551.27, μ = 1.606 mm-1, Dc = 1.075 g/cm3, F(000) = 1136 and Rint = 0.0556. The nickel(Ⅱ ) atom in the compound is four-coordinated with two nitrogen atoms from amide and two oxygen atoms from keto group. The biological activities have been measured, show- ing the compound exhibits better anti-bacterial activity than the ligand.     

Solvothermal Synthesis,Crystal Structure and Antimicrobial Activity of a Novel Imide Nickel Complex [Ni（CH_3CONCOCH_3）_2·2（H_2O）]

A novel imide nickel complex [Ni(CH3CONCOCH3)2·2(H2O)] was synthesized by the solvothermal reaction of nickel acetate tetrahydrate and acetonitrile.What amazed us is that acetonitrile had changed into acetyl imide in enol form during the formation process of the title complex.The complex was characterized by elemental analysis,IR spectrum and X-ray single-crystal diffraction analysis.It crystallizes in the orthorhombic system,space group Pbca with a = 7.4503(7),b = 13.1089(12),c = 14.1303(14),V = 1380.0(2)3,Dc = 1.420 g/cm3,Mr = 294.94,Z = 4,F(000) = 616,μ = 1.422 mm-1,the final R = 0.0487 and wR = 0.1482.The four-coordinated nickel(II) center is surrounded by 4O atoms from two imide ligands and has a distorted square planar geometry.The complex is connected to form a supramolecule with an infinite three-dimensional network through intramolecular and intermolecular hydrogen bonds.Antimicrobial activity was investigated by agar diffusion method,and the result showed that the complex was active against coli bacillus,staphylococcus aureus and bacillus subtilis.The thermal stability of the title complex was also studied by TG-DTA method.     

Crystal Structure of Tris(2,2'-bipyridine)nickel (Ⅱ) Tetrachlorozincate

A bimetallic complex Ni[C10H8N2]3[ZnCl4] has been synthesized and its crystal structure determined at room temperature. The complex crystallizes in the trigonal system, space group R3c, with a = 13.343(2), b = 13.343(2), c =58. 932(12) A, V= 9087(3) A 3, Z = 12, NiZnC30N6CI14H24, Mr=734.30, Dc=1.611 g/cm3, μ= 1. 799 mm-1, F(000)=4464. Least-squares refinement of the structure leads to the agreement factors R1=0. 0278 and wR2=0. 0741 for the observable reflections. The complex consists of discrete tris (2, 2'-bipyridine) nickel (Ⅱ)cation, [Ni-(bipy)3]2+, and tetrachlorozincate anion, [ZnCl4]2-. Each nickel (Ⅱ)atom is six coordinated in an octahedron with six nitrogen atoms of three 2,2'-bipyridine ligands. The mean Ni(Ⅱ)-N bond length is 2. 089(2) A. The zinc(Ⅱ) atom is coordinated with four chloride atoms in tetrahedral geometry. The mean Zn (Ⅱ)- Cl bond length is 2. 264(1) A.     

Synthesis and Crystal Structure of Bis[O, O '-bis(4-tert-butylphenyl)dithiophosphate] nic kel(Ⅱ)

A new O,O'-bis(4-tert-butylphenyl)dithiophosphate complex Ni[SSP(OC6H4But- p)2]2 (1) was synthesized and characterized by elemental analysis, IR, 1H NMR, thermogravimetric analysis (TGA) and single-crystal X-ray diffraction. The crystal belongs to the monoclinic system, space group P21/c with a = 12.8440(3), b = 6.18686(12), c=26.3018(5) , β=92.6135(18)°, V = 2087.87(7) 3, Z = 2, Dc = 1.345 g/cm3, μ = 0.780 mm-1, the final R = 0.0316 and wR = 0.0748 (Ⅰ >2σ(Ⅰ)). A total of 4269 unique reflections were collected, of which 3621 with Ⅰ > 2σ(Ⅰ) were observed. The NiII atom lies on an inversion center and is chelated by two (p-ButC6H4O)2PSS-ligands in a [NiS4] square-planar geometry with Ni-S bonds of 2.2408(5) and 2.2444(5) , respectively. A stepwise 1D chain structure is constructed via intermolecular S…S and C-H…S interactions. According to our knowledge this is the first case that intermolecular S…S interaction is observed in mononuclear transition metal complex of O,O'-dialkyldithiophosphates.     

SYNTHESIS AND STRUCTURE OF Ni_2(PBu_3~n)_2(SC_7H_6S)_2

<正> The nickel(Ⅱ) complex Ni2(PBu3n)2(tdt)2(tdt = SC7H6S2-) containing dithiolato and phosphino ligands has been prepared and characterized by X-ray diffraction. The complex crystallizes in triclinic system, space group P1, with a = 14. 423(4), b = 15. 053(3), c=10. 648(3)(?), α=93.,95(2), β=100. 31(3), γ = 84. 16(2)°; V =2259.6 (?)3; Z = 2, Dc= 1. 22 gem-3, Mr = 830. 57; μ = 11. 076cm-1, F (000) = 888. In the complex, the Nickel atoms are linked by two bridging sulfur atoms from the two tdt ligands with the Ni-Ni distance of 2. 679 (?) . and each nickel atom is four coordinated by one phosphorus and three sulfur atoms with a square-planar geometry, the average length of Ni -S bond is 2. 193(?) and that of Ni-P bond 2.186(?).     

Hydrothermal Synthesis and Crystal Structure of a Novel Binuclear Cd(Ⅱ) Coordination Polymer Based on 1,2-Benzenedicarboxylate and Imidazole

The hydrothermal reaction of Cd(OAc)2·H2O with 1,2-benzenedicarboxylate(1,2-BDC),imidazole and H2O resulted in the formation of a binuclear polymeric Cd(Ⅱ) complex {[Cd2(1,2-BDC)2(Im)4]·(H2O)}n which was then characterized by elemental analyses and single-crystal X-ray diffraction analysis.The crystal is of monoclinic system,space group P21/c with a = 14.6455(3),b = 9.3530(2),c = 23.7838(5) ,β = 106.6290(10)°,C112H104Cd8N32O36,Mr = 3373.47,V = 3121.64(11) 3,Dc = 1.795 g/cm3,F(000) = 1672,μ = 1.428 cm-1 and Z = 1.The final R = 0.0316 and wR = 0.0687 for 5045 reflections with I > 2σ(I).In the title complex,the two Cd(Ⅱ) ions are in different coordination environments with distorted octahedral and pengonal bipyramidal geometries,respectively.Two Cd polyhedra are linked together through one μ2-η1:η1 and one μ2-η1:η2 carboxylate groups from different 1,2-BDC ligands,giving rise to a binuclear Cd(Ⅱ) cluster,and such clusters are connected by bridged 1,2-BDC ligands to form a 2-D structure along the c axis.The inter-and intermolecular hydrogen bonds further connect the 2-D structures into a 3-D supramolecular network.     

Synthesis, Crystal Structure and Antimicrobial Activity of a Novel Ni(Ⅱ) Complex

A new nickel(Ⅱ) complex, C34H38N8NiO4, has been prepared and charac-terized by X-ray diffraction analysis. It crystallizes in the monoclinic system, space group P21/c with a = 11.715(5), b = 12.328(5), c =11.113(5) A, β= 92.589(5)°, Z = 2, Dc = 1.411 g/cm3, μ = 0.658 mm-1, the final R = 0.0427 and wR = 0.1099 for 2229 observed reflections with Ⅰ> 2σ(Ⅰ). The complex is a centrosymmetric plane in which nickel(Ⅱ) is coordinated in a regular octahedron to the ligand phenytoin through the nitrogen atoms of ethylenediamine, imine and amine. The complex was valued for its antimicrobial activity against bacterial strands using the agar diffusion method, and found to be active against the four test bacterial organisms. Preliminary screening for antimicrobial activities showed that the title complex is quite active against standard strains of Salmonella species, Staphylococcus aureus, Bacillus pumilus and Eschierichia coli.     

Synthesis and Crystal Structure of a Dinuclear Complex： Bis[aqua（phen）（4- aba）copper（Ⅱ）nitrate（4-abaH）dihydrate]

The title complex has been obtained by the reaction of copper nitrate tri-hydrate with 4-abaH (4-abaH=4-aminobenzonic acid) and phenanthroline in ethanol solution,and its structure was determined by X-ray crystallography with the following data: monoclinic,space group C2/c,Mr=1266.13,Cu2C52H54N10O20,a=25.884(5),b=10.205(2),c=20.849(4) ,β=106.34(3)°,Z=4,V=5284.7(18) 3,F(000)=2616,Dc=1.591 g/cm3,μ=0.896 mm-1,the final R=0.0441 and wR=0.1148 for 4200 observed reflections (I > 2σ(I)). In the molecule of the title complex,the asymmetric unit contains one half molecule. The Cu(Ⅱ) atom is five-coordinated by a terminal water molecule,a bidentate phenanthroline and two monodentate 4-aminobenzoate ligands forming a square pyramidal coordination environment. The two bridging 4-aminobenzoate ligands result in a dinuclear copper(Ⅱ) cluster with a short Cu–Cu distance (3.048 ) and a π-π stacking between the adjacent phenanthroline rings (2.96 ).