Synthesis,Crystal Structure and Property of a Binuclear Copper Complex [Cu_2L_2(pht)_2]_2·H_2O

A new binuclear copper complex, [Cu2L2(pht)2]2·H2O(Hpht = 5,5-diphenylhydantoin, i.e. phenytoin; L = 2-diethylaminoethanol), has been synthesized by the solvothermal method, and characterized by elemental analysis, IR and single-crystal X-ray diffraction. The crystal belongs to the monoclinic system, space group C2/c with a = 31.918(3), b = 12.9222(15), c = 19.868(2) , β = 98.762(2)o, V = 8098.8(16) 3, Dc = 1.429 Mg/m3, Z = 4, F(000) = 3640, μ = 1.107 mm-1, R = 0.0560 and wR = 0.1276(I 2(I)). Each copper(Ⅱ) in a molecule is coordinated with N and O atoms from ligand L and N atom from ligand Hpht in a tetradentate manner. Moreover, two copper(Ⅱ) centers are bridged by two O atoms of hydroxyl groups from two L ligands to form a slightly distorted binuclear {Cu2O2} diamond configuration. In addition, the interaction of this complex with calf thymus DNA(CT-DNA) was investigated by UV-vis spectrum and viscometry, and the complex may bind to DNA through intercalation.     

Synthesis, crystal structure and magnetic properties of the binuclear copper (II) complex of a new bis (1, 4, 7,10-tetraazacyclodoclecane) ligand

A new binucleating macrocyclic ligand 2,6-bis (1,4,7,10-te-traazacyclododecan-10-ylmethyl)methoxy-benzene (L) and its binuclear copper (II) complex, [ Cu2LBr2 ] (ClO4 )2 · 3H2O (1), was prepared and the structure was determined by X-ray crystallography. Complex 1 crystallizes in monoclinic crystal system, P21/n space group with a = 0.8206(3), b = 2.0892(8), c = 2.3053(7) nm, β=95.83(2)°, V = 3.932 nm3, Mr = 1017.57, Z = 4, Dc= 1.692 g/cm3, and R = 0. 0489, Rw= 0.0552 for 6571 observed reflections with I≥2σ (I). Both of the copper(II) centers are coordinated by four amine nitrogen donors of cyclen subunits and a bromide an-ion, and each copper (II) ion is in a square-pyramidal coordination environment. Variable temperature magnetic susceptibility studies indicate that there exists weak intramolecular an-tiferro-magnetic coupling ( - 2J = 2.06 cm-1) between the two copper(n) centers.     

Hydrothermal Synthesis,Crystal Structure and Electrochemical Properties of a New Dinuclear Copper Complex [C2H6ON]2[Cu2Cl2（μ-CH3COO）4]

The hydrothermal reaction of copper chloride dihydrate and 5,5-dimethyl-imidazolidine,-2,4-dione with a mole ratio of 1：1 in acetonitrile resulted in the formation of a new acetate-bridged dinuclear copper complex, [C2H6ON]2[Cu2Cl2（μ-CH3COO）4]. Protonated acetamide in eaolie form and acetic acid were yielded by the hydrolysis of acetonitrile under hydrothennal condition. The rifle complex （C12H24Cl2Cu2N2O10） was characterized by X-ray single-crystal diffraction, IR spectrum, elemental and electrochemical analysis. It crystallizes in the monoclinic system, space group P21/c with a = 8.298004）, b = 14.358（2）, c = 12.0010（2） A^°, β= 130.620（3）°, V = 1085.3（2） A^°^3, Dc = 1.696 g/cm^3, 34, = 554.31, Z = 2, F（000） = 564 and μ = 2.254 mm^-1. The crystal structure consists of a tetraacetate-bridging dinulcear copper complex anion [Cu2Cl2（μ-CH3COO）4]^2-, with the chlorine anions in the axial positions, and two protonated acetamide cations [C2H6ON]^＋, which were connected through hydrogen bonds to form a three-dimensional infinite network.     

Theoretical Studies on the Spin Exchange Interaction in Copper（Ⅱ） Complexes Coordinated with Nitronyl Nitroxide

Nitronyl nitroxide radical 1, NIT (4, 4, 5, 5-tetramethyl-4, 5-dihydro-1H-imidazolyl-1-oxyl-3-oxide) and copper(Ⅱ) chloride complexes with nitronyl nitroxide 2, [Cu(NITPh)2Cl2](NITPh = 2-phenyl-4, 4, 5, 5-tetramethyl-imidazoline-1-oxyl-3-oxide) were studied with density functional theory (DFT). The magnetic orbital analysis reveals that the antiferromagnetic coupling for complex 2 is due to the antibonding σ^*-orbital overlap between dx^2-y^2 (Cu)and π^* (NO) orbitals. Also, spin population and atomic charge distribution analysis suggest that for AFS of complex 2 the antiferromagnetic coupling between the radical ligands and the copper(Ⅱ) ion originates from the spin delocalization induced by the a electron transfer from π^*(NO) to d^x2-y^2 (Cu) orbital.     

A New Dinuclear Cu(Ⅱ) Complex of a Ligand with Benzimidazole Group─Synthesis and Crystal Structure

A new dinuclear copper complex, [Cu(C9H11N3)Cl2]2 (C18H22Cl4Cu2N6), has been synthe- sized and characterized by X-ray structure determination. It crystallizes in the triclinic P1 space group with a = 7.526(3), b = 9.473(4), c = 9.535(3) , α = 117.214(10), β = 108.251(9), γ = 91.560(6)o, V = 562.3(4) 3, Z = 1, Mr = 591.30, F(000) = 298, Dc = 1.746 g/cm3, μ(MoKα) = 2.385 mm-1, the final R = 0.0577 and wR = 0.1248 for 2188 unique reflections with 1629 observed ones (I > 2σ(I)). In the title complex, each copper(II) atom is located at the center of a distorted trigonal bipyramid of five coordination atoms (two nitrogen and three chlorine atoms). Two copper(II) atoms were bridged by two chlorine anions (Cl(2) and Cl(2a)) to form a Cu(II)-Cu(II) binuclear entity with the distance between two copper(II) atoms of 3.398 .     

Crystal Structure and Properties of a Copper(Ⅱ) Complex Containing p-Toluenesulfonate and Imidazole Ligands

A novel supramolecular mixed ligand complex of formula [Cu(PTS)2(Him)2(H2O)2] (C20H26CuN4O8S2,PTS=p-toluenesulfonate,Him=imidazole) has been synthesized in aqueous solution and characterized by elemental analysis,IR and single-crystal X-ray diffraction.The compound crystallizes in the monoclinic system,space group P21/n,Z=2,a=5.650(2),b=14.671(3),c=14.638(3),β=100.10(3)°,V=1194.60(4)3,Dc=1.607 g/cm3,μ(MoKα)=1.143 mm-1,F(000)=598,R=0.0615 and wR=0.1503 for 1752 observed reflections with I 2σ(I).The copper(II) ion in the complex adopts a slightly distorted octahedral coordination geometry and is six-coordinated with N2O4 donor set consisting of two nitrogen atoms and four oxygen atoms provided by the ligands of two imidazole molecules,two water molecules and two p-toluenesulfonate ions.The sulfonate group of the PTS ligand remains weak-coordinated and forms a number of hydrogen bonds with water molecules and imidazole ligands.X-ray structural analysis reveals that the coordination molecules are connected to form a 3-D supramolecular framework by electrostatic interaction,weak van der Waals forces,hydrogen bonding and π-π interaction.The thermal behaviour of the title complex was investigated by using DSC and TG-DTG techniques.     

Synthesis, Crystal Structure and Antibacterial Activity of a New Ternary Copper（Ⅱ） Complex with 2,6-Pyridinedicarboxylic Acid and 1,10-Phenanthroline

A new ternary copper(II) complex,[C 43 H 27 Cu 2 N 7 O 5 ]·[C 14 H 6 CuN 2 O 8 ]·6.5H 2 O,has been synthesized by the reaction of copper sulfate,2,6-pyridinedicarboxylic acid and 1,10-phenanthroline (phen),and characterized by elemental analysis,IR,UV and X-ray single-crystal diffraction.It crystallizes in triclinic,space group P1,with a=14.379(5),b=15.510(5),c=15.835(6),α=78.567(6),β=63.594(6),γ=81.287(6)°,V=3092.1(19)3,C 57 H 46 Cu 3 N 9 O 19.5,M r=1359.54,Z=2,D c=1.446 Mg/m 3,λ(MoKα)=0.71073,μ=1.101 mm-1,F(000)=1362,S=1.071,the final R=0.0718 and wR=0.11960 for 10705 observer reflections (I > 2σ(I)).The structure unit of the title complex consists of a mononuclear part and a di-nuclear part,and the three copper ions show three coordination modes.Each 6-coordinated geometry of the Cu atom is a distorted octahedral coordination geometry.The 3D supramolecular system is formed by the hydrogen bond O-H···O and π-π stacking interaction between neighboring single cells.The antibacterial activity of the title complex is also studied.     

Synthesis and Crystal Structures of Two Di-Cu(Ⅱ) Complexes Based on an Asymmetric Dinucleating Ligand

Two new dicopper(II) complexes [Cu2L(OAc)2](ClO4)·H2O(1) and [Cu2L(BPP)2]-(ClO4)(2) using an asymmetric dinucleating ligand HL and auxiliary ligands such as acetate(OAc) and bisphenyl phosphate(BPP) have been synthesized and characterized by elemental analysis, IR and single-crystal X-ray diffraction. Complex 1 crystallizes as blue single crystals that belong to the triclinic crystal system and P1 space group, while complex 2 crystallizes in a monoclinic P21/c space group. Single-crystal X-ray diffraction analysis reveals that the two copper ions in complexes 1 and 2 reside within the adjacent ligand compartments and are bridged by the endogenous phenoxo-O from ligand L and the introduction of two desired exogenous carboxylates or phosphates in the bidentate μ-1,3-bridged mode. The coordination geometries of Cu(1) and Cu(2) are both distorted square pyramids.     

Synthesis and Characterization of Three Diverse Coordination Frameworks under Co-ligand Intervention

The chelating organic ligands of 2,2’-bipyridine (2,2’-bipy), di(pyrid-2-yl)amine (dpa) and 2,6-di(pyrid-2-ylamino)pyridine (dpap) were respectively applied to react with H2fum (fumaric acid) and copper salts, affording three different complexes [Cu2(fum)(2,2’-bipy)4]•2ClO4 (1), [Cu2(µ-OH)2(fum)(dpa)2]•2H2O (2) and [Cu(SO4)(H2O)(dpap)]•H2O (3). These complexes were determined by single-crystal X-ray diffraction. Each penta-coordinated Cu(II) ion exhibits a distorted trigonal bipyramidal geometry in 1. The fum ligand links copper ions to form a dinuclear copper unit. While in 2, the fum ligands connect [Cu2(µ-OH)2(dpa)2] unit to construct a 1D zigzag chain. Unexpectedly, when dpap instead of dpa was used under the same conditions, only one mononuclear complex 3 was formed. Crystal packings show that 1—3 form 3D supramolecular architectures through non-covalent interactions (multiple hydrogen bonds and C—H…π/π-π interactions). In addition, the study of the magnetic property reveals dominating ferromagnetic interactions between Cu(II) atoms in 1.     

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.     

Coordination behavior of 3,4-bis(2-pyridylmethylthio)toluene with copper(II) ions: Synthesis,structural characterization and reactivity,and DNA binding study of the dinuclear copper(II) complex

On reaction of different copper(II) salts with 3,4-bis(2-pyridylmethylthio)toluene (L) having neutral tetradentate NSSN donor set in different chemical environments, two mononuclear copper(II), one dinuclear copper(I) and one dinuclear copper(II) complexes, formulated as [Cu^II(L)(H₂O)₂](NO₃)₂ (1), [Cu^II(pic)₂] (2), [Cu^I₂(L)₂](ClO₄)₂ (3) and [Cu^II₂(L)₂Cl₂](ClO₄)₂ (4), respectively, were isolated in pure form [where pic = picolinate]. All the complexes were characterized by physicochemical and spectroscopic methods. The product of the reactions are dependent on the counter anion of copper(II) salts used as reactant and on the reaction medium. Complexes 1 and 4 were obtained with nitrate and perchlorate copper(II) salts, respectively. On the other hand, C–S bond cleavage was observed in the reaction of L with copper(II) chloride to form in situ picolinic acid and complex 2. Dinuclear complexes 3 and 4 were separated out when copper(II) perchlorate was allowed to react with L in methanol and in acetonitrile, respectively, under aerobic condition. The X-ray diffraction analysis of the dinuclear complex 3 shows a highly distorted tetrahedral geometry about each copper ion. Complex 4 is converted to 3 in acetonitrile in presence of catechol. The spectral study of complex 4 with calf thymus DNA is indicative of a groove binding mode interaction.     

Synthesis,Characterization and Crystal Structures of Four Dinuclear Schiff Base Nickel(II) and Copper(II) Complexes with Versatile Bridging Groups

Four novel Schiff base nickel(II) and copper(II) complexes, derived from the end‐on (μ_1,1‐N₃) azide, end‐to‐end (μ_1,3‐NCS) thiocyanate, or phenolate oxygen bridges, have been synthesized and their crystal structures determined by X‐ray diffraction methods. They are the dinuclear double end‐on azide‐bridged [Ni₂(L1)₂(MeCN)₂(μ_1,1‐N₃)₂]·MeOH ( 1 ), the dinuclear double end‐on azide‐bridged [Ni₂(L2)₂(MeOH)₂(μ_1,1‐N₃)₂][Ni₂(L2)₂(OH₂)₂(μ_1,1‐N₃)₂]·MeOH ( 2 ), the dinuclear double end‐to‐end thiocyanate‐bridged [Cu₂(L3)₂(μ_1,3‐NCS)₂] ( 3 ), and the dinuclear double phenolate O‐bridged [Cu₂(L4)₂(NCS)₂] ( 4 ), where HL1, HL2, HL3 and HL4 are four tridentate Schiff bases obtained by the condensation of 3,5‐dibromosalicylaldehyde with N‐ethylethane‐1,2‐diamine, of 3,5‐dichlorosalicylaldehyde with N‐methylpropane‐1,3‐diamine, of 3‐bromo‐5‐chlorosalicylaldehyde with 2‐aminomethylpyridine, and of 5‐nitrosalicylaldehyde with 2‐aminomethylpyridine, respectively. Each nickel(II) atom in 1 and 2 is in an octahedral coordination, while each copper(II) atom in 3 and 4 is in a square pyramidal coordination. There exists crystallographic inversion centre symmetry in each of the complexes.     

Synthesis,structural characterization and catalytic activities of dicopper(II) complexes derived from tridentate pyrazole‐based N2O ligands

A group of a diverse family of dinuclear copper(II) complexes derived from pyrazole‐containing tridentate N₂O ligands, 1,3‐bis(3,5‐dimethylpyrazol‐1‐yl)propan‐2‐ol (Hdmpzpo), 1,3‐bis(3‐phenyl‐5‐methyl pyrazol‐1‐yl)propan‐2‐ol (Hpmpzpo) and 1,3‐bis(3‐cumyl‐5‐methylpyrazol‐1‐yl)propan‐2‐ol (Hcmpzpo), were synthesized and characterized by elemental analysis, IR spectroscopy and three of them also by single‐crystal X‐ray diffraction. Three complexes, [Cu₂(pmpzpo)₂](NO₃)₂·2CH₃OH ( 3 ·2CH₃OH), [Cu₂(pmpzpo)₂](ClO₄)₂ ( 4 ) and [Cu₂(cmpzpo)₂](ClO₄)₂·2DMF ( 7 ·2DMF), each exhibits a dimeric structure with a inversion center being located between the two copper atoms. The metal ion is coordinated in a distorted square planar environment by two pyrazole nitrogen atoms and two bridging alkoxo oxygen atoms. Both complexes 1 ·CH₃OH·H₂O and 3 ·2CH₃OH were investigated in anaerobic conditions for the catalytic oxidation of 3,5‐di‐tert‐butylcatechol (3,5‐DTBC) to the corresponding quinone (3,5‐DTBQ), for modeling the functional properties of catechol oxidase. Copyright © 2007 John Wiley & Sons, Ltd.     

Syntheses,Crystal Structure,and Magnetic Properties of a Self‐assembling Dicopper(II) Helicate with Novel Bipyridine Ligand

A novel double helical dicopper(II) complex was synthesized by reaction of a polydentate ligand L = 2,2′‐bipyridyl‐6,6′‐bis(2‐acetylpyrazinohydrazone) with copper(II) perchlorate in CH₃CN. The self‐assembling process was studied by UV‐Vis spectrometric titration experiments which revealed the formation of dinuclear complexes [Cu₂L₂](ClO₄)₄. The structure of dicopper double‐helicate was confirmed by X‐ray diffractometry. Each copper(II) center occupies a distorted octahedral environment. Variable‐temperature magnetic measurements reveal weak antiferromagnetic interactions between Cu(II) ion centers with J = ?0.63 cm^?1.     

First Dinuclear Copper/Gallium Complexes: Supporting Cu0 and CuI Centres by Low‐Valent Organogallium Ligands

The synthesis and structural characterisation of low‐valent dinuclear copper(I) and copper(0) complexes supported by organogallium ligands has been accomplished for the first time by the reductive coordination reaction of [GaCp*] (Cp*=pentamethylcyclopentadienyl) and [Ga(ddp)] (ddp=HC(CMeNC₆H₃‐2,6‐iPr₂)₂ 2‐diisopropylphenylamino‐4‐diisopropylphenylimino‐2‐pentene) with readily available copper(II) and copper(I) precursors. The treatment of CuBr₂ and Cu(OTf)₂ (OTf=CF₃SO₃) with [Ga(ddp)] under mild conditions resulted in elimination of [Ga(L)₂(ddp)] (L=Br, OTf) and afforded the novel gallium(I)/copper(I) compounds [{(ddp)GaCu(L)}₂] (L=Br ( 1 ), OTf ( 2 )). The single‐crystal X‐ray structure determinations of 1 and 2 reveal that these molecules are composed of {(ddp)GaCu(L)} dimeric units, with planar Cu^I? Ga^I four‐membered rings and short Cu^I???Cu^I distances, with 2 exhibiting the shortest Cu^I???Cu^I contact reported to date of 2.277(3) Å. The all‐gallium coordinated dinuclear [Cu₂(GaCp*)(μ‐GaCp*)₃Ga(OTf)₃] ( 3 ) is formed when Cu(OTf)₂ is combined with [GaCp*] instead of [Ga(ddp)]. Notably, in the course of this redox reaction Lewis acidic Ga(OTf)₃ is formed, which coordinates to one of the electron‐rich copper(0) centres. Compound 3 is suggested as the first case of a structurally characterised complex of copper(0). By changing the copper(II) to a copper(I) source, that is, [Cu(cod)₂][OTf] (cod=1,5‐cyclooctadiene), the salt [Cu₂(GaCp*)₃(μ‐GaCp*)₂][OTf]₂ ( 4 ) is formed, the cationic part of which is related to previously described isoelectronic dinuclear d¹⁰ complexes of the type [M₂(GaCp*)₅] (M=Pd, Pt).     

Copper(II) complexes of tetradentate N2S2 donor sets: Synthesis,crystal structure characterization and reactivity

Two mononuclear and one dinuclear copper(II) complexes, containing neutral tetradentate NSSN type ligands, of formulation [Cu^II(L¹)Cl]ClO₄ (1), [Cu^II(L²)Cl]ClO₄ (2) and [Cu^II₂(L³)₂Cl₂](ClO₄)₂ (3) were synthesized and isolated in pure form [where L¹ = 1,2-bis(2-pyridylmethylthio)ethane, L² = 1,3-bis(2-pyridylmethylthio)propane and L³ = 1,4-bis(2-pyridylmethylthio)butane]. All these green colored copper(II) complexes were characterized by physicochemical and spectroscopic methods. The dinuclear copper(II) complex 3 changed to a colorless dinuclear copper(I) species of formula [Cu^I₂(L³)₂](ClO₄)₂,0.5H₂O (4) in dimethylformamide even in the presence of air at ambient temperature, while complexes 1 and 2 showed no change under similar conditions. The solid-state structures of complexes 1, 2 and 4 were established by X-ray crystallography. The geometry about the copper in complexes 1 and 2 is trigonal bipyramidal whereas the coordination environment about the copper(I) in dinuclear complex 4 is distorted tetrahedral.     

Altering the Activity of Catechol Oxidase Model Compounds by Electronic Influence on the Copper Core

The catecholase activity of the dicopper(II) complexes [Cu₂(L¹)(μ‐OCH₃)(NCCH₃)₂](PF₆)₂·H₂O·CH₃CN ( 1 ), [Cu₂(L²)(μ‐OH)(MeOH)(NCCH₃)](BF₄)₂ ( 2 ), [Cu₂(L³)(μ‐OMe)(NCCH₃)₂](BF₄)₂·2CH₃CN·H₂O ( 3 ), [Cu₂(L²)(μ‐OAc)₂]BF₄·H₂O ( 4 ), [Cu₂(L⁴)(μ‐OAc)₂]ClO₄ ( 5 ) and [Cu₂(L⁵)(μ‐OMe)(NCCH₃)₃(OH₂)](ClO₄)₂·2CH₃OH·CH₃CN ( 6 ) consisting of varying para‐substituted phenol ligands HL¹ = 4‐trifluoromethyl‐2,6‐bis((4‐methylpiperazin‐1‐yl)methyl)phenol, HL² = 4‐bromo‐2,6‐bis((4‐methyl‐1,4‐diazepan‐1‐yl)methyl)phenol, HL³ = 4‐bromo‐2‐((4‐methyl‐1,4‐diazepan‐1‐yl)methyl)‐6‐((4‐methylpiperazin‐1‐yl)methyl)phenol, HL⁴ = 2,6‐bis((4‐methylpiperazin‐1‐yl)methyl)‐4‐nitrophenol and HL⁵ = 4‐tert‐butyl‐2,6‐bis((4‐methylpiperazin‐1‐yl)methyl)phenol was studied. The main difference within the six complexes lies in the individual copper–copper separation that is enforced by the chelating side arms of the phenolate ligand entity and more importantly in the exogenous bridging solvent, hydroxide, methanolate or acetate ions. The distance between the copper cores varies from 2.94Å in 1 to 3.29Å in 5 . The catalytic activity of the complexes 1 – 6 towards the oxidation of 3,5‐di‐tert‐butylcatechol was determined spectrophotometrically by monitoring the increase of the 3,5–di‐tert‐butylquinone characteristic absorption band at about 400 nm over time saturated with O₂. The complexes are able to oxidize the substrate 3,5‐di‐tert‐butylcatechol to the corresponding o‐quinone with distinct catalytic activity (k_cat between 92 h^?1 and 189 h^?1), with an order of decreasing activity 6 > 5 > 1 , 2 , 4 ≥ 3 . A kinetic treatment of the data based on the Michaelis‐Menten approach was applied. A correlation of the catecholase activities with the variation of the para‐ substituents as well as other effects resulting from the copper core distances is discussed. [Cu₂(L⁵)(μ‐OMe)(NCCH₃)₃(OH)₂](ClO₄)₂·2CH₃OH·CH₃CN ( 6 ) exhibited the highest activity of the six complexes as a result of its high turnover rate.     

Nickel(II), Cadmium(II), and Copper(II) Complexes Based on Ditopic Terpyridine Derivative Ligand: Syntheses,Crystal Structures,and Luminescent Properties

Three complexes with the ditopic ligand 4′‐[4‐(quinolin‐8‐yloxymethyl)phenyl]‐2,2′:6′,2′′‐terpyridine (abbreviated as L ), [Ni(L)₂](CH₃COO)₂ ( 1 ), [Cd(L)₂](ClO₄)₂ ( 2 ), and [Cu₂(L)₂](ClO₄)₄ · 4DMF ( 3 ), were synthesized and characterized by elemental analysis, IR spectroscopy, and structurally analyzed by X‐ray single‐crystal diffraction. Interestingly, in complexes 1 and 2 , two ligands adopt a tridentate chelating pattern where the oxaquinoline group is non‐coordinated and coordinate with one M^II ion (M = Ni for 1 , M = Cd for 2 ) to form a mononuclear unit. In complex 3 , two ligands bridge two Cu^II ions by pyridyl N atoms, ethereal O atoms, and quinolyl N atoms in a head‐to‐tail mode to generate a dinuclear [Cu₂L₂] unit. Moreover, extended 1D and 2D supramolecular architectures are further constructed in 1 – 3 by multiple secondary interactions such as aromatic stacking and hydrogen bonding. Notably, the structural diversity of complexes 1 – 3 can be properly assigned to the central metal ions that have distinct coordination preferences. In addition, luminescent properties of the ligand and complex 2 were also investigated.     

Synthesis,Structural and Energetic Properties of Copper(II) Perchlorate Complex with Aminoguanidine

The complexation of copper(II) perchlorate with aminoguanidine hemesulfate (AGHS) yield related mononuclear complex bis(aminoguanidine)copper(II) perchlorate; [Cu(AG)₂](ClO₄)₂ ( I ). The characterization of complex I was done by elemental analysis, electronic spectra, IR studies, and X‐ray diffraction. From analytical data, a stoichiometry of 1:2 of metal to ligand was determined for the complex. The structure consists of centrosymmetric square planar [Cu(AG)₂]²⁺ cations and perchlorate counterions. The Cu^II atom is four‐coordinate by two imine N atoms and two amine N atoms from two aminoguanidine ligands, forming a slightly distorted square‐planar coordination. In the crystal structure, molecules are linked through intermolecular N–H ··· O hydrogen bonds, forming a network. The thermal decomposition process of this complex was investigated through differential scanning calorimetry (DSC) and the sensitivities toward impact and friction were assessed using a BAM drophammer and a BAM friction tester.