Central Cu2 Research Articles

Polynuclear copper(II) complexes with hexadentate Schiff base directed by the counter ion. Syntheses, crystal structures and magnetic properties

Abstract Four new complexes, [Cu 9 L 6 ( µ 3 -ClO 4 ) 2 ](ClO 4 ) 4 ·4CHCl 3 1 , [Cu 3 L 2 (H 2 O) 2 ](ClO 4 ) 2 ·3H 2 O 2 , [Cu 6 L 4 (N 3 ) 2 ](ClO 4 ) 2 3 and [Cu 2 L(CH 3 COO) 2 ] 4 , where H 2 L stands for the Schiff base N , N ′-bis[(2-hydroxybenzilideneamino)-propyl]-piperazine, were obtained and structurally characterized. Compounds 1 , 2 and 3 contain the Cu 3 L 2 2+ entities in which L 2− acts in an unsymmetrical mode with N 3 O donor set wrapped around marginal copper(II) and with the remained NO sets bound to the central copper ion. The marginal copper(II) ions are in distorted square pyramidal environment, whereas that of the central one is square planar. In 1 , the peripheral copper(II) ions (Cu1) are disposed linearly with a two-fold axis passing through the central Cu2 and with the Cu1⋯Cu2 and Cu2⋯Cu1′ distances of 6.755 A. The linear trinuclear units are bridged by a rare µ 3 -1,2,3 perchlorate ligand thus describing a 2D network. In [Cu 3 L 2 (H 2 O) 2 ](ClO 4 ) 2 ·3H 2 O, the Cu 3 L 2 2+ unit is capped by two water molecules. Here, due to the intramolecular hydrogen bonds, the metal ions are disposed in the corner of a triangle with the Cu1⋯Cu2, Cu1⋯Cu3 and Cu2⋯Cu3 distances of 5.976, 5.314 and 5.760 Ǻ, respectively. In [Cu 6 L 4 (N 3 ) 2 ](ClO 4 ) 2 , two Cu 3 L 2 2+ units are bridged by two azido groups thus forming a macrocycle of six copper(II) ions. In [Cu 2 L(CH 3 COO) 2 ], L 2− acts as a symmetrical binucleatig ligand through the two N 2 O sets disposed on each side of the piperazine ring and pointed away in opposite directions. The square pyramidal environment of copper is achieved by chelate acetato co-ligand.

Synthesis, crystal structure, thermal decomposition, and XPS studies of homo and heterotrinuclear Cu(II)–Cu(II)–Cu(II) and Cu(II)–Ni(II)–Cu(II) complexes obtained from salpn type ligands

In this study, a mononuclear CuL complex was prepared by the use of bis-N,N′-(salicylidene)-1, 3-propanediamine (LH2) and Cu2+ ion. NiCl2 and NiBr2 salt were treated with this complex in dioxanewater medium and two new complexes [(CuL)2NiCl2(H2O)2] and [(CuL)2NiBr2(H2O)2)] with Cu(II)–Ni(II)–Cu(II) nucleus structure were obtained. In addition to this bis-N,N′-(2-hydroxybenzyl)-1,3-diaminopropane (LHH2) was prepared by the reduction of LH2 with NaBH4 in MeOH medium. The treatment of this reduced complex with Cu2+ ion resulted a complex [(CuLH)2CuCl2] with a structure of Cu(II)–Cu(II)–Cu(II). The complexes prepared were characterized by the use of elemental analysis, IR spectroscopy, thermogravimetric and X-ray diffraction methods. The crystal structures of [(CuL)2NiBr2(H2O)2] (СIF file CCDC 1448402) and [(CuLH)2CuCl2] (СIF file CCDC 1448401) complexes were elucidated. It was found that halogen ions are coordinated to terminal Cu2+ ions which are in a distorted square pyramid coordination sphere. It was determined that the central Cu(II), which joins terminal square pyramidal Cu(II), was coordinated only by the phenolic oxygens of the ligand while the central Ni(II) was coordinated by two phenolic oxygens of the organic ligand and two water molecules. These complexes were investigated by XPS and it was found that the terminal and central Cu2+ ions were different in Cu(II)–Cu(II)–Cu(II) complex. Also, the thermal degradation of the CuLH complex unit was observed to exothermic in contrast to the expectations.

Structural analyses of two new highly distorted octahedral copper(II) complexes with quinoline-type ligands; Hirshfeld, AIM and NBO studies

The structural features of two new copper(II) nitrato complexes with 3-bromoquinoline, [Cu(3BrQ)2(NO3)2] (1), and 6-methylquinoline, [Cu(6MeQ)2(NO3)2] (2), were investigated using X-ray single crystal structure determination, combined with Hirshfeld topology analysis of the molecular packing. Both complexes consist of two quinoline ligands and two bidentate nitrate ions hexa-coordinating the central Cu2+ atom. The major difference is that the Br-substituted quinoline ligands adopt trans positions, while the methyl-substituted ligands are in cis positions to one another. The packing arrangements of both ligands contain one-dimensionally infinite strings of complex molecules due to π–π stacking of neighboring ligand molecules. These strings are held together by C–H/O, Br–H/O and H–H/O contacts. The nature and strength of the Cu–N and Cu–O bonds were investigated using quantum theory of atoms in molecules (QTAIM) and natural bond orbital (NBO) analyses. Based on the QTAIM topological parameters, the Cu–N and Cu–O bonds have covalent nature where shorter Cu–O/Cu–N bonds are more covalent. Natural charges indicated a transfer of negative charge from the ligand groups to the Cu atom. The 6MeQ ligand transferred a larger amount of electron density to the Cu metal than 3BrQ. NBO analysis of the Cu2+ antibonding orbitals included in the metal–ligand interactions have mixed dx2-y2 and s-atomic orbital characters for 1, while in 2 they have mixed s and p-characters.

Two new complexes based on 2-(dinitromethylene)-1,3-diazacyclopentane (DNDZ): Synthesis, crystal structure and properties

Two new energetic complexes, Zn(NH3)2(DNDZ)2 and Cu(NH3)2(DNDZ)2 [DNDZ=2-(dinitromethylene)-1,3-diazacyclopentane], were first synthesized and structurally characterized. Zn(NH3)2(DNDZ)2 crystallizes in tetragonal crystal system with space group P4(1)2(1)2, but the crystal of Cu(NH3)2(DNDZ)2 is monoclinic with space group of C2/c. Zn2+ ion is coordinated by four N atoms from two NH3 molecules and two DNDZ− anions to form a distorted tetrahedron structure in Zn(NH3)2(DNDZ)2, while central Cu2+ ion coordinates with two O atoms and two N atoms from two DNDZ− anions and two N atoms of two NH3 molecules to form a six-coordinated octahedral structure in Cu(NH3)2(DNDZ)2. The thermal decomposition behaviors of the two complexes were studied with DSC and TG/DTG methods. Self-accelerating decomposition temperatures and critical temperatures are 164.7 and 166.4°C for Zn(NH3)2(DNDZ)2, and 149.6 and 150.8°C for Cu(NH3)2(DNDZ)2, respectively. The impact and friction sensitivities are >17.0J and 36% for Zn(NH3)2(DNDZ)2, and >10.0J and 56% for Cu(NH3)2(DNDZ)2, respectively. The two complexes exhibit lower sensitivity than analogous FOX-7 complexes.

Synthesis, structure and magnetic properties of a binuclear copper(II) complex constructed by a new coordination mode of the tetrachlorophthalate ligand

Abstract A binuclear complex [Cu2(tcpa)2(bipy)2(H2O)3] (1) (H4tcpa = tetrachlorophthalic acid, bipy = 2,2′-bipyridine) has been synthesized and structurally characterized. Two independent CuII centers Cu1 and Cu2 are both five-coordinated in distorted square pyramids. The tetrachlorophthalate (tcpa2–) anions show a new coordination mode: one is monodentate at Cu1, and the other displays a bridging μ 2-O,O″ fashion linking Cu1 and Cu2, thus forming the binuclear structure of 1. Variable-temperature magnetic susceptibility data show weak antiferromagnetic coupling between the two CuII ions.

2D Compound Constructed by Cu3 Units with Mixed Azido and Tetrazole Double Bridges: Synthesis, Structure, and Theoretical Study on Magnetic Properties

AbstractThe two‐dimensional (2D) layer CuII compound [Cu3(L)2(N3)4] (1) [L = 2‐amino‐3‐(5‐tetrazole)‐methyate‐N‐pyridine] was synthesized by in‐situ hydrothermal reaction of CuCl2·2H2O, NaN3, and 3‐(5‐tetrazole)‐methyate‐N‐pyridine. The central Cu1 and Cu2 atoms are located in five‐coordinate and six‐coordinate arrangements, respectively. Three CuII ions are linked by mixed double EO (end‐on)‐azido‐tetrazole bridges to give trinuclear CuII clusters, which are further extended by EE (end‐to‐end) azido bridges to form 2D metal‐organic layers. The magnetic exchange interactions in complex 1 were investigated by DFT calculations, and the calculated exchange interaction (J = –849 cm–1) revealed that the double EO‐azido‐tetrazole bridges transmit antiferromagnetic coupling between CuII ions.

High-order Cu(II) chloro-complexes in LiCl brines: Insights from density function theory and molecular dynamics

Cu(II) complexation by chloride is relevant to the transport of copper in near-surface geologic environments, yet the existence of high-order Cu(II) chloro-complexes still remains in dispute. In this study, the structure characteristics and stabilities of [CuClx]2−xaq (x=3, 4, 5) complexes have been investigated using density functional theory (DFT) methods and molecular dynamics (MD) simulations. [CuCl3]− and [CuCl4]2− species can both be tracked, while the [CuCl5]3−aq complex cannot be recorded during MD simulations of trace Cu2+ in chloride-rich brines. DFT calculations indicate that contact ion pair (CIP) conformers of [CuCl3]− species are less stable than its solvent separated ion pair (SSIP) conformers, in which one Cl− stays in the second coordination sphere of the centered Cu2+. MD simulations also reveal that the SSIP conformer is apt to appear in the aqueous solution than its CIP conformer. It seems that the third Cl− is more likely in the second coordination shell of center Cu2+ in [CuCl3]−. Meanwhile, the characteristic peak around 385nm resolved in UV–Vis spectra experiments, which was attributed to the [CuCl3]− complex, could also be resulted from some SSIP structures of the [CuCl3]− complex. In MD simulations, the complex [CuCl4]2−aq is found more stable than [CuCl3]−aq. The surrounding water molecules around [CuClx]2−xaq (x=3, 4) enhance their stabilities in Cl− brines, especially for [CuCl4]2−aq. The hydration shell of [CuCl4]2−aq species is more intact than that of [CuCl3]2−aq, and the residence time of a water molecule in the second coordination sphere of Cu ion in the [CuCl4]2−aq complex is also obviously longer than that of [CuCl3]−aq. The [CuCl4]2−aq complex can even be recorded in the less concentrated (6.33m)Cl− solution, while the [CuCl3]−aq complex is tracked only in the 16.32mCl− brine. Meanwhile, the possibilities of [CuCl3]−aq and [CuCl4]2−aq complexes found in 16.32mCl− solutions both decrease with increasing temperature, [CuCl3]−aq cannot be recorded during our simulations at 373K and 423K, and only few [CuCl4]2−aq at 423K.

Description of spin-crossover in a heterogeneous chain of exchange clusters

Spin transition theory is developed for periodic chains with two and more exchange clusters in a unit cell. A general expression is obtained for the effective magnetic moment of a unit cell μeff with several exchange clusters. For heterospin complexes Cu(hfac)2LR characterized by chains with the head-to-head motif a twosite approximation for the statistical sum of the Cu2+ Jahn-Teller paramagnetic center Cu2+ with spin 1/2 is proposed, within which a comparison with the available experimental data is performed. It is shown that the model developed describes both smooth and abrupt (cooperative) spin-crossover cases for the chains of three-spin exchange clusters.

Complexes with Hybrid Phosphorus-NHC Ligands: Pincer-Type Ir Hydrides, Dinuclear Ag and Ir and Tetranuclear Cu and Ag Complexes

Three types of hybrid phosphorus-imidazolium salts, 1-methyl-3-(3-((diphenylphosphino)methyl)benzyl)-1H-imidazol-3-ium hexafluorophosphate (2·PF6), 1-methyl-3-(3-(di-tert-butylphosphinooxy)phenyl)imidazolium iodide (8a), and 3-(3-((diphenylphosphoryl)methyl)phenyl)-1-methyl-1H-imidazol-3-ium iodide (11) have been prepared and used as precursors to phosphine-NHC, phosphinite-NHC, and phosphoryl-NHC metal complexes, respectively. The structure of 11 has been determined by X-ray diffraction. The Ag(I) and Ir(I) complexes of the phosphine-NHC ligand, [Ag(μ-P-NHC,κC,κP)]2(PF6)2 (3) and [Ir(cod)(μ-P-NHC,κC,κP)]2(PF6)2 (4), were obtained and characterized by NMR, ESI-MS, elemental analysis, and X-ray diffraction. Both complexes are dinuclear and dicationic, with two P-NHC ligands bridging the two metal centers. The presence of the P donor led for 3 to an unprecedented structure compared to that of related Ag(I) complexes with trans spanning bis-NHC ligands. Complex 4 is the first example of a dinuclear iridium complex with a hybrid P-NHC ligand. The new hydrido, Ir(III) pincer-type complex [IrH(CNHCCCNHC)(MeCN)]PF6 (7) is suggested to have a square-pyramidal structure. The tetranuclear Ag(I) complex with the phosphinite-NHC ligand, [Ag2(μ3-I)(μ-PO-NHC,κP,κCNHC)]2 (9a) has a cubane-type structure, with alternating silver and iodine apexes and two PO-NHC ligands bridging opposite edges of the Ag4 tetrahedron. The Ir(III) pincer complexes [IrH(I)(PO-NHC,κP,κC,κCNHC)(Me)] (10a) and [IrH(I)(PO-NHC,κP,κC,κCNHC)(n-Bu)] (10b), with Me or n-Bu substituents on the nitrogen atom, respectively, have been prepared and characterized. Ag(I) and Cu(I) complexes with the phosphoryl-NHC ligand are reported and the centrosymmetric structure of the latter, [Cu(OP-NHC,κCNHC)2(μ-I){Cu(μ-I)}]2 (13), was established by X-ray diffraction and consists of a central Cu2(μ-I)2 rhombus connected by single iodide bridges to two Cu(OP-NHC,κCNHC)2 moieties. The Ir(III) hydride pincer complexes 10a,b were tested as catalyst precursors for the C-H bond activation of alkanes. Although their efficiency was significantly lower for transfer dehydrogenation from cyclooctane (coa) to t-butylethylene (tbe) than that of known PCP-Ir systems, these results represent the first attempts to study the catalytic properties of hybrid P-NHC iridium pincer complexes.

Influences on the Aquathermolysis of Heavy Oil Catalyzed by Two Different Catalytic Ions: Cu2+and Fe3+

Two efficient viscosity reducers with the same ligand and different catalytic centers (Cu2+ and Fe3+) were prepared and characterized by Fourier transform infrared spectroscopy (FT-IR), and then used in catalytic aquathermolysis of six heavy oils. After that, Shengli extra-heavy oil (1.8 × 105 mPa s at 50 °C) was selected as the research object for an in-depth study of the same and different influences on the aquathermolysis of heavy oil catalyzed by the two catalytic ions. The compositions and structure of oil sample before and after reaction were analyzed by elemental analysis (EL), 1H nuclear magnetic resonance (1H NMR), gel permeation chromatrography (GPC), and gas chromatography–mass spectrometry (GC–MS). The corresponding structural parameters were calculated on the basis of the improved Brown–Ladner methods. The compared results showed that the two catalytic ions mainly acted on the asphaltene of oil sample. In addition, the former mainly caused the depolymerization and cleavage of some bridge bond...

Yaroshevskite, Cu9O2(VO4)4Cl2, a new mineral from the Tolbachik volcano, Kamchatka, Russia

AbstractA new mineral, yaroshevskite, ideally Cu9O2(VO4)4Cl2, occurs in sublimates collected from the Yadovitaya fumarole at the Second scoria cone of the Northern Breakthrough of the Great Tolbachik Fissure Eruption, Tolbachik volcano, Kamchatka, Russia. It is associated with euchlorine, fedotovite, hematite, tenorite, lyonsite, melanothallite, atlasovite, kamchatkite and secondary avdoninite, belloite and chalcanthite. Yaroshevskite forms isolated prismatic crystals, up to 0.1 × 0.15 × 0.3 mm in size, on the surface of euchlorine crusts. The mineral is opaque and black, with a reddish black streak and lustre between metallic and adamantine. Yaroshevskite is brittle, no cleavage was observed and the fracture is uneven. The Mohs hardness is ~3½ (corresponding to a mean VHN micro-indentation hardness of 172 kg mm -2) and the calculated density is 4.26 g cm-3. In reflected light, yaroshevskite is grey with a weak bluish hue. Pleochroism, internal reflections and bireflectance were not observed. Anisotropy is very weak. The composition (wt.%) determined by electron microprobe is: CuO 61.82, ZnO 0.53, Fe2O30.04, V2O531.07, As2O50.32, MoO31.56, Cl 6.23, O=Cl21.41; total 100.16. The empirical formula, calculated on the basis of 20 (O + Cl) anions is (Cu8.80Zn0.07Fe0.01)Σ 8.88(V3.87Mo0.12As0.03)σ 4.02O18.01Cl1.99. Yaroshevskite is triclinic, space groupP,a= 6.4344(11),b= 8.3232(13),c= 9.1726(16) Å , α = 105.338(14), β = 96.113(14), γ = 107.642(1)°,V= 442.05(13) Å3andZ= 1. The nine strongest reflections in the X-ray powder pattern [dobs in Å (I)(hkl)] are as follows: 8.65(100)(001); 6.84(83)(01); 6.01(75)(100); 5.52(60)(01); 4.965(55)(011); 4.198(67)(1); 4.055(65)(110); 3.120(55)(021); 2.896(60)(21,003,20). The crystal structure was solved by direct methods from single-crystal X-ray diffraction data and refined toR= 0.0737. The yaroshevskite structure is unique. It is based on corrugated layers made up of chains of edge-sharing flat squares with central Cu2+cations [Cu(1), Cu(4) and Cu(5)]; neighbouring chains are connected via groups consisting of three Cu2+-centred squares [two Cu(3) and Cu(6)]. Neighbouring layers are connected via pairs of Cu(2)O4Cl five-coordinate polyhedra and isolated VO4tetrahedra. The structure of yaroshevskite can also be considered in terms of oxygen-centred tetrahedra: O(7)Cu4tetrahedra are connected via common Cu(4) and Cu(5) vertices to form pyroxene-like chains [O2Cu6]∞. In this context, the structural formula can be written Cu3[O2Cu6][VO4]4Cl2. The mineral name honours the Russian geochemist Alexei A. Yaroshevsky (b. 1934) of Moscow State University.

Theoretical studies on the local structure and spin Hamiltonian parameters for the orthorhombic Cu2+ center in LiNbO3

The local structure and spin Hamiltonian parameters (the g factors and the hyperfine structure constants) for the orthorhombic Cu2+ center in LiNbO3 are theoretically studied from the perturbation formulas of these parameters for a 3d9 ion in an orthorhombically elongated octahedron. This center is ascribed to Cu2+ occupying the Nb5+ site in LiNbO3, associated with one nearest neighbour oxygen vacancy VO along the Z axis. The planar bond lengths are found to suffer the relative variation of about 0.16Å by compressing and stretching the Cu2+–O2− bonds along the X and Y axes, respectively, due to the Jahn–Teller effect and the charge mismatching substitution of Nb5+ by Cu2+. Meanwhile, the effectively positive VO can make the central Cu2+ displace away from the VO along the Z axis by about 0.3Å. The theoretical spin Hamiltonian parameters based on the above local distortions show good agreement with the experimental data.

N-bonding vs. S-bonding in thiocyanato-copper(II) complexes

Abstract Three mononuclear thiocyanato-Cu(II) complexes have been synthesized: the mono-thiocyanato [Cu(cyclen-tpam)(NCS)]ClO4·3H2O (1) and [Cu(DPA)(NCS)ClO4] (2), and the dithiocyanato complex Cu(bdmpzpy)(NCS)2 (3), where cyclen-tpam = 1,4,7,10-tetrakis(propionamide)-1,4,7,10-tetraazacyclododecane, DPA = bis(2-pyridylmethyl)amine, and bdmpzpy = 2,6-bis[(2,5-dimethyl-1-pyrazolyl)methyl]pyridine. The single crystal X-ray crystallography of the complexes confirmed the perfect square pyramidal geometry (SP) in 1 and distorted SP geometry in 2 and 3 with N-bonding coordination mode for the thiocyanato ligands. The IR spectra of the complexes which were consistent with the N-bonding coordination mode of the thiocyanate group(s) and the visible spectra which revealed the square pyramidal geometry around the central Cu2+ ion were in complete agreement with the X-ray structural determination.

Crystal structure and activity of a new Cu(II) complex with O...Cu weak interaction

A new CuL2 (HL = α-hydroxyacetophenone) complex is synthesized and investigated by elemental analysis, IR, UV-Vis, and X-ray diffraction. The complex crystallizes in the orthorhombic space group Pbca, a = 14.595(3) A, b = 12.517(3) A, c = 15.474(3)A, V = 2826.88(1) A3, Z = 4. The title complex has a square-planar geometry around the central Cu2+ ion. Two molecules form a dimer via a weak Cu1...O3 interaction, and the neighboring dimers of molecules are connected into a 2D structure through two very weak C-H...O interactions. The title complexes has high activity of killing pine wood nematodes.

Synthesis and crystal structure of a coordination polymer {[Cu2(L)2(Phen)2] · 8H2O} n

A novel metal coordination polymer, {[Cu2(L)2(Phen)2] · 8H2O} n (I), has been synthesized by the reaction of Cu(NO3)2 with 2,2′-bipyridyl-4,4′-dicarboxylic acid (L) and 1,10-phenanthroline (Phen) at room temperature. The polymer was characterized by IR, elemental analyses and X-ray diffraction. Single-crystal structural analysis reveals that the center Cu2+ ions have two coordinated types. The Cu(1) atom has the five-coordinate mode, and Cu(2) forms an is octahedron of the six-coordinate mode. Two Cu2+ ions are connected by the O atom of carboxylate group bridges. Complex I contains eight molecules of water clusters and constructed a 1D tape structure.

A Triple‐Decker Heptadecanuclear (CuII)15(CrIII)2 Complex Assembled from Pentanuclear Metallacrowns

AbstractReaction of the pentanuclear CuII metallacrown [Cu5(ahpha)4](ClO4)·4H2O (ahpha2– is the dianion of 3‐amino‐3‐(hydroximino)propanehydroxamic acid), with Cr(C2O4)33– led to the formation of a heptadecanuclear complex {[Cu5(ahpha)4]3[Cr(C2O4)3]2·4H2O}·8H2O·1/3(DMF) (1·8H2O·1/3(DMF)). This compound contains three stacked Cu5(ahpha)42+ building blocks, linked by axial bonds between Cu2+ ions of one Cu5 metallacrown and hydroxamate oxygen atoms of the neighboring Cu5 unit. Two Cr(C2O4)33– anions are bonded to the two lateral Cu5(ahpha)42+ cations through axial Cu–O(oxalate) bonds. The formation of 1 may be considered the first example of metallacrown trimerization caused by anion metathesis. The compound contains 10 × 13 Å voids (about 25 % of crystal volume), filled with solvate water molecules. The magnetic properties (χMT vs. T) could be fitted as the superposition of the magnetism of 3χMT(CuII5) and 2χMT(CrIII). Exchange interactions within the CuII5 units were fit in the framework of a model based on the Hamiltonian H(CuII5) = –2J1(S1.S5 + S2.S5 + S3.S5 + S4.S5) –2J2(S1.S2 + S2.S3 + S3.S4 + S4.S1), where S5 represents the central Cu2+ ions' spins and the other spin operators correspond to the peripheral Cu2+ ions. With other possible interactions taken into account using a molecular field approach, the best fit correspondedto J1 = –153(5) cm–1, J2 = –71(2) cm–1 and zJ′ = –0.058(4) cm–1.

Thiocyanato-copper(II) complexes derived from a tridentate amine ligand and from alanine

Two thiocyanato-Cu(II) complexes including mononuclear dithiocyanato Cu(Me3dpt)(NCS)2 (1) and the polymeric 1D [Cu(d,l-Ala)(μN,S–NCS)(H2O)] n (2) were synthesized and structurally characterized (Me3dpt = bis(N-methyl-3-propyl)methylamine, Ala = alaninate anion). The IR spectrum of complex 1 confirmed the N-bonding coordination mode of the thiocyanate groups, and its visible spectrum revealed the square pyramidal geometry around the central Cu2+ ion. Single X-ray crystallography of 1 showed that the Cu(II) center displays square pyramidal geometry with severe distortion toward trigonal bipyramidal environment. Complex 2 forms a 1-D polymeric chain with the NCS− acting as a μN,S-ligand. A distorted SP geometry around the Cu2+ centers was achieved by the O and N atoms of alaninato anion, the aqua ligand and by the N and S atoms of the bridging thiocyanate groups. Hydrogen bonds of the type N–H···O, N–H···S and O–H···O are formed in this complex leading to the extension of the 1D chain to a supramolecular network.

Synthesis and Crystal Structure of A Novel Mixed-valent Tri-copper Complex of 4′-p-Tolyl-2,2′:6′,2′-terpyridine

Two copper complexes of 4′-p-tolyl-2,2′:6′,2′-terpyridine (ttpy), namely, monomer [Cu II (ttpy)Cl2] (1) and trinuclear complex [Cu II (ttpy)Cl2]. [Cu II Cu I (ttpy)Cl3] (2), were prepared through solvothermal synthesis and structurally determined by single crystal X-ray diffraction. Compound 1 obtained by another way before was firstly solvothermally synthesized and structurally investigated herein. In 1 metal center Cu2+ ligated by a ttpy molecule and two chloride ions is in a distorted square pyramidal geometry. However, complex 2 is a novel mixed-valent tri-copper complex which contains a monomeric [Cu II (ttpy)Cl2] part being very similar to 1, and a mixed-valent chloride-bridged di-nuclear [Cu II Cu I (ttpy)Cl3] part, presented interesting co-crystallization behavior.

Catena-Poly[hemi[bis(4′-phenyl-2,2′:6′,2′′-terpyridine-κ3N)copper(II)] [cuprate(I)-di-μ2-thiocyanato-κ2N:S;κ2S:N

Reaction of 4′-phenyl-2,2′:6′,2′′-terpyridine (phtpy), copper acetate hydrate and ammonium thio­cyanate under solvothermal conditions led to the formation of the title compound, {[Cu(C21H15N3)2][Cu2(NCS)4]}n. The structure is composed of discrete [Cu(phtpy)2]2+ cations and polymeric anionic {[Cu(SCN)2]−} chains propagating along [010]. The central Cu2+ ion in the cation is coordinated by two tridentate chelating phtpy ligands in a distorted octa­hedral geometry. In each of the two crystallographically independent centrosymmetric anions, the CuI atoms are bridged in a 1,3-μ2-bridging mode by two S and two N atoms, resulting in a distorted tetrahedral CuN2S2 coordination. The [Cu(phtpy)2]2+ cations are fixed between these polymers by inter­molecular C—H⋯S hydrogen bonds.

One trinuclear copper(II) complex derived from a new Schiff base ligand based on the dianion of 4-chloro-6-(hydroxymethyl)-2-((3-aminopropylimino)methyl)-phenol: Synthesis, structure, spectroscopic and magnetic properties

Abstract A linear trinuclear copper(II) complex ( 1 ), prepared from a new Schiff base ligand, namely the dianion of 4-chloro-6-(hydroxymethyl)-2-((3-aminopropylimino)methyl)-phenol, was synthesized and characterized in this paper. The X-ray structural study reveals that the geometry of the central Cu2 ion is elongated octahedral and that of the two side Cu(II) ions is distorted square pyramidal. The magnetic susceptibility measurements from 2 to 300 K reveal medium antiferromagnetic interactions between the Cu(II) ions with a J value of −64.6(1) cm −1 .