Two-dimensional nickel(II) tetraaza macrocyclic complex linked by hydrogen bonds

The complex [Ni(L)](PDC) 2H₂O (L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo[16,4, 0^1.18,0^7.12]docosane; PDC = 3,5-pyrazoledicarboxylate) has been synthesized and characterized by X-ray crystallography. It crystallizes in the monoclinic system P2₁/c with a = 9.739(4) Å, b = 10.491(3) Å, c = 16.884(3) Å, = 97.17(2)°, V = 1711.5(8) ų, Z = 4. The coordination environment around the nickel(II) ion exhibits a slightly distorted square-plane with four secondary amines of the macrocycle. The title compound is interconnected to give a two-dimensional network through the hydrogen-bonding interactions.     

Synthesis and characterization of copper(II) tetraaza macrocyclic complex with 2- benzimidazolepropionate ligand

A mononuclear complex [Cu(L)(bip)₂] (1) (L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo [14,4,0^1.18, 0^7.12]docosane; bip = 2-benzimidazolepropionate) has been synthesized and structurally characterized by X-ray crystal structure analysis. The crystals are monoclinic P2 ₁/n with a = 10.2990(2), b = 15.9400(3), c = 11.991(14) Å, = 101.92(7)°, V = 1926(2) ų, Z = 2. The copper(II) coordination geometry exhibits an axially elongated octahedron with four nitrogen atoms from the macrocycle and two oxygen atoms from the bip ligands. The cyclic voltammogram of 1gives 2 one-electron waves corresponding to Cu^II/Cu^III and Cu^II/Cu^I processes.     

Catenated molecular pattern in the crystal structure of a copper(II) complex with pyrazine-2,6-dicarboxylic acid and chloride ligands

The crystals of catena-dichloro-(dihydrogen pyrazine-2,6-dicarboxylato-O,O′,N,-N′) copper(II) dihydrate Cu[H₂(2,6-PZDC)]Cl₂?2H₂O are monclinic, space group C2/c with a = 11.658(2) Å, b = 6.778(1) Å, c = 16.390(3) Å, β = 98.90(3)^°, and Z = 4. Two adjacent copper(II) ions are bridged by a fully protonated pyrazine-2,6-dicarboxylic acid molecule which uses for bridging its O,O′,N-bonding moiety on one side and a single hetero-ring nitrogen atom on the other. Two chloride ions in axial position complete the octahedral coordination around the metal ions with bond distances: Cu–N 2.027(3) ÅA, Cu–N′ 2.005(3) ÅA, Cu–Cl. 2.281(1) ÅA, and Cu–O 2.446(2) ÅA. Copper(II) ions are located in the center of symmetry and are coplanar with the ligand acid molecule forming flat molecular chains propagating in the direction of the b axis. Hydrogen bonds via solvation water molecule link the chains into molecular layers parallel to the ac plane. Weak van der Waals type interactions operate between the layers.     

A novel four-coordinate zinc(II) complex of the di-N-hydroxypropylated tetraaza macrocycle

The compound [Zn(L²)Cl]ClO₄·H₂O (1) (L² = 2,13,-bis(3-hydroxypropyl)-5,16-di-methyl-2,6,13,17-tetraazatricyclo[14,4,0^1.18,0^7.12]docosane) has been synthesized and structurally characterized. 1 crystallizes in the monoclinic system, space group P2₁/c with a = 8.932(2), b = 16.189(2), c = 22.492(4) Å = 95.34(2)° V = 3238.3(11) ų; and Z = 4. The zinc atom is placed in a highly distorted tetrahedral environment bonding with three nitrogen atoms of the macrocycle and one chlorine atom.     

3-D polymeric structure formed by hydrogen bonds of copper (II) complex

A new copper complex trans-Dichlorobis[4-methoxypyridine]copper(II) (1) was synthesized and its crystal structure determined by X-ray diffraction. The close Cu···Cl contacts between the molecular units form bi-bridged dimers. The Copper(II) ion completes its 4 + 2 coordination via interaction with the Cu···Cl close contact. The complex has a polymeric structure of infinite one-dimensional (1D) bi-bridged chains, consisting of six-coordinate copper(II) units. C–H···C l intermolecular interaction connect the 1D-chains in the structure of 1 which form to 3D structure. The π ··· π interactions between the aromatic rings are also observed in the hydrogen bonded assembly of 1.     

Synthesis and crystal structure of a macrocyclic azidotetraamine copper(II) complex

The complex [Cu(L)N₃](H₂O)(ClO₄) (1) (L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,0^1.18, 0^7.12]docosane) has been prepared and characterized by X-ray crystallography. 1 crystallizes in the monoclinic space group P2₁/c, with a = 8.907(5), b = 20.036(3), c = 14.773(2) Å, = 103.78(2)°, V = 2560.6(15) ų, and Z = 4. The coordination geometry around the Cu(II) ion is a distorted square-pyramidal with four nitrogen atoms of the macrocycle and one nitrogen atom of the axial azido group.     

Synthesis and crystal structure of macrocyclic nickel(II) complex bridged by chromate

A novel compound catena-(-CrO₄-O,O)[Ni(L¹)Ni(L²)] 3H₂O (1) (L¹ = 3,5,10,12-tetramethyl-1,4,8,11-tetraazacyclotetradecane and L² = 2,5,9,12-tetramethyl-1,4,8,11-tetraazacyclotetradecane) has been synthesized for the first time and structurally characterized. 1 crystallizes in the triclinic space group P with a = 9.623(1), b = 10.084(1), c = 12.723 (3) Å, = 66.74(2), = 75.20(1), = 72.02(1)°, V = 1066.2(3) ų, and Z = 2. The coordination environment around the Ni(II) ions is an axially elongated octahedron with the secondary amines of the isomeric ligands and two oxygen atoms of [CrO₄]^2–.     

X-ray crystal structure of a macrocyclic tetraamine nitrito nickel(II) complex

The compound [Ni(L)(²-NO₂)]ClO₄ (L = 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane) has been synthesized and structurally characterized. It crystallizes in the monoclinic system, space group P2₁/c with a = 26.899(5), b = 8.476(2), c = 23.633(5) Å, = 115.12(13)°, V = 4878.6(17) ų, and Z = 4. Each nickel(II) ion has a six-coordinated bicapped square-pyramidal geometry with four secondary amines of the macrocycle and two oxygen atoms of the bidentate nitrito group. Electronic spectra and effective magnetic moment of the complex also exhibit a high-spin six-coordinated geometry.     

Crystal structure of a macrocyclic tetraamine isocyanato zinc(II) complex

The complex, [Zn(L)(NCO)]Cl · 3H₂O (1) (L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,0^1.18,0^7.12]docosane), has been synthesized and structurally characterized. 1 crystallizes in the monoclinic system, space group P2₁/n with a = 10.530(3), b = 9.315(2), c = 27.188(3) Å, = 92.58(1)°, V = 2664.1(9)ų, and Z = 4. The zinc atom is in a distorted squarepyramidal environment with the four nitrogen atoms of the macrocycle and one nitrogen atom of the isocyanate ligand.     

Structure and properties of cobalt(II) complex with a tetraaza macrocycle containing 2-pyridylmethyl pendant arms

The complex [Co(L)]Cl₂·10H²O (1) (L = 2,13,-bis(2-pyridylmethyl)-3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,0^1.18,0^7.12]docosane) has been synthesized and structurally characterized. Compound 1 crystallizes in the triclinic system, space group P-1 with a = 9.731(2) Å, b = 9.789(2) Å, c = 11.998(1) Å, = 66.66(1)°, = 76.95(1)°, = 87.99(2)°, V = 1020.4(3) ų, and Z = 1. The crystal structure of 1 shows that the complex is centrosymmetric and the cobalt(II) ion has a slightly distorted octahedral geometry with four nitrogen atoms of the macrocycle and two nitrogen atoms of the pendent arms at the axial positions. Cyclic voltammetry for 1 undergoes reversible one-electron oxidation to the Co(III) and irreversible one-electron reduction to the Co(I).     

A novel two-dimensional zinc(II) complex of a di-N-carboxymethylated tetraaza macrocycle linked by hydrogen-bonds

The complex [ZnL]·10H₂O (L = 2,13-bis(2-carboxymethyl)-3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,0^1.18,0^7.12]docosane) has been synthesized and structurally characterized. It crystallizes in the monoclinic system, space group P2₁/c with a = 10.159(1), b = 10.066(3), c = 17.268(2) Å, = 102.92(1)°, V = 1721.0(5) ų, and Z = 2. The crystal structure reveals an axially elongated octahedral geometry with bonds from the zinc(II) ion to the secondary and tertiary amines of the macrocycle and two oxygen atoms of the pendant carboxymethyl groups. The molecules of the zinc(II) complex are connected into a two-dimensional chain via hydrogen bonds.     

Synthesis and crystal structure of copper(II) complex with 1,9-diamino-5-methyl-5-nitro-3,7-diazanonane

Condensation of bis(ethanediamine)copper(II) perchlorate with formaldehyde and nitroethane in basic methanol was found to generate (1,9-diamino-5-methyl-5-nitro-3,7-diazanonane)copper(II) perchlorate, [Cu(L₁)](ClO₄)₂. The copper(II) complex was characterized by elemental analysis and infrared and electronic spectra studies. The structure of [Cu(L₁)](ClO₄)₂ was determined by X-ray diffraction. The crystal structure revealed that the copper ion is in an elongated octahedral coordination with four nitrogens at the equational position and perchlorate anions at the axial positions and that one of the perchlorate anions bridges two copper ions, leading to a linear polymeric structure in the crystal.     

Synthesis and crystal structure of tetraiminediphenolate diiron(II) macrocyclic complex

The crystal structure of the binuclear tetraiminediphenolate diiron(II) macrocyclic complex [Fe₂(tidf)(CH₃OH)₄](ClO₄)₂ (tidf = tetraiminediphenolate ligand) is presented. The molecular structure (monoclinic, space group C2/c, Z = 4, a = 20.6903(14)Å, b = 11.0827(11) Å, c = 16.0494(15) Å, = 99.911(6) shows two iron(II) cores occupying distorted octahedral geometries with four methanol molecules bound axially. Main equatorial bond distances are 2.050(3) Å for Fe—O1 and 2.067(4) Å for Fe—N1 with a Fe Fe distance of 3.108(1) Å. Contrasting to the monoiron complex the macrocycle does not adopt a bent conformation being nearly coplanar with the maximum deviation from the least-squares plane of 0.18 Å.     

Polymeric copper(II)-orotato complexes, [(C5H2N2O4)Cu(H2O)2]n

The compound [(C₅H₂N₂O₄)Cu(H₂O)₂]_n has been synthesized and its structure determined at room temperature. The primary coordination sphere at the Cu ion is square planar with the orotate dianion coordinating at the metal through heterocyclic nitrogen atom and adjacent oxygen of the carboxylate group, the remaining coordination sites are occupied by two water molecules. The orotate dianion is tricoordinated to one copper via N₁ and one oxygen of the carboxylato group and to another copper atom via the other oxygen of the carboxylato group. The coordination at copper is extended to five by the other oxygen of the carboxylate group of another orotate molecule. Thus, the molecules are associated to form chains, the carboxylato group acting as a bridge between the metal ions, the orotato-group being tridentate. The title compound crystallizes in the monoclinic space group. P2₁/n₁ with a = 9.515(5), b = 6.925(2), c = 11.861(6) Å, = 95.285(9)°, D _calc = 2.17 g cm^–3, and z = 4.     

Synthesis and structure of a hexaazamacrocyclic copper(II) complex with maleato ligand

A hexaazamacrocyclic copper(II) complex Cu(L)(H₂O) (O₂CCH = CHCO₂)⋅H₂O (1) (L = 3,10-bis(2-hydroxyethyl)-1,3,5,8,10,12-hexaazacyclotetradecane) was prepared and structurally characterized by a combination of analytical, spectroscopic, and crystallographic methods. In complex 1, the coordination geometry about the copper(II) ion is six-coordinate with four equatorial nitrogen atoms from the macrocycle and two oxygen atoms from the axial maleato and aqua ligands. In 1, the one end of the maleato ligand coordinates to the central copper atom, while the other end is not bonded. The macrocycle and the axial ligands are highly involved in multiple types of hydrogen bonding interactions, resulting in the stabilization of the maleato ligand as a “coordinated ligand counter anion.”     

Coordination complexes of 2,6-diarylpyrazines with copper(II) acetate

The coordination chemistry of a series of 2,6- and 2,3-diarylpyrazines with copper(II) acetate is reported. The 2:2 coordination complexes formed between two 2,6-diarylpyrazines and copper(II) acetate are characterized by X-ray crystallography. The structure (2,6-bis(3,5-dimethylphenyl)pyrazine)copper(II) acetate acetonitrile solvate, (C₄₈H₅₂Cu₂N₄O₈) (C₂H₃N) is triclinic, P 1, with a = 7.9685(10), b = 13.1893(16), c = 13.8267(17) Å, = 107.585(3)°, = 103.921(3)° and = 96.759(3)°. The structure of (2-(2,6-dimethylphenyl)-6-(3,5-dimethylphenyl)pyrazine)copper(II) acetate, C₄₈H₅₂Cu₂N₄O₈, is monoclinic, P2₁/c, with a = 8.2196(7), b = 12.5174(11), c = 21.7325(19) Å and = 96.201(2)°.     

Two novel two-dimensional frameworks with channels built from hydrogen bonds: Structures and properties study on copper(II) and nickle (II) complexes of the macrocyclic ligand 1,4,7-triazacyclodecane (tacd)

Two novel supramolecular complexes [Cu(tacd)₂](C₄H₃O₄)₂ (1) and [Ni(tacd)₂]Cl₂·4H₂O (2) were synthesized and their structures were characterized by elemental analysis, IR spectrum, TGA and single-crystal X-ray analysis. The results indicated that the complexes 1 and 2 assemble into different 2D supramolecular net-work structures with channels via hydrogen bonds interaction. TGA curves showed the steps of weight-loss for 1 and 2.     

(Imidazole)(3,3′-trimethylenedinitrilo bis (2-butanone oximate)) copper(II) perchlorate: Synthesis and crystal structure of a five-coordinate copper-protein model complex

The synthesis and crystal structure of the novel pentacoordinated complex [Cu(DOHPN)(IMI-DAZOLE)] (ClO4), (DOHPN=(3,3′-trimethylenedinitrilo bis 2-butanone oxime) are reported. The X-ray crystal structure (space groupP2₁/n, a=11.349(2) Å,b=14.241(3) Å,c= 12.635(3) Å; α=90°, β=100.21 (3)°, γ=90°) shows that the copper(II) ion occupies a distorted square-pyramidal geometry with the imidazole ligand occupying the axial position. The copper(II)-(N)imidazole distance is 2.125(3) Å and the copper(II)-tetraaza plane distance is 0.385/Å. The tetraaza ligand DOHPN adopts a “butterfly-like” geometry with a dihedral angle of 149.69°. The title complex is the first structurally characterized compound of the series [Cu(DOHPN)(axial ligand)]ⁿ⁺ where the axial ligand is a neutral N-heterocycle with known biological relevance. A comparison of the structural parameters with those observed when the axial ligand is H₂O or NCS^? (N-bonded) gives the following series with increasing metal-ligand interaction: H₂O>IMIDAZOLE>NCS^? (N-bonded).     

Crystal structure of a nickel(II) complex with macrocyclic tetraamine

A new compound [Ni(cyclen)(²-CH₃CO₂)]BF₄ (cyclen = 1,4,7,10-tetraazacyclodode- cane) has been synthesized and characterized structurally. It crystallizes in the orthorhombic system, space group Pnnm with a =12.045(5), b =14.906(6), c =8.913(4) Å, V =1600.4(12) ų, and Z =4. The nickel(II) ion has a distorted octahedral geometry with four secondary amines of the macrocycle and two oxygen atoms of the bidentate acetate group. TGA curve shows its thermal stability is up to 280°C.     

Synthesis and characterization of copper(II) hexaazamacrotetracyclic complex with thiocynate ligand

A mononuclear complex [Cu(L)(NCS)](ClO₄) (1) (L = 1,3,10,12,16,19-hexaazatetracyclo [17,3,1, 1^12.16,0^4.9]tetracosane) has been synthesized and structurally characterized by X-ray crystal structure analysis. The crystals are monoclinic P2₁2₁2₁ with a = 9.596(1), b = 11.285(1), c = 22.446(2) Å, V = 2430.7(3) ų, Z = 4. The copper atom is coordinated by two secondary and two tertiary amines of the macrocycle and one nitrogen atom of the thiocynate ligand in a distorted square-pyramidal geometry. The cyclic voltammogram of 1 exhibits two waves of a one-electron transfer corresponding to Cu^II/Cu^III and Cu^II/Cu^I processes.