Crystal Structure and Characterization of [Ni(RPOEt)<Subscript>2</Subscript>(C<Subscript>2</Subscript>H<Subscript>5</Subscript>OH)<Subscript>2</Subscript>](ClO<Subscript>4</Subscript>)<Subscript>2</Subscript> [RPOEt = bis{(diphenylphosphinyl)methyl}ethyl phosphinate]

Abstract  

The compound [Ni(RPOEt)₂(C₂H₅OH)₂](ClO₄)₂ (1) [RPOEt = bis{(diphenylphosphinyl)methyl}ethyl phosphinate] has been prepared in the form of single crystals and characterized by elemental and thermal analyses, IR spectroscopy and by a single crystal X-ray diffraction study. The complex crystallizes in the triclinic P[`1] P\bar{1} space group with a = 9.8773(5), b = 13.741(1), c = 14.287(1) ?, α = 64.313(9), β = 70.280(5), γ = 89.973(7)o, V = 1620.5(2) ?³, and Z = 1. The nickel(II) atom in 1, situated at the centre of symmetry, is coordinated by four oxygen atoms from two RPOEt ligands and two oxygen atoms from two ethanol molecules in a slightly distorted octahedral environment. The third phosphoryl-oxygen atom from the phosphinate ligand is hydrogen bonded to the oxygen atom of the ethanol molecule coordinated to nickel(II). The complex [Ni(RPOEt)₂(C₂H₅OH)₂]²⁺ cations are linked by the C–H···O hydrogen bonds into one-dimensional chains and by the composite π···π and C–H···π phenyl interactions into a final three-dimensional structure.     

Crystal Structure of [Zn(2-Bromobenzoato)<Subscript>2</Subscript>]<Subscript><Emphasis Type="Italic">n</Emphasis></Subscript> and [Zn(2-Bromobenzoato)<Subscript>2</Subscript>(<Emphasis Type="Italic">N</Emphasis>-Methylnicotinamide)]<Subscript>2</Subscript>

Abstract  

The syntheses and structural characterizations of two novel 2-bromobenzoatozinc(II) complexes—[Zn(2-BrC₆H₄COO)₂] _n (I) and [Zn(2-BrC₆H₄COO)₂(mnad)]₂ (II), where mnad is N-methylnicotinamide are reported. Compound (I) crystallized with a monoclinic lattice (space group P2₁/c) and is polymeric in solid state. Its cell parameters are: a = 7.37220(10) Å, b = 19.9639(3) Å, c = 30.2756(5) Å, β = 94.7510(7)°, V = 4440.59(12) ų, Z = 4. The coordination environments of all zinc atoms are distorted tetrahedra built from four carboxylate oxygen atoms coming from four 2-bromobenzoato ligands. Compound (II) crystallized with a monoclinic lattice (space group P2₁/c) with a = 11.7488(2) Å, b = 20.3683(3) Å, c = 9.30130(10) Å, β = 100.3941(11)°, V = 2189.30(5) ų, Z = 2. This dimeric molecule features a paddle-wheel [Zn₂O₈] cage in solid state; the coordination environment of the central atom is square pyramidal consisting of four carboxylate oxygen atoms and the pyridine N atom of the mnad ligand.     

Two-Dimensional Hydrogen-Bonded Polymer from Nickel(II) Tetraaza Macrocyclic Complex and Succinate Ligand

Abstract  

The reaction of [Ni(L)]Cl₂·2H₂O (L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,0^1.18,0^7.12] docosane) with succinic acid (C₄H₆O₄) yields a 2D hydrogen-bonded polymer with formula [Ni(L)(C₄H₅O₄)₂] (1). This polymer complex has been characterized by X-ray crystallography, spectroscopy and cyclic voltammetry. The complex has a center of symmetry. The crystal structure of 1 exhibits a distorted octahedral geometry about Ni atom with four nitrogen atoms of the macrocycle and two oxygen atoms of the succinate ligand at the trans position. Compound 1 crystallizes in the monoclinic system C2/c with a = 14.8203(11), b = 12.3070(8), c = 17.4164(12) ?, β = 107.356(6)°, V = 3032.1(4) ?³, Z = 4. Electronic spectrum of 1 reveals a high-spin octahedral environment. Cyclic voltammetry of 1 undergoes two waves of a one-electron transfer corresponding to Ni^II/Ni^III and Ni^II/Ni^I processes.     

Crystal Structures of Two Aromatic Zinc(II) Carboxylates: [Zn(4-Chlorosalicylato)2(H2O)4]·2theophylline·(H2O)2 and Unique [Zn(5-Chlorosalicylato)2(isonicotinamide)2(H2O)]

Abstract  

The crystal structures of two zinc(II) 4-chloro- and 5-chlorosalicylate complexes, [Zn(4-ClC₆H₃-2-(OH)COO)₂(H₂O)₄]·2tph·(H₂O)₂ (I) and [Zn(5-ClC₆H₃-2-(OH)COO)₂(ina)₂(H₂O)] (II), where tph is theophylline and ina is isonicotinamide, have been determined using X-ray diffraction methods. Crystals of both (I) and (II) are triclinic, space group P-1, with Z = 1 in a cell with a = 7.2220(3), b = 8.59700(10), c = 16.0210(5) ?, α = 75.990(2), β = 83.959(2), γ = 68.455(2)°, V = 897.54(5) ?³ (I) and with Z = 2 in a cell with a = 11.4148(11), b = 11.5327(10), c = 12.0685(13) ?, α = 63.458(6), β = 87.547(8), γ = 89.387(7)°, V = 1419.9(2) ?³ (II). The coordination environment of the zinc(II) atom of compound (I) consists of two unidentate carboxylate oxygen atoms and four oxygen atoms of aqua ligands, forming a distorted octahedral configuration. Two theophylline molecules and the remaining water molecules are bound only by hydrogen bonds. The Zn atom of compound (II) is pentacoordinated with two unidentate carboxylate oxygen atoms, two pyridine nitrogen atoms of isonicotinamide ligands, and the oxygen atom of the aqua ligand, forming a distorted configuration between square pyramid and trigonal bipyramid. In both complexes intramolecular O–H···O hydrogen-bonding interactions are present. In the crystal structures, molecules are linked by intermolecular O–H···O and N–H···O hydrogen bonds. The structures are analyzed and compared to the similar Zn(II) complexes, with the chromophores ZnO₆ and ZnO₃N₂.     

Synthesis and Structural Characterization of a Nickel(II) Complex with Unsymmetrical NNO-Donor Schiff Base Ligand

Abstract  

The nickel(II) complex, Ni[C₅H₄N–CH=N–N=C(O)–C₆H₅]₂ (1) containing a N,N,O-donor hydrazone ligand, which is the 1:1 condensation product of benzhydrazide and pyridine-2-carboxaldehyde has been synthesized and characterized by single crystal X-ray diffraction technique, spectral study and room-temperature magnetic moments. Structural investigation shows that 1 crystallizes to a monoclinic system, having space group P2(1)/c, a = 11.221(4), b = 8.893(3), c = 23.026(8) ?, β = 90.605(14)°, and Z = 4. The central nickel atom is in an N₄O₂ coordination sphere developed with the NNO donor sets of the two independently hydrazone ligands. The Ni–N (pyridine), Ni–N (imine) and Ni–O (enolate) bond distances are 2.144(2) and 2.128(2); 1.980(2) and 1.985(2); 2.0782(17) and 2.1106(17) ?, respectively. The effective magnetic moment (μ _eff) value of 1 is found to be 3.10 B.M. at 300 K.     

Self-Assembly of One-Dimensional Coordination Polymer from Nickel(II) Macrocyclic Complex and Malonate Ligand

Abstract  

The reaction of [Ni(L)]Cl₂·2H₂O (L = 3.14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,0^1.18,0^7.12]docosane) with malonic (H₂mal) acid yields a one-dimensional coordination polymer [Ni(L)(mal)₂]_n (1). The structure was characterized by X-ray crystallography, spectroscopic and magnetic susceptibility. Each nickel(II) ion has a distorted octahedral coordination environment with the four secondary amines of the macrocycle in which two carboxylate anions of the malonate ligand have assembled around each nickel center. The compound crystallizes in the monoclinic system C2/c with a = 19.487(4), b = 8.4143(12), c = 14.6036(18) ?, β = 102.232(11)°, V = 2340.2(6) ?³, Z = 4. Electronic spectrum of 1 exhibits a high-spin octahedral environment. The magnetic behavior of 1 reveals a weak intramolecular antiferromagnetic interaction with J values of −1.91(1) cm⁻¹.     

Synthesis and crystal structure of the [WOCl<Subscript>3</Subscript>{<Emphasis Type="Italic">Ph</Emphasis>NHC(O)CHC(O-)<Emphasis Type="Italic">Me</Emphasis>}] complex

The [WOCl₃{PhNHC(O)CHC(O⁻)Me}] complex has been synthesized, and its crystal structure has been determined. The coordination polyhedron of the tungsten atom is a distorted octahedron with a meridional arrangement of three chlorine atoms. Two oxygen atoms of the acetoacetanilide bidentate chelating ligand occupy trans positions to the O(3) oxo atom and the Cl(3) atom. The crystal structures and the IR spectra of the WOCl₃{PhNHC(O)CHC(O^t-)Me} and [MoO₂Cl₂{(o-MePh)NHC(O)CH₂C(O)Me}] complexes are compared.     

Synthesis and Structural Characterization of <Emphasis Type="Italic">N</Emphasis>-(2-Pyridylmethyl)-3-Methoxysalicylaldiminato Copper(II) Chloride

Abstract  The copper(II) complex [Cu(C₅H₄NCH₂−N=CH–C₆H₃OCH₃–O)Cl], (1) containing a new tridentate Schiff base ligand (LH), which is the 1:1 condensation product of 2-(aminomethyl)pyridine and o-vaniline, has been synthesised and characterized by IR and UV–Vis spectra. Structural investigation shows that 1 crystallizes to a monoclinic system, having space group P2(1)/c, a = 6.9634(7), b = 18.1209(19), c = 10.3448(11) ?, α = 90°, β = 103.97(2)°, γ = 90° and Z = 4. The coordination geometry around the copper atom is slightly distorted square planar, formed by the N₂O donor set of the Schiff base and one Cl atom. The Cu–N(1), Cu–N(2), Cu–O(1) and Cu–Cl bond distances are 2.0114(14), 1.9414(14), 1.9147(12) and 2.2520(5) ?, respectively. Index Abstract  The copper(II) complex [Cu(C₅H₄NCH₂−N=CH–C₆H₃OCH₃–O)Cl], (1) containing a tridentate Schiff base ligand (LH), synthesised and characterized by IR and UV–Vis spectra. The central copper ion possesses a distorted square-planar geometry.      

Synthesis,Crystal Structure Properties of {μ-Nitrato-[<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>′-ethylene-bis(3-methoxysalicylideneimin) diaqua nitrato Cu(II)La(III)]nitrat}

Abstract  

The [μ-NO₃-LCuLa(NO₃)·(H₂O)₂]NO₃ (I) complex has been prepared and characterized by single crystal X-ray diffraction properties. The title compound crystallizes in the monoclinic system, space group P 2₁/c, with a = 9.1699(4), b = 21.6796(8), c = 13.7068(6) ?, α = γ = 90o, β = 111.308(3)°, V = 2538.63 (18) ?³ and Z = 4. The unit cell contains four discrete the title compounds. The central region is occupied by Cu^II and La^III ions which are brigged by two phenolato oxygen atoms of ligand. The intramolecular La–Cu distance is 3.5016 (3) Ǻ. The copper (II) ion is in a distorted square pyramidal geometry with the imino nitrogen atoms N1 and N2, and the phenolic oxygen atoms O2 and O3 forming the square base. The La^III ion is deca coordinated.     

The synthesis and crystal structures of new trinuclear and hexanuclear nickel complexes with metallodithiolate ligands

Two nickel complexes with metallodithiolate ligands, which can be regarded as the active site models of the acetyl coenzyme A synthase, were prepared and structurally characterized by X-ray crystallography. Reactions of Ni(PPh₃)₂Cl₂ with Ni(bme-dach) [bme-dach = N,N'-bis(mercaptoethyl)-1,4-diazacycloheptane] or Ni(bme-dach^*) [bme-dach^* = N,N'-bis(mercaptoethyl)-1,4-diazacyclohexane] in MeCN in the presence of NH₄PF₆ resulted in the formation of a trinuclear nickel complex {Ni[Ni(bme-dach)]₂}[PF_6-]₂ (1) and a hexanuclear nickel complex {Ni₂[Ni(bme-dach^*)]₄}[PF₆^?]₄ (2). The crystal structure of 1·2MeCN shows a square planar geometry of nickel atom that is coordinated by four sulfur atoms of the metallodithiolate ligands Ni(bme-dach). The crystal structure of 2·4MeCN reveals that each of the two nickel atoms is ligated by four sulfur atoms of the metallodithiolate ligands Ni(bme-dach^*) to form a square planar coordination sphere.     

Crystal Structure of Cuprate (II) Complex of Tetradentate ONNO Ligand: 4-[(2-{[(1<Emphasis Type="Italic">E</Emphasis>)-1-Methyl-3-oxobutylidene]amino}ethyl)imino]pentan-2-one

Abstract  

The title copper complex, Cu[CH₃CO–CH=C(CH₃)N(CH₂–CH₂)N(CH₃)C=CHCO CH₃], has been synthesized by the reaction of ligand, 4-[2-(1-methyl-3-oxo-but-1-enylamino)-ethylamino]-pent-3-en-2-one (ONNO) and copper chloride. The structure of the synthesized complex was determined by IR, NMR, mass spectroscopic data and X-ray crystallography. The structure was solved in monoclinic, space group P2₁/n with a = 10.971 (4), b = 8.988 (3), c = 12.830 (5) ?, β = 93.512 (5), V = 1,262.7 (6) ?³, Z = 4 and with R _int = 0.047. The geometry around the copper atom displays a distorted square-planner structure by coordinating with two oxygen atoms from carbonyl moiety and two nitrogen heteroatom from the central moiety of the ligands and thus established two 6-membered rings and one 5-membered ring. The two nitrogen atoms form two anionic–cationic bonds to complete the coordination sphere around the copper metal atom.     

Structural and Spectroscopic Study of Cu(II) Pyridine-2,6-dicarboxylate Complex with 2-Ethylimidazole

Abstract  

A mononuclear copper(II) complex, [Cu(pydca)(2-Etlm)(H₂O)] (1) (H₂pydca = pyridine-2,6-dicarboxylic acid, 2-Etlm = 2-ethylimidazole), has been synthesized and characterized by elemental analyses, IR, UV–Vis, TG-DTA and single crystal X-ray diffraction. The complex 1 is in the orthorhombic crystal system, space group Pbca and Z = 8. The structural analysis indicated that Cu(II) center is five coordinated in a slightly distorted square pyramidal geometry by one N and two O atoms from a 2,6-pyridine dicarboxylate dianion, one N atom from a 2-ethylimidazole ligand, and one O atom from a aqua molecule. This mononuclear motif of 1 is further assembled to 3D supramolecular framework through strong O–H···O and N–H···O hydrogen bonding interactions.     

Synthesis and Crystal Structure of One Trinuclear di-<Emphasis Type="Italic">n</Emphasis>-butyltin(IV) Complex with Salicylaldoxime

Abstract   One trinuclear di-n-butyltin(IV) complex with salicylaldoxime (o-HON=CHC₆H₄OH=HONZOH), (Bu₂Sn)(Bu₂SnO)(Bu₂SnOH)(ONZOH)(ONZO), has been synthesized and characterized by elemental analyses, IR spectrum, and single crystal X-ray diffraction. This complex is a small cluster displaying two unequivalent salicylaldoximate with one seven-coordinate pentagonal–bipyramidal tin atom linked two five-coordinate trigonal–bipyramidal tin atoms via a network of oxygen atoms by Sn–O–Sn bridges. The hydrogen bonds (o-HON=CHC₆H₄–O…H–O) are observed in the complex. These hydrogen bonds include intramolecular hydrogen bonds and intermolecular hydrogen bonds. (Bu₂Sn)(Bu₂SnO)(Bu₂SnOH)(ONZOH)(ONZO) belongs to monoclinic: space group P2₁/n, with a = 12.2307(15) ?, b = 17.361(2) ?, c = 20.976(3) ?, β = 94.424(2)°, V = 4440.5(10) ?³, Z = 4, D _c  = 1.500 g/cm³, μ(MoKα) = 1.715 mm⁻¹, F(000) = 2024, and final R ₁ = 0.0426, wR ₂ = 0.1064 for observed reflections 7779(I > 2σ(I)). Index abstract  The title compound, di-n-butyltin(IV) complex with salicylaldoxime, was synthesized and its crystal structure determined. Single crystal X-ray diffraction analysis reveals that the molecular structure of the title compound is trinuclear. The complex is a small cluster displaying two unequivalent salicylaldoximate with one seven-coordinate pentagonal–bipyramidal tin atom linked two five-coordinate trigonal–bipyramidal tin atoms via a network of oxygen atoms by Sn–O–Sn bridges.      

Synthesis and Crystal Structures of N′-3,5-Dibromo-2-Hydroxybenzylidene)-2-Hydroxy-3-Methylbenzohydrazide and its Oxovanadium(V) Complex [N′-(3,5-Dibromo-2-Oxidobenzylidene-κO)-2-Hydroxy-3-Methylbenzohydrazidato-κ2N′,O](Methanol-κO)(Methanolato-κO)Oxidovanadium(V)

Abstract  

A new hydrazine ligand N′-3,5-dibromo-2-hydroxybenzylidene)-2-hydroxy-3-methylbenzohydrazide (1) and its oxovanadium(V) complex [N′-(3,5-dibromo-2-oxidobenzylidene-κO)-2-hydroxy-3-methylbenzohydrazidato-κ ² N′,O](methanol-κO)(methanolato-κO)oxidovanadium(V) (2), were prepared and were structurally characterized by elemental analysis, IR spectra and single-crystal X-ray diffraction. Compound 1 crystallizes in the triclinic space group P−1, with unit cell dimensions a = 7.813(2) ?, b = 8.748(2), c = 26.071(6) ?, α = 85.763(2)°, β = 81.521(2)°, γ = 89.358(3)°, V = 1757.6(7) ?³, Z = 4, R ₁ = 0.0587, and wR ₂ = 0.1054. Compound 2 crystallizes in the triclinic space group P-1, with unit cell dimensions a = 7.777(3) ?, b = 11.594(3), c = 12.363(3) ?, α = 107.965(3)°, β = 103.190(2)°, γ = 96.656(2)°, V = 1011.3(5) ?³, Z = 2, R ₁ = 0.0634, and wR ₂ = 0.1480. The hydrazine ligand coordinates to the V atom through the phenolic O, imino N, and ethanolic O atoms. The V atom in the complex is in an octahedral coordination, with the three donor atoms of the hydrazine ligand and one methanolato O atom defining the equatorial plane, and with one methanol O and one oxo O atoms occupying the axial positions. The displacement of the V atom from the equatorial plane towards the axial oxo O atom is 0.305(2) ?.     

Synthesis and Crystal Structure of Phenolato-Bridged Dinuclear Copper(II) Complex with (2-Hydroxybenzyl)(2-pyridylmethyl)amine

Abstract  

The tridentate Schiff base phenol-containing ligand (2-hydroxybenzyl)(2-pyridylmethyl)amine (Hbpa) reacts with copper(II) perchlorate to give the phenolato-bridged dinuclear complex [Cu(bpa)(H₂O)]₂·2ClO₄ (1). Each copper(II) ion exhibits a distorted square-pyramidal environment, being coordinated by two nitrogen atoms and two phenolato oxygen atoms of the two deprotonated bpa ligands, and one oxygen atom of the water molecule. It crystallizes in the triclinic system P-1 with a = 7.8790(6), b = 8.9345(7), c = 12.0207(9) ?, α = 69.158(1), β = 85.307(1), γ = 76.629(1)°, V = 769.39(10) ?³, Z = 1. Cyclic voltammetry of 1 gives two oxidation and two reduced processes.     

A New Microporous Hydrogen-Bonding Framework Constructed from 1-(4-Hydroxyphenyl)-5-Thioacetatetetrazole

Abstract  

The new complex with flexible heterocyclic carboxylate ligand, [Ba(HL⁻)₂(H₂O)₃]·H₂O (H₂L = 1-(4-Hydroxyphenyl)-5-thioacetatetetrazole), were synthesized and structurally determined by X-ray diffraction analysis. The complex belongs to the monoclinic system, space group C2/c. The center Ba(II) is nine-coordinated by six carboxylate oxygen atoms from four HL-ligands and three water molecules in a distorted monocapped square trans-prism geometry. The ligand serves as a bridge to link two adjacent Ba(II) atoms into a chain structure which are further assembled into the final three-dimensional supramolecular architecture with microporous open channel via hydrogen bonds.     

Synthesis,Structural and Thermal Studies of a New Nickel Complex Containing 2-Aminopyrimidine and Thiocyanate Mixed Ligands with a Three-Dimensional Network Structure

Abstract  

A new nickel(II) complex formulated as, trans-[Ni(amp)₂(SCN)₂(H₂O)₂]·2H₂O (1), (amp = 2-aminopyrimidine) has been synthesized and characterized by elemental analysis, IR spectroscopy, its molecular and crystal structures were determined by X-ray crystal structure analysis and its thermal stability by TGA/DTA methods. 1 is a neutral complex and the central atom sits on an inversion center and is coordinated by two endocyclic nitrogen atoms of two 2-aminopyrimidine heterocycles, two oxygen atoms of two water molecules and two nitrogen atoms of SCN⁻ ions. 2-aminopyrimidine molecules, thiocyanate ions and water molecules are in trans position. Thermal methods confirm two co-crystallized water molecules in 1. π–π stacking interactions and extensive O–H···O, O–H···N, O–H···S and N–H···N hydrogen bonds contribute to the formation of a three-dimensional supramolecular structure. Crystal data for complex at 120 K: triclinic, space group P-1, a = 7.2026(14), b = 7.8332(15), c = 9.0270(17) ?, α = 67.694(3), β = 72.732(4), γ = 77.012(4), Z = 1, R ₁ = 0.0323.     

Synthesis and Crystal Structure of a Carboxylate Bridged Binuclear Copper Complex of Schiff Base Derived from β-amino acid and Salicylaldehyde

Abstract  

The tridentate ligand H₂L (H₂L = β-phenylalanine, N-[1-(2-hydroxyphenyl)propylidene] reacts with copper(II) nitrate and imidazole to give binuclear compound [Cu₂L₂(imi)₂] (1). The coordination geometry of each copper(II) ion is best described as a square-pyramided with one nitrogen atom, two oxygen atoms of the ligand one nitrogen atom of imidazole and one carboxylate oxygen atom belong to another ligand. It crystallizes in the monoclinic system P−1 with a = 7.8439(12) ?, b = 10.2717(16) ?, c = 11.6885(18) ?, α = 76.672(2)°, β = 85.397(2)°, γ = 71.412(2)°, V = 868.6(2) ?³, Z = 1.     

Synthesis,Structure and Magnetic Properties of a New Two-dimensional (4,4) Network Cobalt Coordination Polymer with Dicyanamide and Benzimidazole Ligands

Abstract  The new cobalt(II) coordination polymer [Co(bim)₂(dca)₂] _n (1), (bim = benzimidazole, dca = dicyanamide) was synthesized and characterized. X-ray diffraction analyses reveal that the title complex crystallizes in the monoclinic space group P2₁/n with a = 9.168(5), b = 9.959(5), c = 9.850(5) ?, β = 105.360(11)^o, Z = 2, and R ₁ = 0.0308, wR ₂ = 0.0728. The coordination geometry of cobalt atom is distorted octahedral, coordinated equatorially by four nitrogen atoms from four dicyanamide ligands, and axially by two nitrogen atoms from two benzimidazole molecules. Each dca ligand links two cobalt(II) atoms and 1 forms a two-dimensional (4,4) network. The spectroscopic and magnetic properties have also been investigated. Graphical Abstract  The new cobalt(II) coordination polymer [Co(bim)₂(dca)₂] _n (1), (bim = benzimidazole, dca = dicyanamide) was synthesized and characterized by X-ray diffraction analyses. The coordination geometry of cobalt atom is distorted octahedral, coordinated equatorially by four nitrogen atoms from four dicyanamide ligands, and axially by two nitrogen atoms from two benzoimidazole molecules. Each dca ligand links two cobalt(II) atoms and 1 forms a two-dimensional (4,4) network. The spectroscopic and magnetic properties have also been investigated.      

Metal Ion Interactions with Pyridinecarboxylates in Tripodal tris(2-Aminoethyl)amine Ligand System: Crystal Structures of [Ni(tren)(pic)]2(ClO4)2·CH3OH and [Co(tren)(dipic)]ClO4·CH3OH

Abstract  

Two new complexes [Ni(tren)(pic)]₂(ClO₄)₂·CH₃OH (1) and [Co(tren)(dipic)]ClO₄·CH₃OH (2), (tren is tris(2-aminoethyl)amine, pic is the anion of picolinic acid, dipic is the dianion of 2,6-pyridinedicarboxylic acid) have been synthesized and structurally characterized. X-ray analysis indicates that the two complexes are mononuclear with tren acting as a quadridentate ligand. In complex 1, the nickel(II) ion is further coordinated with picolinate in μ₂-N, O bidentate chelating mode. In complex 2, the cobalt(III) ion is coordinated with the pyridine nitrogen and one carboxylic oxygen of 2,6-pyridinedicarboxylate in μ₂-N, O chelating form. The metal atoms in both cases have distorted octahedral geometry. Crystal data: [Ni(tren)(pic)]₂(ClO₄)₂·CH₃OH (1), Mr = 869.03, monoclinic, C2/c, a = 26.354(5) ?, b = 10.407(2) ?, c = 25.839(5) ?, β = 96.24(3)°, Z = 8, V = 7045(2) ?³, R ₁ = 0.0418, wR ₂ = 0.1063 [I > 2σ(I)]; [Co(tren)(dipic)]ClO₄·CH₃OH (2), Mr = 501.77, Triclinic, P-1, a = 8.3667(2) ?, b = 10.4434(2) ?, c = 11.9431(16) ?, α = 73.9590(10)°, β = 88.0240(10)°, γ = 75.5890°, Z = 2, V = 969.97(4) ?³, R ₁ = 0.0408, wR ₂ = 0.1063 [I > 2σ(I)].