Novel Complexes of Zinc(II) with Different Proton Transfer Ion Pairs Obtained from Dipicolinic Acid: Synthesis, Characterization and X-ray Crystal Structure

Abstract  Three new complexes of zinc(II) with three different proton transfer compounds, obtained from pyridine-2,6-dicarboxylic acid (dipicolinic acid) and different Lewis bases, were synthesized and characterized using IR, ¹H NMR and ¹³C NMR spectroscopy and single crystal X-ray diffraction. The chemical formulae and space groups of the complexes are (pipzH₂)[Zn(pydc)₂] · 4H₂O, P2₁/n (1), (EDGnH₂)[Zn(pydc)₂] · 3H₂O, P2₁/c (2) and (pdaH₂)[Zn(pydc)₂] · 4H₂O, (3) where pydc, pipz, EDGn and pda are standing for dipicolinic acid, piperazine, ethylenediguanidine and 1,3-propanediamine respectively. Cell parameters of the complexes are a = 7.9493(4) ?, b = 13.4386(7) ?, c = 21.0557(11) ?, β = 90.415(5)° for 1; a = 9.785(3) ?, b = 25.671(4) ?, c = 9.3402(16) ?, β = 90.790(17)° for 2 and a = 8.411(5) ?, b = 11.650(7) ?, c = 12.793(8) ?, α = 115.534(9)°, β = 92.791(10)°, γ = 97.778(10)° for 3. The three crystal structures illustrate that the metal ion is six-coordinated by two pydc’s. In all three compounds a large number of O–H⋯O, N–H⋯O and C–H⋯O hydrogen bonds are observed. These interactions as well as other noncovalent interactions such as ion–pairing and π–π stacking play an important role in the formation and stabilization of supramolecular systems in the crystal lattices. Index Abstract  The main purpose of this paper is to report and discuss about the synthesis, characterization, crystal structure and non-covalent interactions of three supramolecular frameworks of six-coordinated Zn(II) complexes, obtained by the reaction of different proton transfer compounds, i.e. (pipzH₂)(pydc), (EDGnH₂) (pydc) · 3H₂O and (pdaH₂)(pydc) · (pydcH₂) · 2.5H₂O with corresponding metallic salts.      

Synthesis and Crystal Structure of a Novel Mixed Ligand Cadmium(II) Complex of Benz-1,3-Thiazoline-2-Thione and 1,10-Phenanthroline

Abstract  A novel cadmium complex [Cd(C₇H₄NS₂)₂(phen)] was synthesized by the reaction of a polymeric complex, [Cd(C₇H₄NS₂)₂] _n , with 1,10-phenanthroline (phen) as a ligand. The crystal structure was determined by single-crystal X-ray diffraction. The crystallographic data are: triclinic , a = 8.3670(6) ?, b = 10.9898(8) ?, c = 17.1404(13) ?, α = 95.567(2)o, β = 95.881(2)o, γ = 109.034(1)o, V = 1471.26(19) ?³ and Z = 2. The final R value is 0.0375 for 7154 reflections. The compound [Cd(C₇H₄NS₂)₂(phen)] is monomeric revealing a coordination sphere of N₄S₂ type. The Cd atom is surrounded by two thiazole N atoms, two exocyclic S atoms from two bidentate 1,3-benzothiazole-2-thiolate anions and two 1,10-phenanthroline N atoms. The Cd cation is six-coordinate with a distorted octahedral geometry. Graphical Abstract  The synthesis and crystal structure of a novel monomeric complex ‘[Cd(C₇H₄NS₂)₂(phen)]’ obtained by the reaction of polymeric complex, [Cd(C₇H₄NS₂)₂] _n , with 1,10-phenanthroline is reported.      

Synthesis,Characterization and Crystal Structure Determination of a Hepta-coordinated Cadmium(II) Complex with Thiocyanato-bridges

Abstract  A new cadmium(II) complex [(C₂₈H₂₄N₆)Cd(SCN)₂]₂(CH₃OH)₂ (1) has been synthesized and characterized by IR, UV spectra, TG-DTA technique and single crystal X-ray diffraction analysis. The crystallographic data for compound 1: triclinic P1ˉ, a = 9.630(2) Å, b = 11.123(3) Å, c = 15.396(4) Å, α = 106.93(1)°, β = 91.60(1)°, γ = 99.99(1)°, V = 1,548.5(6) Å³, Z = 1, Dc = 1.512 mg/m³, F(000) = 716, R ₁ = 0.0332, wR ₂ = 0.0907. The molecule contains a symmetrical dinuclear unit in which two Cd(II) ions are double bridged by two di-μ-1,3-SCN⁻ anoins with a cadmium–cadmium separation of 6.48 Å. Each Cd(II) ion is seven-coordinated with six nitrogen atoms and a sulfur atom to form a monocapped trigonal prism coordination geometry. In addition, the molecule is further connected by multiform intermolecular C–H···π, π···π interactions and hydrogen bonds to form a three-dimensional supramolecular structure. Graphical Abstract  A hepta-coordinated Cd(II) complex which exhibits a distorted a monocapped trigonal prism coordination geometry has been achieved by using bisbidentate Schiff-base ligand and thiocyanate anion.      

Synthesis, Crystal Structures and Properties of Two Copper (II) Complexes with Pyridazine Derivative Ligand

Abstract  Two new complexes, [Cu(L)₂(CH₃OH)] · (ClO₄)₂ (1) and [Cu(L)₂(H₂O)] · (NO₃)₂ (2), have been synthesized and their crystal structures have been determined by X-ray analysis, where L = 3-(3,5-bimethylpyrazole-yl)-6-chloro-pyridazine]. The complex 1 crystallizes in the monoclinic, space group C2/c, and the coordination configuration of copper (II) is better described as trigonal pyramidal geometry with four N atoms from L and one O_methanol^. The coordination configuration of 2 is quite similar to that of 1 except O_water instead of O_methanol^. The intermolecular hydrogen bonds link the repeat units and extend the molecules to multinuclear structures in both compounds. The spectral properties of the title compounds have been studied and discussed. Furthermore, the antibacterial activities of the title compounds have been detected, the results indicate that the ligands and two copper(II) complexes exhibit certain fungicidal activities again several bacteria. Index Abstract  Two new complexes, [Cu(L)2(CH3OH)]·(ClO4)2 (1) and [Cu(L)2(H2O)]·(NO3)2 (2), have been synthesized and their crystal structures have been determined by X-ray analysis, where L= 3-(3,5-bimethylpyrazole-yl)-6-chloro-pyridazine. The intermolecular hydrogen bonds extend the molecules to multinuclear structures in both compounds.      

Synthesis and Crystal Structure of a Mixed-Ligand Cobalt(II) Complex with 2-Aminobenzimidazole

Abstract  The cobalt(II) complex, [Co(abz)₂(SCN)₂] 1, has been synthesized by the reaction of cobalt(II) nitrate with ammonium thiocyanate and abz ligands (abz = 2-aminobenzimidazole), and was fully structurally characterized by elemental analysis, IR spectra, X-ray diffraction and thermogravimetric experiments. It crystallizes in the triclinic P-1 space group with a = 8.6316(10), b = 9.3426(10), c = 13.254(2) ?, α = 95.793(2), β = 95.870(2), γ = 115.7380(10), V = 945.1(2) ?³, and Z = 2. The central cobalt(II) atom is four-coordinated to nitrogen donors from two neutral abz ligands and two isothiocyanate anions respectively, adopting a slightly distorted tetrahedral geometry. In addition, the intermolecular N–H···N and N–H···S hydrogen bonds interactions link the discrete mononuclear units into infinite three-dimensional networks. Index Abstract  The essence sentence of the paper: In the mixed-ligand mononuclear complex, [Co(abz)₂(SCN)₂], the four coordinated cobalt(II) atom exhibits a slightly distort tetrahedron, which is further assembled into 3D infinite network by intermolecular hydrogen interactions.      

Synthesis and Crystal Structure of a Polymeric Cobalt(II) Complex with 1,2-bis(1,2,4-triazol-1-yl)ethane

Abstract The title complex [Co₂(bte)₃(NCS)₄(H₂O)₂] _n (bte = 1,2-bis(triazol-1-yl)ethane) has been prepared. Single-crystal X-ray analysis reveals that the complex crystallizes in space group P ī with a = 7.7962(2), b = 8.3407(4), c = 14.7735(5) ?, α = 86.835(2), β = 76.2031(9), γ = 80.583(3)°. The crystal consists of two discrete complexes, [Co(bte)(NCS)₂(H₂O)₂] and [Co(bte)₂(NCS)₂]. The structure of [Co(bte)(NCS)₂(H₂O)₂] consists of neutral chain containing Co(II) bridged by bte molecules. The six-co-ordination of Co²⁺ is achieved by means of two trans NCS⁻ ions and water molecules. The structure of [Co(bte)₂(NCS)₂] demonstrates a one-dimensional neutral chain through bte-bridge, in which the Co(II) atom is in a distorted octahedral environment formed by four nitrogen atoms of the triazoles and two nitrogen atoms from two trans thiocyanato liagnds. Index abstract Synthesis and Crystal Structure of a Polymeric Cobalt(II) Complex with 1,2-bis(1,2,4-triazol-1-yl)ethane This paper reports the synthesis and crystal structure of complex [Co₂(bte)₃(NCS)₄(H₂O)₂]_n (bte = 1,2-bis(triazol-1-yl)ethane), which consists two different neutral chains containing Co(II) bridged by bte molecules.      

Crystal Structures of (2-oxo-2H-Quinaxalin-1-yl)-acetic Acid and its Cobalt and Nickel Complexes and Their Comparison with (1,3-Dioxo-1,3-dihydro-isoindol-2-yl)-acetic Acid

Abstract The crystal structures of (2-oxo-2H-quinaxalin-1-yl)-acetic acid and its cobalt and nickel complexes are determined. The (2-oxo-2H-quinaxalin-1-yl)-acetic acid (1) crystallizes in orthorhombic, Pbca, a = 12.8571(11) ?, b = 9.4267(8) ?, c = 15.0095(13) ?, the cobalt complex of (2-oxo-2H-quinaxalin-1-yl)-acetic acid (2) crystallizes as dihydrate in triclinic, P-1 space group with a = 4.81150(10) ?, b = 11.8631(2) ?, c = 12.4867(3) ?, α = 71.7800(10)°, β = 79.2490(10)°, γ = 84.9020(10)° whereas the nickel complex of (2-oxo-2H-quinaxalin-1-yl)-acetic acid (3) crystallizes in monoclinic, P2₁/c space group with a = 14.9210(5) ?, b = 4.81730(10) ?, c = 15.7672(5) ?. and β = 99.823(2)°. The crystal structure of the ligand and the complexes are compared with structures of (1,3-dioxo-1,3-dihydro-isoindol-2-yl)-acetic acid and its cobalt and nickel complexes. Index Abstract The crystal structures of (2-oxo-2H-quinaxalin-1-yl)-acetic acid and its nickel and cobalt complexes are compared with (1,3-dioxo-1,3-dihydro-isoindol-2-yl)-acetic acid and its corresponding complexes with nickel(II) and cobalt(II).      

Synthesis and Crystal Structure of One-Dimensional Carboxylate-Bridged Copper(II) Complex with 2-Pyridylmethylamino-3-butyric acid

Abstract The tridentate Schiff base carboxylate-containing ligand 2-pyridylmethylamino-3-butyric acid (Hpaba) reacts with copper(II) perchlorate to give the one-dimensional chain complex {[Cu(μ-paba)](ClO₄)·H₂O} _n (1). The coordination geometry of each copper(II) ion is best described as a square-plane with two nitrogen atoms and one carboxylate oxygen atom of the ligand, and one carboxylate oxygen atom belong to another ligand. It crystallizes in the monoclinic system P2₁/c with a = 12.717(2), b = 7.9163(15), c = 14.981(2) ?, β = 111.14(1)°, V = 1406.8(4) ?³, Z = 4. Cyclic voltammogram of 1 undergoes the reversible one-electron oxidation to the Cu(III) and the reversible one-electron reduction to the Cu(I) state. Graphical Abstract Crystal structure of 1 reveals a syn-anti carboxylate-bridged one dimensional chain complex in which the coordination environment around each copper(II) ion exhibits a distorted square plane.      

Synthesis, Crystal Structure and DNA-Binding Study of a New Copper(II) Complex Containing Mixed-Ligand of Iminodiacetate Dianion and 6-Nitro-1H-benzimidazole

Abstract  A mixed-ligand complex Cu(IDA)(NBZIM)(H₂O) (IDA = iminodiacetate dianion, NBZIM = 6-nitro-1H-benzimidazole) has been synthesized and characterized by elementary analysis, IR, UV-Vis, molar conductivity and single crystal X-ray diffraction. It crystallizes in the triclinic system, space group P with a = 6.9423(14), b = 9.3100(19), c = 11.754(2) ?, α = 69.61(3), β = 85.87(3), γ = 83.87(3)°, Z = 2, R ₁ = 0.0463 and ωR ₂ = 0.0987. The single crystal X-ray analysis reveals that the Cu(II) atom is coordinated by one tridentate iminodiacetate dianion, one monodentate nitrobenzimidazole molecule and one water molecule, in a distorted square base pyramidal coordination geometry. The iminodiacetate dianion chelates the Cu(II) atom in the meridional mode. A three-dimensional network is formed by hydrogen bonds and stabilized by NBZIM π-π stacking interactions. The interaction of the complex with Fish sperm DNA has also been studied using absorption spectra. Index Abstract  In the crystal of Cu(IDA)(NBZIM)(H₂O), each molecule is linked to other six neighbouring ones by ‘eight’ hydrogen bonds in four cases by means of the ‘symmetry related’ linkage.      

Isolation and Crystal Structure of [Cu(L1)(O2CH)](ClO4)?·?H2O: Hydrolysis of DMF ( N , N -Dimethylformamide) by a Copper(II) Tetraazamacrocycle

The tetraazamacrocyclic copper(II) complex, [Cu(L)](ClO₄)₂ (L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo[14.4.0^1.18.0^7.12]docosane), hydrolyzes DMF at room temperature. The formate anion which is one of the hydrolyzed species of DMF coordinates to the copper(II) ion to form [Cu(L1)(O₂CH)](ClO₄) · H₂O (1). The crystals of the complex 1 were isolated and structurally characterized by a combination of analytical, spectroscopic, and crystallographic methods. In 1, the macrocyclic ligand contains two trans fused cyclohexane rings, and the coordination geometry about the copper(II) ion adopts a square pyramid with four equatorial nitrogen atoms from the macrocycle and an oxygen atom from the formato ligand with an uncoordinated perchlorate ion.     

Synthesis and Crystal Structure of Copper II and Silver I Complex with 1,4-diazabicyclo[2.2.2]octane[Cu(CBC)2(Dabco)(H2O)] n (1) and [Ag2(HBC)2(Dabco)] n (2)

Two 1D polymeric complex, [Cu(CBC)₂(Dabco)(H₂O)] _n (1) and [Ag₂(HBC)₂(Dabco)] _n (2) have been synthesized and characterized by X-ray single crystal analysis, where CBCH is p-chlorobenzoic acid, HBCH 2 is 2-hydroxybenzoic acid and Dabco is 1,4-diazabicyclo[2.2.2]octane. Complex 1 has been obtained in high yield by hydrothermal synthesis from CuO and CBCH and Dabco, and complex 2 has been obtain by evaporation of the solvent from silver salicylate and Dabco, 1 crystallizes in the orthorhombic space group Pmn2 ₁ with a = 24.3310(5) ?, b = 6.9050(6) ?, c = 5.9980(5) ?, Z = 2, V = 1007.70(4) ?³ and Dx = 1.657 g cm⁻³, 2 crystallizes in the monoclinic space group P2 ₁ /m with a = 10.292(3) ?, b = 6.913(2) ?, c = 14.417(4) ?, β = 95.660(5), Z = 2, V = 1020.8(5) ?³ and Dx = 1.959 g cm⁻³. The final R value is 0.0302 for 1323 measured reflections for 1 and the final R value is 0.0684 for 1545 measured reflections for 2. The atomic arrangement is built by infinite one-dimensional polymeric chain in both complexes. These chains are cross-linked by hydrogen bonds involving the coordinated water molecules to form a two-dimensional framework in complex 1.     

Synthesis and Crystal Structure of 2,13-Bis(acetamido)-3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,0<Superscript>1.18</Superscript>,0<Superscript>7.12</Superscript>]docosane Tetrachlorocobalt(II)dihydrate

Abstract The novel ionic compound [H₂bdtd][CoCl₄] · 2H₂O (1) was prepared by the reaction between CoCl₂ and 2,13-bis(acetamido)-3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,0^1.18,0^7.12]docosane (bdtd) in adjusted to pH 3.0 by 1.0 M HCl and structurally characterized. The crystals are monoclinic C2/c with a = 18.7777(9), b = 9.7356(4), c = 20.0884(9) ?, β = 109.6340(10)°, V = 3458.9(3) ?³, Z = 4. The dication H₂bdtd occupies a special position about an inversion center. The cobalt(II) atom in the anion is in a distorted tetrahedral environment with four chloride ligands. The crystal structure is stabilized by a variety of hydrogen-bonding contacts involving the dication, chloride anions and solvent water molecules. Cyclic voltammetry of [CoCl₄]²⁻ anion in 1 undergoes irreversible one-electron reduction to the Co^II/Co^I. Graphical abstract The crystal structure of the ionic compound [H₂bdtd][CoCl₄] · 2H₂O (1) consists of [H₂bdtd]²⁺ cation, [CoCl₄]²⁻ anion and water molecules joined together by ionic interaction and hydrogen bonds. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.