Synthesis and Structural Characterization of Two Tetra-Coordinated Co(II) Complexes with Benzimidazole Derivatives

Crystallography Reports - Two mononuclear tetra-coordinated cobalt(II) complexes with molecular formula [Co(L)2(SCN)2] (L = 1-methylbenzimidazole (mbim), 1; L = 1-methyl-2-aminobenzimidazole...     

Two Co/Ni(II)-Based Coordination Polymers for Degradation of Dyes

Crystallography Reports - Two isostructural Co/Ni(II)-based coordination polymers, namely, {[Co1/2(bpba)(H2O)]?2H2O}n (1) and {[Ni1/2(bpba)(H2O)]?2H2O}n (2), where Hbpba = 3,5-bis...     

Synthesis,Crystal Structure and Physicochemical Characterization of Two Ni(II)-Famotidine Metal Complexes

The coordination ability of the antisecretor agent Famotidine (FMT) was explored using Ni(II) as central ion. [NiFMT_H-2] and [Ni(FMT)₂]Cl₂ were obtained by the solvent evaporation method from the corresponding starting solutions at pH 8 and 4, respectively; the crystal structure was elucidated by single crystal X-ray diffraction in both cases.[NiFMT_H-2] resulted in a distorted square-planar geometry, where FMT acts as a tetradentate dianionic ligand through nitrogen atoms belonging to the guanidine group, the thiazolic ring and the side chain, and a sulfur atom from the thioether moiety. [Ni(FMT)₂]Cl₂ exhibits an octahedral environment composed by two FMT molecules that coordinate by nitrogen atoms deriving from guanidine and thiazole ring moieties, and the thioether sulfur atom. The physicochemical characterization was completed by means of FTIR and UV–Vis spectroscopies, and thermal analysis. Solubility measurements were performed and the results could be satisfactorily correlated with the solvation Gibbs free energy (ΔG_solv) values in aqueous solution obtained using the SDM model by DFT calculations.

Graphic Abstract

Ni(II) and famotidine form an octahedral complex at pH 4 where famotidine acts as a tridentate neutral ligand. In basic medium, it behaves as a tetradentate dianion, resulting in a quasi-planar complex. Spectroscopic and thermal data are consistent with single crystal X-ray diffraction structural elucidation. The relative stabilities were assessed by theoretical studies.

     

两个晶态异质同构配合物荧光材料的合成、结构及性质

在水中采用蒸发溶剂的方法,合成了两个异质同构的单核配合物[M(phen)2(H2O)2]·2SIPH2·2H2O (M=Zn,Co),SIPH2=间苯二甲酸-5-磺酸根阴离子,phen=1,10-邻菲罗啉).在两个配合物结构单元中,中心离子与两个1,10-邻菲罗啉和两个水分子配位,形成[M(phen)2(H2O)2]2+阳离子.两个未配位的水分子与[M(phen)2(H2O)2]2+阳离子,SIPH2-阴离子通过氢键相互连接形成三维的网状结构.SIPH2-阴离子起到平衡电荷的作用.室温下两个配合物均具有荧光发射峰,其发射峰分别在460 nm和439 nm.与配体相比,均发生明显的红移.荧光寿命分别为1.7638 ms和1.6356 ms.     

Synthesis and Crystal Structure Determination of Dimeric Co(II) and Ni(II) with Pyridine 2,6-Dicarboxylic Acid

Abstract  

Two new dimeric complexes of Ni and Co with pyridine 2,6-dicarboxylic acid were synthesized, the structure of both these complexes were determined by single crystal X-ray crystallography and was characterized spectrally with the help of IR and UV spectrometers and the magnetic moments of both the reported complexes were recorded. Both of these complexes crystallize in the monoclinic space group P 2₁/c1. For the dimeric cobalt complex, formula C₁₄ H₂₁ Co₂ N₂ O₁₅; a = 8.3950(3) ?; α = 90°, b = 27.3702(8) ?; β = 98.211(2)°, c = 9.6235(3) ?; γ = 90° and Z = 3. For the dimeric Nickel complex, formula C₁₄ H₂₁ Ni₂ N₂ O₁₅, a = 8.330(10) A; α = 90°, b = 27.266(5) A; β = 98.61(10)^o, c = 9.653(10) A; γ = 90° and Z = 4. Both the dimeric complexes were observed to be hexa-coordinated with two different types of donor atoms (nitrogen and oxygen). Details of the synthesis, structures and spectroscopic properties have been discussed.     

Crystal Structure and Photoluminescent Properties of Two Cadmium(II) Complexes with Orotic Acid

Abstract  

Assembly of orotic acid (2,6-dioxo-1,2,3,6-tetrahydropyrimidine-4-carboxylic acid, H₃dtpc) and Cd(OAc)₂·2H₂O gave rise to two complexes [Cd₂(H₂dtpc)₂(H₂O)₆] (I) and [Cd(H₂dtpc)(bpy)(H₂O)]_n (II) (bpy = 2,2′-bipyridine). Complex (I) and (II) have been characterized by X-ray single crystal diffraction, IR, PXRD, TGA and fluorescence spectra. Structural analyses reveal that (I) is a binuclear structure, and complex (II) possesses a one-dimensional infinite zig-zag chain architecture and the chains are further assembled into 2D supramolecular network by strong hydrogen bonding interactions. Crystal data for (I): Monoclinic, space group P2(1)/n, a = 9.3221(19) ?, b = 6.6315(13) ?, c = 15.322(3) ?, β = 102.31(3)°, V = 925.4(3) ?³, Z = 4, R1 = 0.0269, and wR2 = 0.0604; for (II): Monoclinic, space group P2(1)/c, a = 9.9880(2) ?, b = 14.5085(2) ?, c = 11.6957(2) ?, β = 107.976(2)°, V = 1612.10(5) ?³, Z = 4, R1 = 0.0234 and wR2 = 0.0554.     

Crystal Structure and Thermal Decomposition of Square Planar Ni (II) Complexes with ONS Type Ligands

Abstract  

Similar square planar complexes in the literature were prepared with ONS type N-(2-mercaptophenyl) salicylaldimine and Ni (II). The fourth coordination alongside the tridentate organic ligand was provided by the amine group. The complexes prepared were characterized with Elemental Analyses, IR Spectroscopy and Thermal Analyses. The molecular structures both of the complexes were also determined with X-ray diffraction. The Ni (II) complex was observed to have a highly distorted square planar structure. The temperature range where the nitrogen containing tridentates ligand left the structure and the corresponding heat changes were compared with those in the literature. The residue after thermal decomposition above 650 °C was found to be NiO.     

Crystal Structure of Three Isomorphous Compounds of 2,5-Dibromopyridine with Tetrahalometalate(II) Ions

Abstract  Three salts of 2,5-dibromopyridinium with metal halides, (C₅H₄Br₂N)₂[CuCl₄], (I); (C₅H₄Br₂N)₂[CuBr₄], (II); and (C₅H₄Br₂N)₂[CdBr₄], (III), are isomorphous in C2/c with cell volumes 1864.5(8), 1974.6(4) and 2072.9(7) ?³, respectively. For the Cu cases (I) and (II) the discrete [MX₄]²⁻ anions are strongly distorted with max/min tetrahedral angles of 131.19(8)°/99.67(9)° and 130.24(5)°/99.36(11)°, respectively. For the Cd case (III) the distortion is much less with max/min tetrahedral angles of 115.97(3)°/105.99(4)°. The cations are planar. The short hal···hal contacts are for (I), aryl Br···anionic Cl 3.335(3) ? and 3.430(2) ?; for (II), aryl Br···anionic Br 3.473(2) ? and 3.567(2) ?; and for (III), aryl Br···anionic Br 3.452(1) ? and 3.675(1) ?. Longer aryl Br···aryl Br contacts (3.842(2) ? to 3.967(2) ? are present in the three isomorphs. Bifurcated hydrogen bonding to two anionic halides exist in the three structures with N–H···Cl 3.365(8) ? and 3.379(7) ? in (I), N–H···Br 3.539(11) ? and 3.425(11) ? in (II), and N–H···Br 3.426(5) ? and 3.387(5) ? in (III). Short ring contacts exist with the perpendicular distances between mean cation planes in (I), (II), and (III) of 3.68(6) ?, 3.56(1) ? and 3.72(1) ?, respectively. Index Abstract  An analysis is made of the competition between hydrogen bonding, halogen–halogen and halogen–halide interactions as well as differences between [CuX₄]²⁻ and [CdX_4] ²⁻ polydedra in the structures of the three isomorphs.      

Complexes with Hg(II) and macrocyclic ligands

The crystal structures of 1,4,7,10,13,16-hexaoxa-cyclooctadecane dicyano mercury(II) monohydrate, C₁₄H₂₄HgN₂O₆·H₂O, 1, and 2,5,8,11,18,21,24,27-octaoxa-tricyclo[26.4.0.0_12,17]-dotriconta-1(28),12,14,16,29,31-hexaene dicyano mercury(II) monohydrate, C₂₆H₃₂HgN₂O₈·H₂O, 2, were determined: 1 crystallizes in the trigonal space group R3¯ with cell dimensions a = 11.7842(1) and c = 12.0316(1) Å. 2 crystallizes in the monoclinic space group P2₁/c with cell dimensions a = 11.156(3) Å, b = 8.417(2), c = 30.901(8) Å, and = 93.279°. In spite of the different cyclic systems, similar complexes are formed where the Hg atom is coordinated by two CN groups and six oxygen atoms of the crown ether. The structure of 1 is isostructural with the crystal structures of 18C6—HgCl₂, 18C6—CdBr₂, 18C6—Sr(BH₄)₂, and 18C6—Ba(BH₄)₂. Furthermore, 1 is very similar to other 18C6—HgX₂ complexes.     

Synthesis,Crystal Structures and Fluorescence Properties of Ni (II) and Cu (II) Complexes with 1-(Furan-2-ylmethylene)-4-phenylthiosemicarbazone

Abstract  

Two coordination complexes, NiL ₂ and CuL ₂ {L = bis[1-(furan-2-ylmethylene)-4-phenylthiosemicarbazone]}, were synthesized and determined by X-ray crystallography. Both crystallize in the Orthorhombic system, space group Pbcn, with lattice parameters: a = 11.935 (2) Å, b = 15.314(3) Å, c = 12.952(3) Å and Z = 4 for Ni (II); a = 20.850(4) Å, b = 15.049(3) Å, c = 7.5633(5) Å and Z = 4 for Cu (II). In both complexes, the central metal atom is coordinated in a distorted square-planar with two ligands through two S and N atoms, respectively. The EA, UV, IR and TG-DTG were studied and the possible structures of the complexes were speculated. Moreover, the fluorescence of the complexes were studied. The results reveal that copper complex can emit purple fluorescence in solvents.     

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.      

Growth kinetics of ammonium oxalate monohydrate single crystals from aqueous solutions containing Co(II) and Ni(II) impurities

The growth kinetics of different faces of ammonium oxalate monohydrate (AO) single crystals from aqueous solutions containing different concentrations of Co(II) and Ni(II) ions at a constant temperature are described and discussed. It was found that: (1) at a given supersaturation σ, both Co(II) and Ni(II) ions lead to a decrease in the growth rates R of different faces of AO crystals, (2) the growth of a particular face of the crystals occurs above a critical supersaturation σ_d, but there is also another supersaturation barrier σ* when the rate abruptly increases with σ, and (3) the values of σ_d and σ* increase with increasing concentration c_i of the impurity. The experimental R(σ) data for different concentrations c_i of the impurities were analysed according to the model involving complex source of cooperating screw dislocations and concepts of instantaneous and time‐dependent impurity adsorption. Analysis of the data showed that: (1) adsorption of Co(II) and Ni(II) impurities occurs on the surface terrace of AO crystals, (2) there is a simple relationship between Langmuir constant K and the impurity concentration c_i* corresponding to maximum surface coverage, and (3) the ratio σ_d/σ* of the supersaturation barriers observed in the presence of both impurities increases with an increase in impurity concentration c_i, and may be explained from the standpoint of the mechanism of adsorption of impurity particles at kinks and ledges. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Two Novel Crystal Structures of 2-Mercapto-1,3,4-thiadiazole Complexes with Mercury (II) Chloride

Abstract  

Two novel complexes 1 and 2 have been simultaneously obtained by the reaction of 2-mercapto-1,3,4-thiadiazole (MTD) with mercury (II) chloride (HgCl₂) in CH₃CN, and their crystal structures are characterized by single-crystal X-ray diffraction analysis. Crystal structures show that each Hg(II) of 1 is four coordinated with two chloride anions and two exocyclic sulfur atoms of two adjacent MTDs, and each Hg(II) of 2 is three coordinated with one chloride anion, one nitrogen atom and one exocyclic sulfur atom of two adjacent MTDs, respectively. Assisting the intermolecular works such as S···S, S···Cl or Hg···S interactions, both two complexes 1 and 2 are formed 2D supramolecular architectures. The results obtained conform the MTD can exist thiol and thione forms in the solid state.     

Two Complexes from One Reaction of Nickel(II) Ion with a New Schiff Base Ligand

Abstract  

A new Schiff base ligand of 1-(2, 6-dichlorobenzylidene)-4-phenylthiosemicarbazide(C₁₄H₁₁Cl₂N₃S) has been synthesized, which crystallizes in monoclinic, space group C2/c with a = 18.551(7) ?, b = 6.963(3) ?, c = 23.185(9) ? and β = 93.122(6)o. The reaction of this ligand with NiAc₂·4H₂O gives two different Ni(II) complexes, one is general traditional mononuclear and another is unexpected trinuclear, where another quadridentate ligand of 1-(amino-N-phenylmethanethio)-4-phenyl-thiosemicarbazide(C₁₄H₁₄N₄S₂) is found. The mononuclear complex (C₃₂H₂₆Cl₄N₈NiS₂) crystallizes in triclinic, space group P−1 with a = 11.071(2) ?, b = 11.157(2) ?, c = 15.302(3) ?, α = 76.214(2)o, β = 87.902(2)o and γ = 79.586(3)o. The trinuclear complex (C₆₀H₅₀Cl₄N₁₆Ni₃S₆) crystallizes in orthorhombic, space group Pbcn with a = 19.673(3) ?, b = 16.094(3) ? and c = 20.465(4) ?. In above three compounds, there are some hydrogen bonds which help to construct the three dimensional net works and stabilize the molecular structures.     

Synthesis and Crystal Structures of pH-Dependent Ni(II) Coordination Polymers with 3-Pyrid-3-ylbenzoic Acid

Abstract  

Two pyridinecarboxylato-bridged coordination polymers[Ni(pbc)₂(H₂O)₂]_n(1) and {[Ni(pbc) ₂ (H₂O)]·H₂O}_n (2)(Hpbc = 3-Pyrid-3-ylbenzoic acid) have been synthesized by the hydrothermal method and characterized by elemental analysis, IR spectrum and single crystal X-ray diffraction. Compound 1 crystallizes in monoclinic, space group P2₁/c with a = 9.519(5) ?, b = 9.417(5) ?, c = 11.701?, β = 98.086(5)°, V = 1038.5(9) ?³, Z = 2. Compound 2 crystallizes in monoclinic, space group P2₁/c with a = 10.490(2) ?, b = 12.920(3) ?, c = 16.074?, β = 95.97(3)°, V = 2166.7(8) ?³, Z = 4. X-ray diffraction analysis reveals that all pbc⁻ ligands act as diconnectors to link two Ni(II) centers and adopt one coordination mode: μ₂−N, O in compound 1 and the ligands adopt two coordination modes: μ ₂ −N, O and μ ₃ − N, O, O in compound 2.