Syntheses,Crystal Structures and Antibacterial Activities of Schiff Base of Nickel(Ⅱ) and Copper(Ⅱ) Complexes

A new kind of Schiff base HL(HL= 1-phenyl-3-methyl-4-(p-methylbenzoyl)-5-pyrazolone with L-Leucine methyl ester) and complexes Ni L′_2·0.75C_2H_5OH·0.25H_2O,Cu L′′2(L′ = 1-phenyl-3-methyl-4-(p-methylbenzoyl)-5-pyrazolone with L-leucine ethyl,L′′ = 1-phenyl-3-methyl-4-(p-methylbenzoyl)-5-pyrazolone with L-leucine) have been synthesized and structurally determined by X-ray diffraction. For HL: crystal structure determination indicates that there are two independent HLs with different conformations in one asymmetric unit. For complex 1: the Ni(Ⅱ) ion is six-coordinated by two carbonyl oxygen atoms from pyrazolone ring,two nitrogen atoms from different HL′ and two oxygen atoms from L-Leucine ethyl ester to form a distorted octahedral geometry. For complex 2: the Cu(Ⅱ) ion is four-coordinated by one carbonyl oxygen atom from the pyrazolone ring,one nitrogen atom from HL′′,and two different carboxylic oxygen atoms from L-leucine with the same conformation to form a distorted quadrilateral geometry.     

Synthesis and Characterization of Complexes of Copper(II), Nickel(II) and Cobalt(II) with vic-Dioximes Bearing N''-p-Aminobenzoyl Benzaldehyde Hydrazone

Six different arylhydrazone derivatives of p-aminobenzoic hydrazide of vic-dioximes were synthesized by reaction of chloroglyoxime and dichloroglyoxime with N＇-p-aminobenzoyl benzaldehyde, 4-hydroxybenzaldehyde and 4-methoxybenzaldehyde hydrazones, respectively. Metal-ligand （1 ： 2） complexes of vic-dioxime derivatives with Cu（Ⅱ）, Ni（Ⅱ） and Co（Ⅱ） were prepared from corresponding metal acetates. The ligands and their complexes were characterized on the basis of elemental analyses and spectral data. The complexing abilities of these new vic-dioximes toward transition metals of Co（Ⅱ）, Cu（Ⅱ）, Ni（Ⅱ）, Zn（Ⅱ）, Cd（Ⅱ）, Mn（Ⅱ） and Cr（Ⅲ） were determined by solid-liquid extraction studies.     

Studies on Transition Metal Complexes of Schiff Base( Ⅰ )——Oxygen-carrying Properties of Cobalt( Ⅱ )Schiff Base Complexes

Introduction The compounds that can take up and release molecular oxygen reversibly is of significance because they can be used as model compounds for the study of the reversible oxygenation mechanisms involved in the very complex natural oxygen carriers, e.g., the hemoglobins and hemocyanins, and as the means of separating molecular oxygen from the air. The dioxygen carriers extensively studied are the Cobalt     

Synthesis and Characterization of Aryl Acylguanidines and Their Copper(Ⅱ) Complexes

A series of eight N-mono-substituted aryl acylguanidines L~(1～8) were synthesized from the reactions of their parent acylthioureas and respective primary amines, including five R~1C(O)N=C(NHR~2)_2 with balanced arms(denoted as R~1–R~2–R~2: Ph–Ar'–Ar', L~1(1); Ph–Ar'–Ar', L~2(2); 1-Naph–Ar'–Ar', L~3(3); 1-Naph–Ar'–Ar', L~4(4); 2-Naph–Ar'–Ar', L`5(5); Ar' = 2,6-Me_2C_6H_3, Ar' = 2,6-iPr_2C_6H_3) and three R~1C(O)N=C(NHR~2)NHR~3 with unbalanced arms(denoted as R~1–R~2–R~3: Ph–Ar'–Ph, L~6(6); Ph–Ar' –Ph, L~7(7); Ph–Ar' –Ar', L~8(8)). Treatment of L~(1～5)(1～5) with copper acetate in a molar ratio of 2:1 in dichloromethane led to the formation of homoleptic Cu(Ⅱ) complexes trans-L_2~(n')Cu(9～13), in which the Cu(Ⅱ) center was stabilized by deprotonated ligands Ln'(n = 1～5) in the O,N-bidentate mode. When similar reactions of L~6(Ph–Ar'–Ph)(6) and L~7(Ph–Ar'–Ph)(7) that contain unbalanced arms were investigated, the Cu(Ⅱ) products trans-L_2~(6')Cu(14) and trans-L_2~(7')Cu(15) were formed by deprotonating the bulky amine groups in Ln(-NHAr' for L~6 and-NHAr' for L~7) rather than the-NHPh group. In sharp contrast, trans-L_2~(8')Cu(16) was obtained from two-arm unbalanced L~8(Ph–Ar'–Ar')(8) not by deprotonating the more bulky-NHAr' group but the relatively less bulky-NHAr' group. In a further exploration, the reaction of 1:1 mixed ligands Ln and Lm with copper acetate was found to give only homoleptic Cu(Ⅱ) complex L_2~(n')Cu instead of the heteroleptic one L~(n')CuL~(m'). The in vitro antibacterial activity of L~n was evaluated against S. aureus, E. coli and C. albicans by determining the minimum inhibitory concentrations(MICs) using Kirby-Bauer test.     

Synthesis, Characterization and Antimicrobial Activity of Potassium Hydro(benzoyl)(phthalyl)borate and Its Cobalt(II), Nickel(II), and Copper(II) Complexes

A new organoborate ligand, hydro(benzoyl)(phthalyl)borate has been synthesized as its potassium salt (KL) and treatment of KL with one equivalent of MCl2•6H2O gave complexes ML(H2O)x•Cl [x＝2, M＝Co(II), Ni(II); x＝1, M＝Cu(II)]. All compounds were characterized by elemental analysis, FTIR, 1H NMR, ESI MS, UV-Vis techniques, conductivity and magnetic data measurements. Spectroscopic results suggest a square planar geometry in the Cu(II) complex, while the Co(II) and Ni(II) complexes possess an octahedral geometry. Antibacterial activities (in vitro) of the ligand and its metal complexes were studied against two Gram positive (B. subtillis and B. magterium) and two Gram negative bacteria (E. Coli and S. boydi) at a single concentration (75 μg/mL) by using the Disc diffusion method. Antifungal activities (in vitro) were also checked for the compounds by using the same method against Candida albicans 10261, Penicillium sp. and Asperjillius niger., at a single concentration (50 μg/mL). The results showed that all the metal complexes, specially the nickel(II) complex, have higher antibacterial and antifungal activities than the corresponding potassium salt.     

Synthesis and Crystal Structure of Cobalt(Ⅱ) and Copper(Ⅱ) Complexes Involving L-Aamino Alcohols

Two novel L-amino alcohol coordination cobalt and copper complexes I and Ⅱ were obtained separately from the direct reaction of L-plenylglycinol with Co(Ⅱ) acetate tetrahydrate in anhydrous ethanol and L-leucinol with Cu(Ⅱ) chloride dihydrate in anhydrous methanol. The structures of I and Ⅱ were determined by single-crystal X-ray diffraction and further characterized by elemental analysis and IR. For I: [Co3(C51H66N3O16)]2(OAc), monoclinic, space group P21, a = 15.022(3), b = 14.242(3), c = 28.922(6) , β = 98.944(4)o, V = 6112(2) 3, Z = 4, Dc = 1.339 g/cm3, the final R = 0.0860 for 21906 observed reflections with I 2(I). For Ⅱ: Cu2[C24H58N4O7Cl]Cl, orthorhombic, space group P212121, a = 6.1861(13), b = 20.838(4), c = 28.274(6) , V = 3644.6(13) 3, Z = 4, Dc = 1.310 g/cm3, the final R = 0.0642 for 11106 observed reflections with I 2(I). The complexes were then used to catalyze the Henry reaction and catalytic activity determined by 1H NMR.     

Synthesis, Crystal Structure and Thermoanalysis of o-vanillin-ethylenediamine Schiff Base Copper( Ⅱ ) Complex

The crystal structure of the title compound [Cu (o-vanillin-ethylenediamine) (H2O)] is described. The complex crystallizes in the orthorhombic system, space group Pbn21 with formula = CuC18H20N2O5, cell dimensions are: a = 0.7490(3) nm, b = 0.9256(2) nm, c=2. 4691(6) nm, V=1.712 nm3, Z = 4, Dc=l.51 g/cm3. The kinetics of thermal decomposition of the complex was studied under the non-isothermal condition by TG. Kinetic parameters were obtained from the analysis of the TG, DTG curves by integral and differential methods. By comparison of the kinetic parameters, the most probable mechanism function is f(α) = (3/2) (1-α)[-ln(1-α)]1/3, and the mathematical expression for the kinetic compensation effect is lnA = 0. 201E+0. 531.     

Syntheses and Crystal Structures of Mono-and Binuclear Copper(Ⅱ) Mixed-ligand Complexes Involving Schiff Base

1 INTRODUCTION The chemistry of copper compounds has been extensively investigated and the relationship be- tween structure and reactivity, ranging from indus- trial catalysis to biochemistry activity, is of major importance. For binuclear copper(II) complexes equa- torially bridged by pair of hydroxide[1] or alkoxide[2, 3] groups, satisfactory linear correlation is found be- tween the Cu–O–Cu bridging angle and spin coupling between the metal centers. However, for binuclear copper(I…     

Synthesis and Characterization of 2,6-Bis(imino)phenoxy Cobalt Complexes

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Synthesis and Characterization of Two Binuclear Macrocyclic Zinc(Ⅱ) Complexes by Anion Exchange

Two macrocyclic zinc(II) complexes {[ZnL(VO3)2]·0.33H2O}n(1) and [ZnL(H2O)2][Ni(CN)4](2)(L = 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane) have been obtained from the reactions of [ZnL](ClO4)2 with NH4VO3 and K2[Ni(CN)4], respectively, and structurally characterized by elemental analysis, IR, XRPD, TG and X-ray diffraction. Single-crystal X-ray diffraction analyses indicated that the Zn(II) atom lies on an inversion center and is octahedrally coordinated by four nitrogen atoms of the tetradentate macrocyclic ligand in the equatorial plane and two oxygen atoms of [VO4] tetrahedra in the axial positions in 1, and two oxygen atoms of two water molecules in 2. Complex 1 shows a three-dimensional structure, which is constructed by the links of [VO3]nn- chains with [ZnL]2+, forming one-dimensional channels occupied by guest water molecules. The monomers of [ZnL(H2O)2]2+ and [Ni(CN)4]2- are connected through the intermolecular hydrogen bonds to form a two-dimensional sheet in complex 2.     

Synthesis and Crystal Structure of a New Three-dimensional Supramolecule of Copper(Ⅱ)Schiff Base Complex

A new three-dimensional supramolecule composed of copper-Schiff base complex,[Cu(naphdien)]Cl·H2O,where naphdien is Schiff base of 2-hydroxy-1-naphthaldehyde and diethyle-netriamine,has been synthesized and determined by single-crystal X-ray diffraction.It belongs to the monoclinic system,space group P21/c,with a=7.3490(15),b=7.0847(16),c=30.845(3)(A),β=95.33(3)°,V=1599.O(5)(A)3,Z=4,C15H20ClCuN3O2,Mr=373.33,Dc=1.551 g/cm3,μ=1.543mm-1,F(000)=772,R=0.0536 and wR=0.0927 for 2788 unique reflections with 1659 observed ones(I＞2σ(I)).In the crystal structure,mononuclear units[Cu(naphdien)]Cl·H2O are linked into a two-dimensional framework via strong hydrogen bonds,and extended into a three-dimensional supramolecular structure through π-π stacking interactions.     

Synthesis and Characterization of Nickel(Ⅱ) and Copper(Ⅱ) Complexes with Schiff Base (1R,2R)-(-)-Diaminocyclohexane-N,N'-bis(3-tert-butyl-5-(4'-benzoic acid)-salicylidene)

Two homochiral metallosalen complexes,Ni(salen) (salen=(1R,2R)-(-)-diaminocyclohexane-N,N'-bis(3-tert-butyl-5-(4'-benzoic acid)-salicylidene) 1 and Cu(salen) 2,have been synthesized and characterized by IR,microanalysis,TGA,powder and single-crystal X-ray crystallography. Both 1 and 2 crystallize in orthorhombic space group P2_12_12 with Z=4. For 1,α= 12.082(2),b = 15.447(3),c = 18.784(4)(A),V= 3505.7(12) (A)~3,M_r = 731.50,D_c = 1.386 g/cm~3,μ= 0.606 mm~(-1),F(000)=1544,the final GOOF=1.043,R=0.0496 and wR=0.1248 for 4791 observed reflections with Ⅰ> 2σ(Ⅰ). For 2,α=12.181(2),b=15.501(3),c=18.877(4)(A),V= 3564.3(12)(A)~3,M_r=736.33,Dc = 1.372 g/cm~3,μ=0.665 mm~(-1),F(000)=1548,the final GOOF= 1.062,R=0.0575 and wR=0.1508 for 4562 observed reflections with Ⅰ> 20(Ⅰ). The crystal structures of 1 and 2 are isostructural with very similar supramolecular structures. An infinite two-dimensional network is generated by hydrogen bonding interactions and intermolecular π…π interactions.     

Syntheses,Crystal Structures and Antibacterial Activities of Cobalt(Ⅱ) and Manganese(Ⅱ) Complexes with Schiff Base Ligand Derived from Tryptamine

Two new mononuclear complexes, namely [Co(L)_2](1) and [Mn(L)_2](2)(HL = N-(3-methylsalicylidene)tryptamine), have been synthesized by the reactions of the ligand with cobalt acetate or manganese acetate in anhydrous ethanol. The crystal structures of the complexes were characterized by IR spectrum, elemental analysis, PXRD and single-crystal X-ray diffraction analysis. Complex 1 crystallizes in monoclinic, space group C2/c, with a = 23.146(2), b = 9.4864(10), c = 13.9261(15) ?, β = 102.898(2)°, V = 2980.6(5) ?3, Z = 4, Dc = 1.367 g/cm3, F(000) = 1284 and μ = 0.616 mm-1. Complex 2 crystallizes in monoclinic, space group P21/n, with a = 14.807(11), b = 13.118(10), c = 16.663(13) ?, β = 111.237(14)°, V = 3017(4) ?3, Z = 4, Dc = 1.342 g/cm~3, F(000) = 1276 and μ = 0.477 mm-1. The units of complex 1 are linked by intermolecular N–H···π hydrogen bonds into infinite 1D chains, which are further extended into a 3D supramolecular structure by a series of π···π stacking interactions. The units of complex 2 are linked by intermolecular N–H···π hydrogen bonds and C–H···π hydrogen bonds into an infinite 3D supramolecular structure. Meanwhile, the antibacterial activities of the ligand and its complexes have been tested against four kinds of bacteria. The results show that the three compounds all have excellent antibacterial activities and that 1 and 2 possess stronger inhibiting effects against the bacteria than the Schiff base.     

Thin-Layer Chromatography of Some Monothio-β-Diketonate Complexes of Nickel,Zinc and Cobalt

Abstract

A silica gel adsorbent has been successfully used to separate three series of nickel, zinc and cobalt complexes of 1,1-difluoro-4-mercapto-4-(2′-thienyl)but-3-en-2-one, 1,1,1-trifluoro-4-mercapto-4-(2′-thienyl)but-3-en-2-one, 1,1,1-trifluoro-4-mercapto-2-(2′-naphthyl)but-3-en-2-one. For comparative purposes R_F data for the protonated ligands are also included. The ZnL₂ complexes gave R_F values in single and binary solvent systems which were similiar to the R_F values of the ligands; whereas, the NiL₂ and CoL₃ complexes gave R_F values which paralled each other in most solvents.     

Air-Stable Cobalt(II) and Nickel(II) Complexes with Schiff Base Ligand for Catalyzing Suzuki–Miyaura Cross-Coupling Reaction

The Co(II) complex [Co{C₆H₄–1,2-(N=CH–C₆H₄O)₂}] (I) and Ni(II) complex [Ni{C₆H₄–1,2-(N=CH–C₆H₄O)2}] (II) with Schiff base of o-phenylenediamine and salicylaldehyde have been synthesized. The structure of the ligand and its complexes were derived on the basis of various techniques such as elemental analysis, mass, FT-IR, electronic spectra and magnetic susceptibility. From the Singal crystal X-ray diffraction (SCXRD) analysis techniques (CIF file CCDC no. 1498772 (II)), it has been confirmed that the Schiff base ligand (L), coordinates to the metal ion in a tetradentate fashion through the nitrogen and oxygen atom. In addition, the square planar geometry of Ni(II) complex also has been confirmed from SCXRD. Electronic spectra, mass spectra, and magnetic susceptibility measurements reveal square planar geometry for the Co(II) complex. Synthesized complexes were used in cross-coupling of arylhalides with phenylboronic acid. The transformation offers products in good yields using 0.02 mmol catalysts loading, thereby proving the efficiency of the complexes as catalysts for Suzuki–Miyaura reaction.     

New Tetraazamacrocyclic Ligand with Neutral Pendent Groups 1,4,7,10-tetrakis (2-cyanoethyl)-l,4,7,10-tetraazacyclododecane (L) and Its Cobalt (Ⅱ), Nickel (Ⅱ) and Copper (Ⅱ) Complexes:Synthesis,Structural Characterization and Antitumor Activities

A new tetraazamacrocyclic ligand (L) with four neutral 2-cyanoethyl pendent groups and its divalent transition-metal complexes:[Co(L)(NO₃)]NO₃·H₂O (1),[Ni(L)(NO₃)]NO₃·3H₂O (2) and[Cu(L)(H₂O)](NO₃)₂ (3) have been synthesized. The crystal structures of (1) and (3) have been determined by X-ray analysis. In complex (1) the cobalt atom is coordinated by four nitrogen atoms and two oxygen atoms of a nitrate anion, which define a distorted octahedron. The other nitrate ion lies in the lattice as a counter ion.     

Synthesis and Color-tunable Fluorescence Properties of Schiff Base Zinc （II） Complexes Used as Electroluminescent Materials

Four kinds of bis(N-alkylsalicylaldiminato) zinc(ll) complexes were synthesized, and their molecular structures were determined by FT-IR and elemental analysis. Their photoluminescence properties were determined, which indicated that they could emit strong fluorescence varying from blue to yellow to reddish orange depending on their different molecular structures. They had good thermostability, solubility and film forming capability, and can be used as organic electroluminescent materials. These new complexes may afford the feasibility to realize full-color display with materials based on similar molecular structures.     

Thermodynamics of Copper(II), Zinc(II), Cobalt(II), Mercury(II), and Nickel(II) Complexation with α,α-Dipyrrolylmethene in DMF

Thermodynamics of complexation reactions between Zn(II), Ni(II), Hg(II), Co(II), and Cu(II) acetates and 3,35,5-tetramethyl-4,4-dibutyldipyrrolylmethene in DMF at 298.15 K is studied by calorimetric and spectrophotometric methods. The replacement of Zn²⁺, Ni²⁺, and Hg²⁺ ions by Co²⁺ and Cu²⁺ ions was found to increase the equilibrium constants of reactions of complex formation with dipyrrolylmethene by more than two orders of magnitude. The role of solvation interactions in coordination of dipyrrolylmethene by d-metal ions is established.