Synthesis,crystal structures,and antimicrobial activity of a pair of isostructural dinuclear copper(II) complexes derived from 4-nitro-2-[(2-diethylaminoethylimino)methyl]phenol

A pair of isostructural azido- or thiocyanato-bridged centrosymmetric dinuclear copper(II) complexes, [Cu₂L₂(μ_1,3-N₃)₂] (1) and [Cu₂L₂(μ_1,3-NCS)₂] (2), derived from the Schiff base ligand 4-nitro-2-[(2-diethylaminoethylimino)methyl]phenol (HL), have been synthesized and characterized by elemental analysis, IR spectra and single crystal X-ray diffraction. Each Cu atom in the complexes is five-coordinate in a square pyramidal geometry by one O and two N atoms of one Schiff base ligand, and by two terminal donor atoms from two bridging azide or thiocyanate ligands. Both the azide and thiocyanate ligands adopt end-to-end bridging mode in the complexes. The distance between the two copper atoms is 5.205(2) Å for (1) and 5.515(2) Å for (2). The antimicrobial activity of the complexes has been tested.     

Syntheses and crystal structures of two copper(II) complexes derived from 2-bromo-4-chloro-6-[(2-morpholin-4-ylethylimino)methyl]phenol

Two new copper(II) complexes, [CuL₂] (1) and [Cu₂L₂(NCS)₂] · 2CH₃CN (2) (HL = 2-bromo-4-chloro-6-[(2-morpholin-4-ylethylimino)methyl]phenol), have been synthesized and characterized by elemental analyses, infrared spectroscopy, and single-crystal X-ray diffraction. Complex 1 was synthesized by reaction of HL with copper(II) acetate in methanol, while 2 was synthesized by adding ammonium thiocyanate to a methanol/acetonitrile (V : V = 2 : 1) solution of 1. Complex 1 crystallizes in the P2₁/n space group, and the thiocyanato-bridged dinuclear copper(II) complex, 2, crystallizes in the Pbcn space group. The Cu in 1 is four-coordinate square-planar with two imine N and two phenolate O atoms from two Schiff-base ligands. The Cu in 2 is five-coordinate square-pyramidal with NNO donor atoms of one Schiff-base ligand and one N atom of a bridging thiocyanate ligand defining the basal plane, and with one S atom of another bridging thiocyanate ligand occupying the apical position.     

Synthesis,crystal structures,and antimicrobial activity of copper(II) and zinc(II) complexes derived from 2-bromo-4-chloro-6-[(2-morpholin-4-ylethylimino)methyl]phenol

An end-to-end azido-bridged dinuclear copper(II) complex [Cu₂L₂(μ_1,3-N₃)](NO₃) (I) and a mononuclear zinc(II) complex [ZnCl₂(HL)] ? CH₃OH (II), where L is 2-brom-4-chloro-6-[(2-morpholin- 4-ylethylimino)methyl]phenolate, have been prepared and characterized by elemental analyses, IR, and single crystal X-ray crystallographic determination (CIF files CCDC nos. 1415217 (I), 1415218 for (II)). The crystal of I is monoclinic: space group C2/c, a = 28.684(2), b = 7.1787(5), c = 18.292(1) Å, β = 117.887(3)°, V = 3329.1(4) ų, Z = 4. The crystal of II is monoclinic: space group P2₁/c, a = 10.8207(9), b = 12.3398(7), c = 14.9477(7) Å, β = 93.473(3)°, V = 1992.2(2) ų, Z = 4. The Schiff base ligand in I coordinates to the Cu atom through the phenolate O, imine N, and morpholine N atoms, while the Schiff base ligand in II coordinates to the Zn atom through the phenolate O and imine N atoms, with the morpholine N atom protonated. The effect of these complexes on the antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans was studied.     

Zinc(II) and nickel(II) complexes derived from 2-bromo-6-[(2-Isopropylaminoethylimino)methyl]phenol: Synthesis,structures, and antimicrobial activity

The Schiff base 2-bromo-6-[(2-isopropylaminoethylimino)methyl]phenol (HL), derived from 3-bromosalicylaldehyde with N-isopropylethane-1,2-diamine, and its zinc(II) and nickel(II) complexes [Zn(HL)₂(NCS)₂] (I) and [Ni(HL)₂(N₃)₂)] · 0.25H₂O (II) have been prepared and characterized by elemental analyses, IR, and single crystal X-ray crystallographic determination. The crystal of I is orthorhombic: space group Pbca, a = 13.6928(9), b = 9.7203(6), c = 22.926(1) Å, V = 3051.4(3) Å^{3, Z} = 4. The crystal of II is triclinic: space group $P\bar 1$ , a} = 8.0212(7), b = 12.744(1), c = 15.590(2) Å, α = 104.802(3)°, β = 90.561(3)°, γ = 103.130(3)°, V = 1496.6(2) Å^{3, Z} = 1. The zwitterionic Schiff base ligands coordinate to the metal atoms through phenolate O, imine N, and amine N atoms. Each metal atom in the complexes is in octahedral coordination. The effect of these complexes on the antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans were studied.     

Synthesis and crystal structures of two Schiff base copper(II) complexes derived from 4-chloro-2-[(2-morpholin-4-ylethylimino)methyl]phenol

A centrosymmetric mononuclear copper(II) complex, [Cu(L¹)₂] (I), and a phenolate oxygen-bridged dinuclear copper(II) complex, [Cu₂(L²)₄] (II) (HL¹ = 4-chloro-2-[(2-morpholin-4-ylethylimino)methyl]phenol, HL² = 4-chloro-2-(cyclohexylimino-methyl)phenol), were synthesized and characterized by elemental analyses, IR, and single crystal X-ray diffraction. The crystal of I is monoclinic: space group {ITP}2₁/n, a = 13.396(3), b = 5.339(1), c = 19.740(4) Å, β = 108.64(3), V = 1337.8(5) ų, {ITZ} = 2. The crystal of II is monoclinic: space group P2₁, a = 9.157(2), b = 22.715(4), c = 12.169(2) Å, = 95.28(3), {ITV} = 2520.4(8) Å3, {ITZ}= 2. The Cu atom in I, lying on the inversion center, is four-coordinate in a square planar geometry with two phenolate oxygen and two imine nitrogen atoms. Each Cu atom in II is five-coordinate in a square pyramidal geometry with two phenolate oxygen and two imine nitrogen atoms from two L² ligands defining the basal plane and with one phenolate oxygen atom of another L² ligand occupying the apical position.     

Synthesis, crystal structures, and biological activity of zinc(II) complexes derived from 4-bromo-2-[(3-diethylaminopropylimino)methyl]phenol

Two new Schiff base zinc(II) complexes, [ZnBr₂L] (I) and [ZnCl₂L] (II), where L is 4-bromo-2-[(3-diethylaminopropylimino)methyl]phenol, were synthesized and characterized by physico-chemical methods and single crystal X-ray diffraction. The crystal of I is monoclinic: space group P2₁/n a = 7.250 (2), b = 16.136 (3), c = 15.802 (3) Å, β = 90.027 (3)°, V = 1848.6 (7) ų, Z = 4. The crystal of II is monoclinic: space group P2₁/n, a = 7.177 (3), b = 15.970 (4), c = 15.689 (3), β = 91.674 (3)°, V = 1797.5 (9) ų, Z = 4. The Zn atom in each complex is four-coordinated by one phenolate O and one imine N atoms of the Schiff base ligand and two halide atoms, forming a tetrahedral coordination. The urease inhibitory activities of the complexes were evaluated.     

Syntheses and crystal structures of copper(II) and nickel(II) complexes derived from 2-bromo-4-chloro-6-[(2-methylaminoethylimino)methyl]phenol

A new centrosymmetric mononuclear copper(II) complex [Cu(L)₂](ClO₄)₂ (I) and a new centrosymmetric mononuclear nickel(II) complex [Ni(L)₂(MeOH)₂](ClO₄)₂ (II), where L is the zwitterionic ligand 2-bromo-4-chloro-6-[(2-methylammonioethylimino)methyl]phenolate, have been prepared from the Schiff base 2-bromo-4-chloro-6-[(2-methylaminoethylimino)methyl]phenol with copper perchlorate and nickel perchlorate, respectively. The complexes were characterized by elemental analysis, infrared spectra, and single-cyrstal X-ray diffraction (CIF files CCDC nos. 1408054 (I) and 1407973 (II)). Complex I crystallizes in the monoclinic space group P2₁/c with unit cell dimensions a = 7.7736(4), b = 21.608(1), c = 8.5194(4) Å, β = 93.907(2)°, V = 1427.7(1) ų, Z = 2, R ₁ = 0.0546, and wR ₂ = 0.1531. Complex II crystallizes in the monoclinic space group P2₁/c with unit cell dimensions a = 21.324(3), b = 16.821(2), c = 9.425(1) Å, β = 90.114(2)°, V = 3380.5(7) ų, Z = 4, R ₁ = 0.0693, and wR ₂ = 0.1627. The Cu atom in I is in square planar coordination, and the Ni atom in II is in octahedral coordination.     

Synthesis and crystal structure of polymeric thiocyanato-bridged copper(II) complex with 4-nitro-2-[(2-piperidin-1ylethylimino)methyl] phenolate

A polymeric thiocyanato-bridged Schiff base copper(II) complex [Cu(L)(NCS)] _n , where L is 4-nitro-2-[(2-piperidin-1-ylethylimino)methyl]phenolate, has been synthesized and structurally characterized by elemental analysis, infrared spectra, and single crystal X-ray diffraction. The complex crystallizes in the monoclinic space group P2₁ with a = 8.527(5), b = 10.296(6), c = 9.697(6) Å, β = 103.77(2)°, V = 826.8(8) ų, Z = 2. In the complex, the Cu atom is in a square pyramidal coordination with one O and two N donor atoms of the Schiff base ligand and with one thiocyanate N atom, defining the basal plane, and with one symmetry related thiocyanate S atom occupying the apical position. The thiocyanate ligand links the Cu atoms through the end-to-end bridging mode.     

Synthesis and Crystal Structure of 4-Nitro-2- [（2-diethylaminoethylimino）methyl]phenol

1 INTRODUCTION Schiff base ligands have played an important role in the development of coordination chemistry as they readily form stable complexes with most metal ions[1～4]. These complexes are very interesting in many fields, such as catalysis and enzymatic reac- tions[5, 6], magnetism and molecular architectures[7～9]. The complexes derived from the similar tridentate Schiff base ligand 2-[(2-dimethylaminoethylimino)- methyl]phenol[10, 11] and its derivatives[12～14] have been widely …     

Synthesis,crystal structures,and antibacterial activities of two copper(II) complexes derived from 1-[(2-morpholin-4-ylethylimino)methyl]-naphthalen-2-ol

A trinuclear complex, [Cu(Cu(μ-Br)₂L)₂], and a dinuclear complex, [Cu₂(μ-Cl)₂L₂], have been synthesized with the tridentate Schiff base 1-[(2-morpholin-4-ylethylimino)methyl]-naphthalen-2-ol (HL), derived from 2-hydroxy-1-naphthyaldehyde and 4-(2-aminoethyl)morpholine. Both complexes have been characterized by physicochemical and spectroscopic methods. [Cu(Cu(μ-Br)₂L)₂] is a centrosymmetric bromide and phenolate oxygen-bridged trinuclear compound, while complex [Cu₂(μ-Cl)₂L₂] is a centrosymmetric-chloride-bridged dinuclear compound. The central Cu(II) atom in [Cu(Cu(μ-Br)₂L)₂] is six-coordinated in an octahedral coordination, while other Cu(II) atoms in both complexes are five-coordinated in square-pyramidal coordinations. Both complexes and HL were tested in vitro for their antibacterial activities.     

Synthesis and Crystal Structure of Diaquabis{2,4-dibromo-6-[(2-ethylaminoethylimino)methyl]-phenolato}nickel(Ⅱ) Dinitrate Diacetonitrile

The title mononuclear Schiff base nickel(Ⅱ) complex [Ni(C11H14Br2N2O)2(H2O)2]· 2NO3·2C2H3N was prepared and characterized by elemental analysis,IR spectrum,and single-crystal X-ray diffraction. The crystal belongs to the monoclinic system,space group P21/n with a=15.534(2),b=7.647(1),c=16.435(2),β=103.252(2)o,V=1900.3(4)3,Z=2,Dc=1.750 g/cm3,Mr=1000.99,λ(MoKα)=0.71073,μ=4.776 mm-1,F(000)=996,the final R=0.0368 and wR=0.0724. A total of 3988 unique reflections were collected,of which 2764 with I > 2σ(I) were observed. The complex consists of a mononuclear [Ni(C11H14Br2N2O)2(H2O)2]2+ cation,two nitrate anions and two acetonitrile molecules. The Ni atom,lying on the inversion centre,is six-coordinated by two Schiff bases and two water molecules to assume an octahedral coordination geometry. The molecules in the crystal are linked through intermolecular hydrogen bonds of N–H…O,N–H…Br,O–H…O,O–H…N and C–H…O to form layers.     

Synthesis,crystal structures,and antibacterial activity of copper(II) and cobalt(III) complexes derived from 2-[(2-dimethylaminoethylimino)methyl]-4-methylphenol

A new tetranuclear copper(II) complex (I) and a new mononuclear cobalt(III) complex (II) have been synthesized from the Schiff base compound 2-[(2-dimethylaminoethylimino)methyl]-4-methylphenol. The complexes have been characterized by physico-chemical and spectroscopic methods, as well as single crystal X-ray determination (CIF files CCDC nos. 1447778 (I) and 1447779 (II)). The Cu atoms in complex I are in square pyramidal coordination, and the Co atom in complex II is in octahedral coordination. Crystal structures of the complex are stabilized by hydrogen bonds and π···π interactions. The complexes and the Schiff base compound were assayed for antibacterial activities against three Gram-positive bacterial strains (B. subtilis, S. aureus, and St. faecalis) and three Gram-negative bacterial strains (E. coli, P. aeruginosa, and E. cloacae) by MTT method. As a result, the complexes showed effective antimicrobial activity against the microorganisms tested.     

Solvent-influenced syntheses and crystal structures of two azido-bridged polynuclear copper(II) complexes derived from 2-[(3-methylaminopropylimino)methyl]phenol with urease inhibitory activities

An end-on azido-bridged dinuclear Cu(II) complex, [Cu₂L₂(μ_1,1–N₃)₂]·CH₃OH, and an end-on azido-bridged polynuclear Cu(II) complex, [CuL(μ_1,1–N₃)]_n, derived from the Schiff base 2-[(3-methylaminopropylimino)methyl]phenol (HL), were synthesized and characterized by physico-chemical and spectroscopic methods. The two complexes were synthesized and crystallized with different solvents, methanol for [Cu₂L₂(μ_1,1–N₃)₂]·CH₃OH and ethanol for [CuL(μ_1,1–N₃)]_n. The Cu atom in each complex is five-coordinate in a square pyramidal geometry with one O and two N atoms of L, and one N atom of an azide ligand defining the basal plane, and with one N atom of another azide ligand occupying the apical position. The urease inhibitory activities of both complexes were evaluated.     

Synthesis, structures, and antimicrobial activity of nickel(II) and Zinc(II) complexes with 5-methoxy-2-[(3-methylaminopropylimino)methyl]phenol

The Schiff base 5-methoxy-2-[(3-methylaminopropylimino)methyl]phenol (MMP) derived from 4-methoxysalicylaldehyde and N-methylpropane-1,3-diamine and its nickel(II) and zinc(II) complexes [Ni(MMP)₂(NCS)₂] (I) and [ZnCl₂(MMP)] (II), have been prepared and characterized by elemental analyses, IR, and single crystal X-ray crystallographic determination. The crystal of I is monoclinic: space group P2₁/c, a = 9.0488(8), b = 12.7768(12), c = 12.9232(11) Å, β = 101.927(5)°, V = 1461.9(2) ų, Z = 2. The crystal of II is orthorhombic: space group Pbca, a = 11.6991(7), b = 13.2839(8), c = 20.4451(12) Å, V = 3177.4(3) ų, Z = 8. The Schiff base coordinates to the metal atoms through the phenolate O and imine N atoms. The effect of these complexes on the antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans were studied.     

Syntheses,crystal structures,and urease inhibitory properties of copper(II) and zinc(II) complexes with 2-bromo-4-chloro-6-[(2-dimethylaminoethylimino)methyl]phenol

A new copper(II) complex, [CuL(μ _1,1-N₃)] _n (1), and a new zinc(II) complex, [ZnL(μ ₂-acetato-O, O′)₂] _n (2) (HL = 2-bromo-4-chloro-6-[(2-dimethylaminoethylimino)methyl]phenol), were prepared and characterized by elemental analyses, infrared spectroscopy, and single-crystal X-ray diffraction. Complex 1 is an end-on azide-bridged polynuclear copper(II) complex and 2 is a syn–anti bidentate acetate-bridged polynuclear zinc(II) complex. Each metal in the complex is five-coordinate with square-pyramidal geometry. Complex 1 shows good urease inhibitory properties, while 2 does not.     

Crystal structures of bis(AZIDO)bis(2-morpholin-4-ylethylamino)copper(II) and bis{2,4-dibromo-6-[(2-morpholin-4-ylethylimino)methyl] phenolato}copper(II)

Two new copper(II) complexes [Cu(MEA)₂(N₃)₂] (1) and [Cu(BMP)₂] (2), where MEA and BMP are 2-morpholin-4-ylethylamine and 2,4-dibromo-6-[(2-morpholin-4-ylethylimino)methyl]phenolate respectively, are prepared and characterized using elemental analysis, FT-IR spectroscopy, and X-ray single crystal diffraction. The crystal of 1 belongs to the triclinic system, space group P-1, with a = 6.661(2) Å, b = 8.440(3) Å, c = 8.913(3) Å, α = 102.032(3)°, β = 107.899(2)°, γ = 98.242(3)°, V = 454.6(3) ų, Z = 1, D _c = 1.490 g/cm³, R ₁ = 0.0226, and wR ₂ = 0.0564. The crystal of 2 belongs to the monoclinic system, space group P2₁/c, with α = 7.0707(7) Å, b = 15.438(1) Å, c = 14.227(1) Å, β = 96.659(2)°, V = 1542.5(3) ų, Z = 2, D _c = 1.821 g/cm³, R ₁ = 0.0437, and wR ₂ = 0.1041. In each complex, the Cu atom is in a square planar coordination. The molecules of 1 are linked through intermolecular N-H...N and N-H...O hydrogen bonds to form layers parallel to the ab plane. The molecules of 2 are linked through intermolecular C-H...Br hydrogen bonds to form a 3D network.     

Synthesis and crystal structures of cobalt(III) and zinc(II) complexes derived from 4-chloro-2-[(2-morpholin-4-ylethylimino)methyl]phenol with urease inhibitory activity

A new mononuclear cobalt(III) complex, [CoL₂(N₃)]₂ · CH₃OH (I), and a new mononuclear zinc(II) complex, [ZnLCl(CH₃OH)] (II) (HL = 4-chloro-2-[(2-morpholin-4-ylethylimino)methyl]phenol), were prepared and structurally characterized by elemental analyses, infrared spectroscopy, and single- crystal X-ray diffraction. The crystal of I is monoclinic: space group P2₁/c, a = 18.742(2) Å, b = 15.197(2) Å, c = 25.646(2) Å, β = 125.996(3)°, V = 5909.8(11) ų, Z = 4. The crystal of II is monoclinic: space group P2₁/c, a = 7.257(1) Å, b = 24.707(2) Å, c = 9.637(1) Å, β = 101.557(2)°, V = 1692.9(3) ų, Z = 4. The Co atom in I is in an octahedral coordination, and the Zn atom in II is in a trigonal-bipyramidal coordination. The urease inhibitory test shows that complex I has strong urease inhibitory activity, while complex II has no activity.     

Crystal structures of nitrato-{4-bromo-2-[(2-hydroxyethylimion)methyl]phenolo}-(3,5-Dibromopyridine)copper and nitrato-{2,4-dibromo-6-[(2-hydroxyethylimino)methyl]phenolo}-(3,5-dibromopyridine)copper

The crystal structures of nitrato-{4-bromo-2-[2-hydroxyethylimino)methyl]phenolo}-(3,5-dibromopyridine)copper (I) and nitrato-{2,4-dibromo-6-[(2-hydroxyethylimino)methyl]phenolo}-(3,5-dibromopyridine)copper (II) are determined. The crystals of compound I are orthorhombic: a = 14.157(3) Å, b = 15.420(3) Å, c = 17.494(4) Å, space group Pbca, Z = 8, R = 0.067. The crystals of compound II are monoclinic: a = 10.675 Å, b = 13.973 Å, c = 14.007 Å, β = 111.92°, space group P2₁/n, Z = 4, R = 0.0464. In the structures of compounds I and II, the copper atom coordinates, correspondingly, singly deprotonated 4-bromo-2-[(2-hydroxyethylimino)methyl]phenol and 2,4-dibromo-6-[(2-hydroxyethylimino)methyl]phenol molecules, and 3,5-dibromopyridine, and the nitrate ion. The coordination polyhedron of the copper ion in complexes I and II is a slightly distorted tetragonal pyramid. The bases of the pyramids are formed by the imine and pyridine nitrogen atoms and the phenolic and alcoholic oxygen atoms, and the axial vertices are occupied by the oxygen atoms of the monodentate nitrato groups. In the complexes under study, the six-membered metallocycles have asymmetric gauche conformation. In crystal, complexes I are united, due to the slip plane a, through bifurcate hydrogen bonds into infinite chains along the direction [100]. Complexes II in crystal form two-dimensional networks by means of hydrogen bonds.     

Synthesis and crystal structures of two zinc(II) complexes derived from 4-bromo-2-(cyclopentyliminomethyl)phenol with different solvents

Two new mononuclear zinc(II) complexes, [ZnL₂] (I) and [ZnL₂] · 2MeOH (II) (HL = 4-bromo-2-(cyclopentyliminomethyl)phenol), were synthesized by the reaction of the Schiff base HL with zinc acetate in ethanol and methanol solutions, respectively. Both complexes were characterized by elemental analyses and single-crystal X-ray diffraction. The crystal of I is orthorhombic: space group Pbca, a = 14.711(3), b = 13.223(3), c = 24.870(5) Å, V = 4837.8(18) ų, Z = 8. The crystal of II is monoclinic: space group C2/c, a = 20.581(5), b = 10.660(3), c = 15.428(4) Å, β = 119.919(3)°, V = 2933.7(13) ų, Z = 4. The Zn atom in each complex is four-coordinated by two imine N and two phenolic O atoms, forming a tetrahedral geometry. Complex II possesses crystallographic two-fold rotation axis symmetry.     

The anion-directed self-assembly of manganese complexes derived from 2-ethoxy-6-[(2-phenylaminoethylimino)methyl]phenol

The mixed valence manganese(II/IV) complex, [Mn^IIL₂(MeOH)₂]·[Mn^IVL₂(OAc)₂]·2(MeOH) (1), and the chloride-bridged 1D polymeric manganese(III) complex, [Mn^IIIL₂(μ-Cl)]_n (2), where L is the deprotonated form of 2-ethoxy-6-[(2-phenylaminoethylimino)methyl]phenol (HL), have been prepared and structurally characterized by single-crystal X-ray diffraction analysis and IR spectra. The Mn atoms in both complexes are octahedrally coordinated. The self-assembly of the complex structures is apparently directed by the anions of the manganese salts.