Preparation and characterization of binuclear CuII complexes derived from diamines and dialdehydes

New macrocyclic complexes were synthesized by template reaction of 1,7-bis(2-formylphenyl)-1,4,7-trioxaheptane, 1,4-bis(2-carboxyaldehydephenoxy)butane or 1,3-bis(2-carboxyaldehydephenoxy)propane with 1,4-bis(2-aminophenoxy)butane, 1,3-bis(2-aminophenoxy)butane, 1,4-bis(4-chloro-2-aminophenoxy)butane or 1,3-bis(4-chloro-2-aminophenoxy)butane and Cu(NO₃)₂ ·?3H₂O or Cu(ClO₄)₂ ·?6H₂O, respectively. The complexes have been characterized by elemental analysis, IR, ¹H and ¹³C NMR, UV–Vis spectra, magnetic susceptibility, conductivity measurements and mass spectra. All complexes are diamagnetic and binuclear.     

Linear oxalato- and 4,4′-dipyridyldisulfide-bridged copper(II) coordination polymer involving in situ ligand synthesis

The reaction of 1,3-bis(pyridyl-4-ylthio)propan-2-one with Cu(ClO₄)₂?·?6H₂O gave a new complex {[Cu₂(4PDS)₂(ox)(H₂O)₄](ClO₄)₂} _n (4PDS?=?4,4′-dipyridyldisulfide, ox?=?oxalate), with 4PDS and ox being created by the Cu(II)-assisted oxidation of 1,3-bis(pyridyl-4-ylthio)propan-2-one. The complex determined by X-ray crystallography is a 1D polymer, in which metallacycles formed by two 4PDS and two Cu(II) ions are further bridged through ox anions. It crystallizes in the orthorhombic system, space group Fddd, with lattice parameters a?=?15.106(2), b?=?23.667(4), c?=?27.637(3)?Å and Z?=?8.     

Synthesis and spectral studies of macrocyclic Cu(II) complexes by reaction of various diamines,copper(II) perchlorate and 1,4-bis(2-carboxyaldehyde phenoxy)butane

Six macrocyclic complexes, were synthesized by reaction of 1,4-bis(2-carboxyaldehyde phenoxy)butane and various amines and their copper(II) perchlorate complexes were synthesized by template effect reaction of 1,4-bis(2-carboxyaldehyde phenoxy)butane, Cu(ClO₄)₂?·?6H₂O and amines. The metal-to-ligand ratios were found to be 1?:?1. Cu(II) metal complexes are 1?:?2 electrolytes as shown by their molar conductivities (Λ_M) in DMF (dimethyl formamide) at 10^?3?M. The Cu(II) complexes are proposed to be square planar based on elemental analysis, FT–IR, UV–Vis, magnetic susceptibility measurements, molar conductivity measurements, and mass spectra.     

Synthesis,characterization, and fluorescence properties of dinuclear cadmium(II) complexes

Four dinuclear cadmium(II) complexes, [Cd₂(L¹)(μ₂-Cl)Cl₂] (1), [Cd₂(L²)(μ₂-Cl)Cl₂] (2), [Cd₂(L³)(μ₂-Cl)Cl₂] (3), and [Cd₂(L⁴)₃ClO₄] (4), where HL¹ = 4-methyl-2,6-bis(1-(2-piperidinoethyl)iminomethyl)-phenol, HL² = 4-methyl-2,6-bis(1-(2-pyrrolidinoethyl)iminomethyl)-phenol, HL³ = 4-methyl-2,6-bis(1-(2-morpholinoethyl)iminomethyl)-phenol and HL⁴ = 4-methyl-2,6-bis(cyclohexylmethyl)iminomethyl)-phenol, were synthesized. They were characterized by elemental analysis, FT-IR, UV–Vis, fluorescence and electronspray ionization mass spectroscopy. Complexes 1 and 4 were also characterized by single crystal X-ray analysis. The cadmiums atoms in 1 are linked by μ₂-chloride in a distorted square pyramidal geometry, whereas cadmium atom in 4 is in a distorted octahedral environment. The complexes show emission bands around 500 nm with excitation at 395 nm.     

Synthesis and characterization of a new pyrrolidine containing sulfur ligand and the transition metal complexes of Co(II), Ni(II) and Cu(I)

Potassium 1,3-dipyrrolidinopropan-2-O-xanthate (LK), and its complexes with Co(II), Ni(II) and Cu(I) have been prepared and characterized as [CoL₂(H₂O)₂]?·?2H₂O, [NiL₂(H₂O)₂] and CuL?·?2H₂O by FT-IR, ¹H and ¹³C NMR spectroscopies, elemental analyses, magnetic susceptibility and TGA techniques.     

Syntheses,structural characterizations and microbial activities of Ni(II) and Zn(II) 5-aminoisophthalate coordination polymers

Two coordination polymers with 5-aminoisophthalic acid (H₂aip), [Ni(μ-aip)(H₂O)₂(tmeda)]_n (1) and {H₂dap[Zn₂(μ-aip)(μ₃-aip)₂]?9H₂O}_n (2) (H₂aip = 5-aminoisophthalic acid, tmeda = N,N,N′-N′-tetramethylethylenediamine, dap = 1,3-diaminopropane) have been synthesized. Elemental and thermal analyses, magnetic susceptibilities, IR, AAS, mass and UV–vis spectroscopic studies have been performed to characterize the compounds. Nickel(II) has octahedral geometry by two oxygens of different carboxylates, bidentate, tmeda as bidentate chelating and two water ligands. Zn(II) has tetrahedral geometry by three oxygens of different carboxylate groups and one nitrogen by amine of aip. 1 crystallizes in the orthorhombic crystal system with space group Pccn and 2 in monoclinic crystal system with space group P2₁/c. Complex 2 exhibits photoluminescence properties in the solid state at room temperature. This study determined the susceptibility patterns of 1 and 2 against bacterial, yeast and mold micro-organisms. Antimicrobial activities were done on 12 different micro-organisms using the micro-dilution method. Tested microbial species were inhibited by 1 with a Minimum inhibitory concentrations (MIC) of 375–3000 μg mL^?1. Compound 2 showed antimicrobial activities against tested micro-organisms with a MIC of 188–1500 μg mL^?1. Compound 2 showed antibacterial activity against Legionella pneumophila sg1 375 μg mL^?1 (MIC value).     

A holodirected Pb(II) architecture based on bifunctional tetrazole-carboxylate and photoluminescence

A new 1-D Pb(II) complex {[Pb₂(H₂O)₄(tppbc)₂]?·?(CH₃)₂NCHO} _n (1) based on tetrazole-carboxylate bifunctional ligand has been prepared and characterized (tppbc?=?3-(4-(2-(1H-tetrazol-5-yl)phenyl-4-yl)phenyl)-2-ethoxy-3H-benzimidazole-4-carboxylic acid). Photo-luminescence measurements indicate that although the fluorescence of tppbc is quenched after coordination, the Pb(II) complex shows strong intense phosphorescence emission. Lifetimes at 298?K and low temperatures agree with the large Stokes shift of 1.     

Syntheses and structures of three new coordination polymers with the flexible 1,4- bis (imidazol-1-yl)butane ligand

Three new coordination polymers [Co(bimb)₂(NCS)₂] _n (1), {[Co(bimb)₂(dca)₂]?·?CH₃CN} _n (2) and [Cu(bimb)₂(NO₃)₂] _n (3) (bimb?=?1,4-bis(imidazol-1-yl)butane, dca?=?dicyanamide) were synthesized and characterized. In 1, each Co(II) links two Co(II)'s by double bimb ligands and extends to form a one-dimensional chain containing the Co₂(bimb)₂ 22-membered metallocycle. 2 and 3 are two-dimensional (4, 4) networks linked by bimb bridges. The conformations of the bimb ligands in 1, 2 and 3 are analyzed.     

Complexes of substituted dipyridylpyridazines with palladium(II) and platinum(II)

Reactions of 3,6-bis(2′-pyridyl)pyridazine derivatives (n-dppn)¶ ¶For the n-dppn ligands, n stands for the size of the cyclic aliphatic ring on positions 4 and 5 of the pyridazine ring, n?=?5, 6, 8, and 12. with MX₂(PhCN)₂ (M?=?Pd, Pt; X?=?Cl,?Br) have been investigated. The new complexes cis-[PdCl₂(n-dppn)] (n?=?5,?6,?8,?12), cis-[PtCl₂(n-dppn)]?·?H₂O (n?=?5,?6), cis-[PtCl₂(8-dppn)] and cis-[PtBr₂(5-dppn)] have been characterized by elemental analyses, conductivity measurements, infrared, electronic and ¹H-NMR spectra.     

Dinuclear Zn(II) and Hg(II) complexes of an angular dipyridyl ligand: syntheses,crystal structures,and properties

The angular polytopic dipyridyl ligand 2,6-bis(quinoline-2-carboxamido)pyridine (H₂L) was prepared. Assemblies of H₂L with ZnAc₂ and HgAc₂ resulted in two new dinuclear complexes [Zn₂(L)(Ac)₂]?·?1.5H₂O?·?0.5CH₃OH (1) and [Hg₂(L)(Ac)₂]?·?5H₂O?·?CH₃OH (2) where the doubly deprotonated L^2? bi-chelate as μ-kN,N′?:?kN″,N″′, bridging the two metal centers (Ac?=?acetate). In 1, the two Zn(II) ions are also doubly bridged by two Ac ions in a μ-kO?:?kO′ coordination, and thus each metal center adopts a distorted tetrahedral geometry. In 2, each Ac ion is only terminal to Hg(II), in a rare distorted triangular or T-shaped coordination geometry. Free H₂L, 1, and 2 emit interesting bluish-green fluorescence with strong intensities. Thermogravimetric analysis of 1 shows that the dinuclear structure of 1 is stable to 382°C.     

Synthesis,characterization, and biological properties of Ni(II), Co(II), and Cu(II) complexes of Schiff bases derived from 4-aminobenzylamine

New Schiff bases, N,N′-bis(salicylidene)-4-aminobenzylamine (H₂L¹), N,N′-bis(3-methoxysalicylidene)-4-aminobenzylamine (H₂L²), and N,N′-bis(4-hydroxysalicylidene)-4-aminobenzylamine (H₂L³), with their nickel(II), cobalt(II), and copper(II) complexes have been synthesized and characterized by elemental analyses, electronic absorption, FT-IR, magnetic susceptibility, and conductance measurements. For the ligands, ¹H and ¹³C NMR and mass spectra were obtained. The tetradentate ligands coordinate to the metal ions through the phenolic oxygen and azomethine nitrogens. The keto-enol tautomeric forms of the Schiff bases H₂L¹, H₂L², and H₂L³ have been investigated in polar and apolar solvents. All compounds were non-electrolytes in DMSO (～10^?3 M) according to the conductance measurements. Antimicrobial activities of the Schiff bases and their complexes have been tested against Acinobacter baumannii, Pseudomonas aeruginosa, Micrococcus luteus, Bacillus megaterium, Corynebacterium xerosis, Staphylococcus aureus, Escherichia coli, Candida albicans, Rhodotorula rubra, and Kluyveromyces marxianus by the disc diffusion method; biological activity increases on complexation.     

Synthesis and structural characterization of new trinuclear cobalt(II) and nickel(II) complexes possessing five- and six-coordinated geometry

Tri-nuclear cobalt and nickel complexes ([(CoL)₂(OAc)₂Co]?·?THF (I) and [(NiL)₂(OAc)₂(THF)₂Ni]?·?THF (II)) have been synthesized by reaction of a new Salen-type bisoxime chelating ligand of 2,2′-[ethylenedioxybis(nitrilomethylidyne)]dinaphthol(H₂L) with cobalt(II) acetate tetrahydrate or nickel(II) acetate tetrahydrate, respectively. Complexes I and II were characterized by elemental analyses, IR, TG-DTA and ¹H-NMR etc. The X-ray crystal structures of I and II reveal that two acetate ions coordinate to three cobalt or nickel ions through M–O–C–O–M (M?=?Co or Ni) bridges and four μ-naphthoxo oxygen atoms from two [ML] units also coordinate to cobalt(II) or nickel(II). Complex I has two distorted square-pyramidal coordination spheres and an octahedral geometry around Co1. In complex II all three nickel ions are six-coordinate.     

Three double- or triple-stranded chains constructed from different cobalt(II) salts and a flexible bis-triazole ligand

Three coordination compounds, {[Co(btrp)₂(H₂O)₂]?·?NO₃?·?H₂O} _n (1), {[Co(btrp)₂(H₂O)₂]?·?H₂O?·?2H₂btc} _n (2), and {[Co(btrp)₃]?·?2ClO₄} _n (3) (btrp?=?1,3-bis(1,2,4-triazol-1-yl)propane; H₃btc?=?benzene-1,3,5-tricarboxylic acid), have been prepared via solvothermal method and characterized by single-crystal X-ray diffraction and elemental analyses. Compound 1 possesses a 1-D double-stranded chain composed of ribbons of 20-membered cycles. Binuclear water clusters link adjacent nitrate anions to form a 1-D supramolecular helix in the structure. Compound 2 has a 1-D double-stranded chain wherein free H₂btc ligands constitute 1-D negative chains through classical hydrogen-bonding interactions (O–H?···?O). Compound 3 exhibits a triple-stranded 1-D chain. For 1–3, 3-D supramolecular structures are consolidated by interchain weak hydrogen-bonding interactions as well as electrostatic interactions.     

Preparation and spectral characterization of new macrocyclic Ni(II) and Co(II) complexes derived from 1,4- bis (2-carboxyaldehydephenoxy)butane and various diamines

Six new macrocyclic complexes were synthesized by the template effect from reaction of 1,4-bis(2-carboxyaldehydephenoxy)butane, Ni(NO₃)₂ · 6H₂O or Co(NO₃)₂ · 6H₂O and various diamines. The metal-to-ligand ratios of Ni(II) or Co(II) metal complexes were found to be 1 : 1. Coordination of the Schiff base to Ni(II) and Co(II) through the two nitrogen and two oxygen atom (ONNO) are expected to reduce the electron density in the azomethine link and hydroxyl group. The Ni(II) and Co(II) complexes are proposed to be tetrahedral and are 1 : 2 electrolytes as shown by their molar conductivities (Λ_M) in DMF (dimethyl formamide) at 10^?3 M. The structures are proposed from elemental analysis, FT-IR, UV-VIS, magnetic susceptibility measurements, molar conductivity measurements, and mass spectra.     

Synthesis and characterization of potassium 1,3-bis(N-methylpiperazino)propan-2-O-xanthate and the complexes of Co(II), Ni(II) and Cu(I) ions

Potassium 1,3-bis(N-methyl piperazino)propan-2-O-xanthate (LK), and its complexes with Co(II), Ni(II) and Cu(I) ions have been prepared and characterized as [CoL₂(H₂O)₂], [NiL₂(H₂O)₂]·2H₂O and CuL·2H₂O by FT-IR, ¹H and ¹³C?NMR spectroscopies, elemental analyses, magnetic susceptibility and TGA techniques.     

Synthesis,Characterization and Crystal Structures of Four Dinuclear Schiff Base Nickel(II) and Copper(II) Complexes with Versatile Bridging Groups

Four novel Schiff base nickel(II) and copper(II) complexes, derived from the end‐on (μ_1,1‐N₃) azide, end‐to‐end (μ_1,3‐NCS) thiocyanate, or phenolate oxygen bridges, have been synthesized and their crystal structures determined by X‐ray diffraction methods. They are the dinuclear double end‐on azide‐bridged [Ni₂(L1)₂(MeCN)₂(μ_1,1‐N₃)₂]·MeOH ( 1 ), the dinuclear double end‐on azide‐bridged [Ni₂(L2)₂(MeOH)₂(μ_1,1‐N₃)₂][Ni₂(L2)₂(OH₂)₂(μ_1,1‐N₃)₂]·MeOH ( 2 ), the dinuclear double end‐to‐end thiocyanate‐bridged [Cu₂(L3)₂(μ_1,3‐NCS)₂] ( 3 ), and the dinuclear double phenolate O‐bridged [Cu₂(L4)₂(NCS)₂] ( 4 ), where HL1, HL2, HL3 and HL4 are four tridentate Schiff bases obtained by the condensation of 3,5‐dibromosalicylaldehyde with N‐ethylethane‐1,2‐diamine, of 3,5‐dichlorosalicylaldehyde with N‐methylpropane‐1,3‐diamine, of 3‐bromo‐5‐chlorosalicylaldehyde with 2‐aminomethylpyridine, and of 5‐nitrosalicylaldehyde with 2‐aminomethylpyridine, respectively. Each nickel(II) atom in 1 and 2 is in an octahedral coordination, while each copper(II) atom in 3 and 4 is in a square pyramidal coordination. There exists crystallographic inversion centre symmetry in each of the complexes.     

Synthesis,crystal structure and catalytic performance of bis (imino)pyridyl nickel complexes

Two new Ni(II) complexes of 2,6-bis[1-(2,6-diethylphenylimino)ethyl]pyridine (L¹), 2,6-bis[1-(4-methylphenylimino)ethyl]pyridine (L² ) have been synthesized and structurally characterized. Complex Ni(L¹)Cl₂?·?CH₃CN (1), exhibits a distorted trigonal bipyramidal geometry, whereas complex Ni(L¹)(CH₃CN)Cl₂ (2), is six-coordinate with a geometry that can best be described as distorted octahedral. The catalytic activities of complexes 1, 2, Ni{2,6-bis[1-(2,6-diisopropyl-phenylimino)ethyl]pyridine} Cl₂?·?CH₃CN (3), and Ni{2,6-bis[1-(2,6-dimethylphenylimino) ethyl]pyridine}Cl₂?·?CH₃CN (4), for ethylene polymerization were studied under activation with MAO.     

Synthesis,characterization and comparative studies of mono- and dimeric copper(II) complexes containing tripodal ligands

Mono and dimeric bromo-bridged copper(II) complexes of the type [CuBr₂(L)] and [Cu₂Br₂(L)₂](ClO₄)₂ containing nitrogen donor tripodal ligands L = 2,6-bis(pyrazol-1-yl)pyridine (bppy) or 2,6-bis(3,5-dimethylpyrazol-1-yl)pyridine (dmbppy) have been synthesized. All complexes have been characterized by elemental analysis, IR, ESR and electronic spectra and magnetic susceptibility and cyclic voltammetry measurements.     

Synthesis and spectroscopic characterization of bis(N-alkyldithiocarbamato)nickel(II) complexes: crystal structures of [Ni(S2CNH(n-Pr))2] and [Ni(S2CNH(i-Pr))2]

Bis(N-alkyldithiocarbamato)nickel(II) complexes (1–5) [Ni(S₂CNHR)₂] (where R?=?Me, Et, n-Pr, i-Pr, n-Bu) were synthesized by the reaction of NiCl₂?·?6H₂O and the corresponding sodium salt of N-alkyldithiocarbamate in 1?:?2 molar ratio in aqueous medium. These bis(N-alkyldithiocarbamato)nickel(II) complexes (1–5) were characterized by elemental analysis, UV-Visible, IR, and ¹H/¹³C-NMR spectroscopy. The crystallographic investigation of [Ni(S₂CNH(n-Pr))₂] (3) and [Ni(S₂CNH(i-Pr))₂] (4) revealed distorted square-planar geometry around nickel(II). The dithiocarbamates have anisobidentate coordination with nickel and the dithiocarbamates are trans.     

Synthetic and spectroscopic characterization of Rh(I)-( S )-amino acid complexes with diphosphine and triphosphine ligands

Reaction of [Rh(η⁴-cod)(S)-amino-acidato] ((S)-amino acidate?=?(S)-O₂C-CHR-NH₂; cod?=?cycloocta-1,5-diene) with 1,2-bis(diphenylphosphino)ethane (dppe) affords the ionic [Rh(dppe)₂]{(S)-O₂C-CHR-NH₂} (R?=?Me, I; Ph, II) complexes. Reactions with 1,3-bis(diphenylphosphino)propane (dppp) or 2,2,2-tris(diphenylphosphinomethyl)ethane (triphos) give the neutral [Rh(dppp){(S)-O₂C-CHR-NH₂}] (R?=?Me, III; Ph, IV) or [Rh(η²-triphos){(S)-O₂C-CHR-NH₂}] (R?=?Me, V; Ph, VI) complexes. The complexes are characterized by elemental analysis, UV–Vis-, IR-, ¹H/³¹P{¹H} NMR- and mass-spectroscopy. Two molecules of dppe coordinate to the Rh(I) symmetrically by replacing both cod and (S)-amino acidate to give I–II. Only one molecule of dppp (or triphos) coordinate to the Rh(I) asymmetrically by replacing only cod to give III–VI. Two diastereomeric Rh(I)-complexes are present in V and VI. The results further suggest that the ligands are arranged in a distorted square planar geometry around the Rh(I) centre. The use of triphos instead of dppe or dppp yields the same coordination sphere.