Coordination compounds of some 3d metals with 3-methyl-1-phenyl-4-formylpyrazol-5-one

CuL₂ · 1.5H₂O and ML₂ · 2H₂O · 2EtOH (M = Co²⁺, Ni²⁺, Mn²⁺) coordination compounds were synthesized via the exchange reaction between the sodium salt of 3-methyl-1-phenyl-4-formylpyrazol-5-one (HL) and metal chlorides.The synthesized compounds were studied by thermogravimetry, magnetochemistry, and electron and IR spectroscopy. The complexes CuL₂ · 2Py and CoL₂ · 2Py · MeOH were obtained via recrystallization from a methanol-pyridine mixture, and their structures were studied by X-ray diffraction. Pyrazolone was found to be coordinated in the deprotonated enol form and to form six-membered chelate rings with a metal. The coordination polyhedron of a metal cation was found to be a square bipyramid (Cu²⁺) or an axially elongated octahedron (Co²⁺) with its vertices occupied by the oxygen atoms of 3-methyl-1-phenyl-4-formylpyrazol-5-one and the nitrogen atoms of pyridine.     

2，2′-(1，2-亚乙基双氮次甲基)二喹啉及其Cu2+、 Zn2+、Ni2+、 Mn2+配合物的合成与表征

本文报道2,2′-(1,2-亚乙基双氮次甲基)二喹啉及其与Cu²⁺、 Zn²⁺、 Ni²⁺、 Mn²⁺配合物的合成,并通过元素分析、红外光谱、紫外光谱、X-射线粉末衍射、热分析及核磁共振等手段对配体和配合物进行了表征。配合物的化学组成为M.L.(ClO₄)₂·H₂O(M=Cu²⁺、 Zn²⁺、 Ni²⁺、 Mn²⁺离子;L=C₂₂H₁₈N₄)。     

Synthesis and study of N-(1-phenylethylidene)-N-(4H-1,2,4-triazol-4-yl)amine, N′-(4H-1,2,4-triazol-4-yl)benzamidine, and cobalt(ii), nickel(ii), and copper(ii) complexes based on these ligands

Methods were developed for the synthesis of complexes of Co^II, Ni^II, and Cu^II nitrates and chlorides with N-(1-phenylethylidene)-N-(4H-1,2,4-triazol-4-yl)amine (L¹) and N′-(4H-1,2,4-triazol-4-yl)benzamidine (L²). The Co^II and Ni^II complexes have a linear trinuclear structure. The Cu^II complexes are polynuclear. Both ligands are coordinated to the metal ions in a bidentate-bridging mode through the N(1) and N(2) atoms of the heterocycle. In all compounds, the coordination polyhedron can be described as a distorted octahedron. The molecular and crystal structure of the [Ni₃(L¹)₆(EtOH)₂(H₂O)₄](NO₃)₆·2EtOH·4H₂O complex was established.     

Metal complexes of macrocyclic ligands. Part XXIV. Binuclear complexes with tetraazamacrocycle-N,N′,N″,N‴-tetraacetic acids

The three ligands H₄dota, H₄teta, and H₄heta give binuclear complexes with Cu²⁺ and Ni²⁺, the spectral properties of which have been studied. The structures of Cu₂(dota)·5H₂O and Cu₂(teta)·6H₂O have been established by X-ray diffraction analysis.     

Synthesis and Structures of Four Metal-Organic Coordination Compounds with Isomeric Tripodal Ligands

Four new metal-organic coordination compounds [Ni(L4)₂](ClO₄)₂ · 2H₂O ( 1 ), [Cu₂(L4)₂(H₂O)₂(Cl)](Cl)₃ · 5H₂O ( 2 ), [Cu₂(L3)₂(H₂O)(Cl)](Cl)₂ · (NO₃) · 6H₂O ( 3 ), and [Cu(L3)(H₂O)(NO₃)](NO₃) · H₂O ( 4 ), were synthesized and characterized by X-ray crystallography with two isomeric tripodal ligands N¹-(2-amino-ethyl)-N¹-pyridin-3-ylmethyl-ethane-1,2-diamine (L3) and N¹-(2-amino-ethyl)-N¹-pyridin-4-ylmethyl-ethane-1,2-diamine (L4), respectively. It was found that coordination compound 1 exhibits mononuclear structure, and coordination compound 2 displays a one dimensional (1D) zigzag chain structure. Coordination compound 3 shows interesting cyclic hexanuclear structure, whereas coordination compound 4 is a 1D zigzag chain structure. The results indicate that metal ions, organic ligands, and anions have remarkable influence on the formation and structures of the coordination compounds.     

Synthesis, Spectral and Thermal Analyses of Novel Bi- and Polyhomonuclear Complexes of Pyrimidine Bisazo-dianil Derivatives

Seven new bi‐ and polyhomonuclear transition metal complexes with three polyhydroxlated bisazodianil ligands were synthesized and characterized. The ligands were derived from condensation of 6‐(5‐formyl‐2‐hydroxyphenylazo)‐2,4‐dihydroxypyrimidine with aliphatic diamines (H₈L¹, H₈L² and H₆L³). The data of elemental and thermal analyses, molar conductance measurement, IR, electronic and ESR spectra as well as magnetic moment measurements support the formation of [L¹Co₇Cl₆(H₂O)₁₀]·22H₂O ( 1 ), [H₂L²Mn₆Cl₆(H₂O)₈]·3H₂O·2EtOH ( 3 ), [L²Co₈Cl₈(H₂O)₁₂]·24H₂O ( 4 ), [H₄L³Co₂Cl₂(H₂O)₂]·8H₂O·2EtOH ( 6 ) with a tetrahedral geometry and [H₂L¹Ni₅Cl₄(H₂O)₁₆]·19H₂O·EtOH ( 2 ), [L²Ni₈Cl₈(H₂O)₂₈]·8H₂O·EtOH ( 5 ) with an octahedral geometry while [H₆L³Cu₃(H₂O)₇]Cl₃·10H₂O ( 7 ) has a distorted tetrahedral arrangement. The mode of bonding between the metal ions and the ligand molecules is determined and the metal‐metal interaction was studied. The activation thermo‐kinetic parameters for the thermal decomposition steps of the complexes E*, ΔH*, ΔS*, and ΔG* were calculated.     

Transition Metal Ion-Directed Coordination Polymers with Mixed Ligands: Synthesis,Structure, and Photocatalytic Activity for Hydrogen Production and Rhodamine B Degradation

Three mixed-ligand transition metal coordination polymers with the formula of {[Cu^I₂Cu^II(tpt)₂(L)] · 15H₂O}_n ( 1 ) and {[M₂(H₂O)₅(tpt)(L)] · 6H₂O}_n [M = Ni for 2 and Co for 3 ; tpt = 2,4,6-tris(4-pyridyl)-1,3,5-triazine and L = 3,3'-disulfonyl-4,4'-biphenyldicarboxylate] were hydrothermally synthesized by varying the cheap paramagnetic metal ions and used as photocatalysts for hydrogen evolution from water splitting and rhodamine B (RhB) degradation. Single-crystal structural determinations reveal that 1 is a robust pillared-layer framework with unusual 72-membered {Cu₆(tpt)₆} macrocycle-based layers supported by tetratopic L^4– connectors. Both 2 and 3 are isostructural (4 4) sheets with octahedral Ni^II and Co^II ions extended by ditopic L^4– and tpt linkages, in which the third pyridyl group of tpt is capped by pentahydrated metal ions. Due to the narrowed bandgap and good charge transport of the mixed-valence Cu^I/II centers, 1 exhibits improved dual-functional catalytic activities than 2 and 3 with the visible-light-driven hydrogen evolution rate and RhB degradation efficiency up to 588 μmol · g^–1 · h^–1 and 72 % after 180-minute irradiation. These interesting results indicate the importance of the metal ions and the dimensionality of the coordination polymers on the activity of the non-Pt coordination polymer photocatalytic systems.     

Polyol‐Metall‐Komplexe. 491) μ‐Dulcitolato‐O2, 3;4, 5‐Komplexe mit Amin‐Kupfer(II)‐ und ‐Nickel(II)‐Metallfragmenten

Polyol Metal Complexes. 49¹⁾ μ‐Dulcitolato‐O^{2, 3;4, 5} Complexes with Cu^II(en) and Ni^II(tren) Metal Fragments The dinuclear ethylenediamine‐copper(II) complex of the tetra‐anion of the achiral alditol dulcitol (galactitol) is remarkable, since it was the first crystalline carbohydrate—metal complex ever reported (W. Traube, G. Glaubitt, V. Schenck, Ber. Dtsch. Chem. Ges. 1930 , 63, 2083—2093). Although its existence is recognized for many decades, its structure remained unknown due to a kind of crystal packing that promotes twinning. Crystal growth at low temperatures now yielded crystalline specimens of [(en)₂Cu₂(Dulc2, 3, 4, 5H_—4)] · 7 H₂O ( 1 ) that have allowed us to unravel both the crystal structure and the twinning law. Closely related molecular structures are adopted by [(tren)₂Ni₂(Dulc2, 3, 4, 5H_—4)] · 20 H₂O ( 2 ) and [(Me₃tren)₂Ni₂(Dulc2, 3, 4, 5H_—4)] · 16 H₂O ( 3 ), the latter showing the shortest hydrogen bond towards a polyolate acceptor ever found (O···O distance: 2.422Å).     

Synthesis and Structures of Two Dinuclear Transition Metal Complexes and Their Catalytic Applications in Hydrogenation of Ketones

The complexes [Ni₂(L)₂]₂ · H₂O ( 1 ) and [Cu₂(L)₂(H₂O)] · 2CH₃OH ( 2 ) were prepared by reaction of the chiral Schiff base ligand N‐[(1R,2S)‐2‐hydroxy‐1,2‐diphenyl]‐acetylacetonimine (H₂L) with Ni^II and Cu^II ions, respectively, aiming to develop economically and environmentally‐friendly catalysts for the hydrogenation of ketones. They have a dinuclear skeleton with axial vacant sites. The catalytic effects of the two complexes for hydrogenation of ketones were tested using dihydrogen gas as hydrogen source. They present some catalytic effects in hydrogenation of acetophenone, which has a dependence on the temperature and base used in these reactions. However, no apparent catalytic effects were found for the two complexes in hydrogenation of 4‐nitroacetophenone and 4‐methylacetophenone. Although the catalytic conversion in these hydrogenation reactions is low, they do represent a kind of cheap and environmentally‐friendly hydrogenation catalyst.     

Synthesis and spectral characterization of macrocyclic Schiff base by reaction of 2,6-diaminopyridine and 1,4- bis (2-carboxyaldehydephenoxy)butane and its CuII, NiII, PbII, CoIII and LaIII complexes

A new macrocyclic ligand, 1,3,5-triaza-2,4:7,8:15,16-tribenzo-9,15-dioxacycloheptadeca-1,5-diene (L) was synthesized by reaction of 2,6-diaminopyridine with 1,4-bis(2-carboxyaldehydephenoxy)butane. Then, its Cu^II, Ni^II, Pb^II, Co^III and La^III complexes were synthesized by the template effect by reaction of 2,6-diaminopyridine and 1,4-bis (2-carboxyaldehydephenoxy)butane and Cu(NO₃)₂ · 3H₂O, Ni(NO₃)₂ · 6H₂O, Pb(NO₃)₂, Co(NO₃)₂ · 6H₂O, La (NO₃)₃ · 6H₂O, respectively. The ligand and its metal complexes were characterized by elemental analysis, IR, ¹H- and ¹³C-n.m.r., UV-vis spectra, magnetic susceptibility, thermal gravimetric analysis, conductivity measurements and mass spectra. All complexes are diamagnetic and the Cu^II complex is binuclear. The Co^II complex was oxidised to Co^III.     

Synthesis,Crystal Structure,and Characterization of Two Oxamido‐bridged NiIICuIINiII Heteronuclear Complexes

Two new trinuclear complexes [Cu^II(Ni^IIX₁)₂(C₂H₅OH)₂]· (ClO₄)₂·2(CH₃OH) ( 1 ) and [Cu^II(Ni^IIX₂)₂(H₂O)]·(ClO₄)₂· 0.75(H₂O) ( 2 ) (X₁ = dianion of 5,6;13,14‐dibenzo‐7,12‐bis(ethoxycarboxyl)‐9‐methyl‐2,3‐dioxo‐1,4,8,11‐tetraazacyclotetradeca‐7,11‐diene. X₂ = dianion of 5,6;13,14‐dibenzo‐9,10‐cyclohexano‐7,12‐bis(ethoxycarboxyl)‐2,3‐dioxo‐1,4,8,11‐tetraazacyclotetradeca7,11‐diene.) have been synthesized and characterized by single crystal X‐ray analysis, elemental analysis, IR, UV and EPR spectroscopies. The complexes consist of Ni^IICu^IINi^II heteronuclear cationic entities. The central Cu^II atom of 1 lies in an octahedral coordination environment, while that of 2 resides in a square‐pyramidal coordination sphere. The adjacent trinuclear units of 1 are linked together through π‐π stacking interactions resulting in a 1D supramolecular chain, whereas the π‐π stacking interactions between the contiguous units of 2 lead to a 2D structure. The EPR spectra of the two complexes show a signal of an axially elongated octahedral Cu^II system in 1 and an axially elongated square‐pyramidal Cu^II system in 2 , respectively. The hyperfine splitting of the Cu^II atoms (I^Cu = 3/2) has also been observed in the EPR spectra.     

(μ‐2,6‐Bis{[(2‐hydroxy­phenyl)­(2‐pyri­dyl­methyl)­amino]­methyl}‐4‐methyl­phenolato)­bis­[di­aqua­nickel(II)] ace­tate dimethyl­formamide 0.75‐hy­drate

The binuclear cation of the title compound, [Ni₂(C₃₃H₂₉­N₄O₃)(H₂O)₄]C₂H₃O₂·C₃H₇NO·0.75H₂O, was synthesized as a model for the active site of urease. Two tridentate halves of the symmetrical 2,6‐bis{[(2‐hydroxy­phenyl)(2‐pyridyl­methyl)­amino]­methyl}‐4‐methyl­phenolate (BPPMP^3?) ligand are arranged in a meridional fashion around the two Ni^II ions, with the phenoxo O atom bridging the Ni^II ions. The cation has an approximate twofold rotation axis running through the C—O bond of the bridging phenolate group. Four water mol­ecules complete the octahedral environment of each Ni^II ion.     

Synthesis and characterization of a new macrocyclic Schiff base derived from 2,6-diaminopyridine and 1,10-bis(2-formylphenyl)-1,4,7,10-tetraoxadecane and its Cu(II), Ni(II), Pb(II), Co(III) and La(III) complexes

A new macrocyclic ligand, 1,3,5-triaza-2,4:7,8:19,20-tribenzo-9,12,15,18-tetraoxacyclounkosa-1,5-diene (L) was synthesized by reaction of 2,6-diaminopyridine and 1,10-bis(2-formylphenyl)-1,4,7,10-tetraoxadecane. Then, its Cu^II, Ni^II, Pb^II, Co^III and La^III complexes were synthesized by the template effect by reaction of 2,6-diaminopyridine and 1,10-bis(2-formylphenyl)-1,4,7,10-tetraoxadecane and Cu(NO₃)₂· 3H₂O, Ni(NO₃)₂· 6H₂O, Pb(NO₃)₂, Co(NO₃)₂· 6H₂O, La(NO₃)₃·6H₂O respectively. The ligand and its metal complexes have been characterized by elemental analysis, IR, ¹H and ¹³C NMR, u.v–vis spectra, magnetic susceptibility, conductivity measurements and mass spectra. All complexes are diamagnetic and the Cu^II complex is binuclear. The Co^III complex was oxidized to Co^III.     

Synthesis of new macrocyclic lactones and their extraction study

New macrocyclic lactones were synthesized by reaction of 3-bromo-5-(5-tert-butyl-2-hydroxybenzyl)biphenyl-4-ol with appropriate polyethylene glycol-based dicarboxylic acid dichlorides, and their complexes with Mg(ClO₄)₂·6H₂O, Pb(SCN)₂, NaClO₄·H₂O, and KClO₄ were prepared. The macrocyclic ligands were evaluated as extractants in the transfer of Li⁺, Na⁺, K⁺, Cu²⁺, Ni²⁺, and Hg²⁺ picrates from aqueous to organic phase. Published in Russian in Zhurnal Organicheskoi Khimii, 2008, Vol. 44, No. 9, pp. 1400–1405. The text was submitted by the authors in English.     

High-yield preparation of rod-like CaSO<Subscript>4</Subscript>/Fe<Superscript>0</Superscript> magnetic composite for effective removal of Cu<Superscript>2+</Superscript> in wastewater

In this study, a simple approach was described for the fabrication of CaSO₄/Fe⁰ composite used as a novel adsorbent for the reductive removal of Cu²⁺ from aqueous solutions. The magnetic CaSO₄/Fe⁰ composite was prepared by a solid state reaction at 550 °C in the H₂ atmosphere using CaSO₄·2H₂O/α-FeOOH as a precursor. The structure and morphology of the as-synthesized magnetic composite were characterized by X-ray diffraction, field emission scanning electron microscopy and a superconducting quantum interference device, respectively. Results showed that the CaSO₄/Fe⁰ composite with a rod-like shape could be easily acquired from the CaSO₄·2H₂O/α-FeOOH precursor with the ratio of 1:0.5 at 550 °C in the H₂ atmosphere for 1 h. The CaSO₄/Fe⁰ composite exhibited enhanced performance relevant to the reductive removal of Cu²⁺. The removal amount of Cu²⁺ increased linearly with increasing of concentration of Cu²⁺ in wastewater. Possible removal mechanisms were proposed as follows: (1) the formation of Cu₂O by fast reduction of Cu²⁺ with Fe⁰ nanoparticles on interface of CaSO₄/Fe⁰ composite, (2) proper adsorption of Cu²⁺ on the surface of CaSO₄/Fe⁰ composite, (3) the hydrous iron oxide (HIO) such as Fe (OH)₃ and FeOOH in situ generated on the rest of CaSO₄/Fe⁰ composite could further adsorb Cu²⁺ from wastewater.     

Controllable synthesis and property of graphene-based magnetic metal nanostructures

A facile and effective solution phase reduction method was developed to synthesize graphene-based magnetic metal nanocomposites. Metals (Co, and Ni) or alloys (Fe₅₁Co₄₉, Fe₄₈Ni₅₂, Ni₄₉Co₅₁, Co₅₁Cu₄₉, and Ni₅₂Cu₄₈)/reduced graphene oxide (RGO) nanocomposites were successfully prepared by reduction of the corresponding aqueous metal ions and ethylenediamine (EDA)–graphene oxide (GO) with hydrazine hydrate at 353 K for 1 h under N₂ atmosphere. The effects of synthetic parameters such as metal ions concentration, adding sequence of NaOH and N₂H₄·H₂O, linkage agent and reaction time on the formation of nanocomposites were investigated. The experimental results showed that using ethylenediamine and adding sequence played critical roles in the formation of metals or alloys/RGO nanocomposites. Magnetic hysteresis measurements revealed that the as-synthesized metals or alloys in nanocomposites showed excellent soft magnetic behavior with enhanced saturation magnetization, and could have promising applications in biotechnology, catalysis, and magnetic storage devices.     

A Homochiral Metal‐Dipeptide Supramolecular Framework Including a Hydrogen‐bonded Guest Network of Water and Uncoordinated 4, 4′‐Bipyridine

Abstract. The self‐assembly of glycyl‐L ‐leucine, Cu(NO₃)₂ · 3H₂O and 4, 4′‐bipyridine resulted in the tetranuclear‐based metal‐dipeptide supramolecular framework [Cu₄(C₈H₁₄N₂O₃)₄(H₂O)₂(C₁₀H₈N₂)₂] · (C₁₀H₈N₂) · 13H₂O ( 1 ). In the structure, the 4, 4′‐bipyridine‐bridged tetranuclear complex of Cu^II‐glycyl‐L ‐leucine interacts with each other to form a 1D hydrogen‐bonded chain including uncoordinated 4, 4′‐bipyridine and an interesting water chain in different channels. Under similar reaction conditions, racemic glycyl‐D ,L ‐leucine gave rise to the centrosymmetric dinuclear complex [Cu₂(C₈H₁₄N₂O₃)₂(C₁₀H₈N₂)] · 2H₂O ( 2 ), which is linked into a 2D hydrogen‐bonded structure without 4, 4′‐bipyridine included.     

Preparation and characterization of mononuclear nickel(II) and copper(II) complexes of a hexaazamacrobicyclic ligand

Summary The structure of the hexaazamacrobicycle, sarcophagine, (diAMMEsar)·2H₂O, formed by extracting Co ion from the [Co(diAMMEsar H₂)]Cl₅·-H₂O cage with 8-hydroxyquinoline, has been determined by elemental analysis, and i.r., u.v.-vis., ¹H-n.m.r. and mass spectroscopies. Two octahedral complexes, [M(diAMM-EsarH₂)]Cl₄·2H₂O (M = Ni^II or Cu^II), have been prepared and characterized. The e.s.r. spectrum of the Cu^II complex in the solid state indicates spin-exchange interaction between the Cu^II ions. However, in CD₃OD-D₂O (10%) at 77K, the spectrum is characteristic of a compound having axial symmetry (d _x ²−y ²).     

3‐(Arylhydrazono)pentane‐2, 4‐diones and their Complexes with Copper(II) and Nickel(II) — Synthesis and Crystal Structures

A series of new 3‐(arylhydrazono)pentane‐2, 4‐diones ( 1 ‐ 6 ) synthesized from pentane‐2, 4‐dione and diazonium salts of respective anilines using the procedure of Japp‐Klingemann are described. Complexes with Cu^II and Ni^II salts are prepared ( 7 ‐ 10 , respectively). Spectroscopic properties of these compounds have been studied and X‐ray crystal structures of selected hydrazones ( 3 , 4 , 6 ) and of the hydrazone complexes ( 7 ‐ 10 ) are reported. The structures of the uncomplexed hydrazones feature an intramolecular N‐H···O interaction to yield a six‐membered H‐bond ring reflecting preference of the hydrazone tautomeric structure. All the complexes are mononuclear 2:1 (L:M) structures of six‐membered chelate type involving N₂O₂ binding sites that are quadratic arranged but differ in the entire coordination environment dependent on the metal and the ligand substitution including distorted octahedral and quadratic pyramidal coordination geometries in the Cu^II complexes 7 and 8 or nearly regular square planar coordination geometry in the Ni^II complexes 9 and 10 , respectively. In the crystal packings, strong and weak H‐bond interactions cause supramolecular network structures.     

Novel mixed-ligand complexes of coumarilate/<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>′-diethylnicotinamide with some transition metals

Coordination complexes of transition metal cations (Co^II, Ni^II, Cu^II and Zn^II) containing coumarilate and N,N′-diethylnicotinamide were synthesized. The structural characterization and thermal behaviour analysis of novel samples synthesized were conducted through elemental analysis, magnetic susceptibility, solid-state UV–Vis, direct and injection probe mass spectra, FTIR spectra, thermoanalytic TG-DTG/DTA and single crystal X-ray diffraction methods. The structural details of single crystals of [Co(dena)₂(H₂O)₄](coum)₂ (I) and [Cu(coum)₂(dena)₂(H₂O)₂] (III) complexes were resolved completely. Moreover, the results of analysis obtained for [Ni(coum)₂(dena)₂(H₂O)₂] (II) and [Zn(dena)₂(H₂O)₄](coum)₂ (IV) complexes were interpreted considering the samples with crystal structures defined and made assumptions about the structural details. It was determined that the complex of Co^II metal cation has salt-type structure and the coordination number of metal is accomplished to six as the sum of 4 mol of water and also 2 mol of N,N′-diethylnicotinamide ligands in trans position located within the coordination sphere. It was observed that 2 mol of coumarilate anions are located outside the coordination sphere and have stabilized to the charge (2+) of metal. The Cu^II complex has totally molecular structure, and the coordination sphere of metal cation was 6 as the sum of 2 mol of water, 2 mol of N,N′-diethylnicotinamide and 2 mol of monoanionic monodentate coumarilate ligands. All ligands have been located in –trans position. The geometry of both complex structures is distorted octahedral. It is assumed that the Ni^II complex structure is isostructural with Cu^II complex structure and also does Zn^II complex with Co^II structure. It was determined that the decomposition products obtained from thermal analysis are the oxides of related metal cations.