Synthesis,spectroscopic, and thermal analyses of trinuclear Mn(II), Co(II), Ni(II), and Zn(II) complexes with some sulfa derivatives

New bi- and trihomonuclear Mn(II), Co(II), Ni(II), and Zn(II) complexes with sulfa-guanidine Schiff bases have been synthesized for potential chemotherapeutic use. The complexes are characterized using elemental and thermal (TGA) analyses, mass spectra (MS), molar conductance, IR, ¹H-NMR, UV-Vis, and electron spin resonance (ESR) spectra as well as magnetic moment measurements. The low molar conductance values denote non-electrolytes. The thermal behavior of these chelates shows that the hydrated complexes lose water of hydration in the first step followed by loss of coordinated water followed immediately by decomposition of the anions and ligands in subsequent steps. IR and ¹H-NMR data reveal that ligands are coordinated to the metal ions by two or three bidentate centers via the enol form of the carbonyl C=O group, enolic sulfonamide S(O)OH, and the nitrogen of azomethine. The UV-Vis and ESR spectra as well as magnetic moment data reveal that formation of octahedral [Mn₂L¹(AcO)₂(H₂O)₆] (1), [Co₂(L¹)₂(H₂O)₈] (2), [Ni₂L¹(AcO)₂(H₂O)₆] (3), [Mn₃L²(AcO)₃(H₂O)₉] (5), [Co₃L²(AcO)₃(H₂O)₉] · 4H₂O (6), [Ni₃L²(AcO)₃(H₂O)₉] · 7H₂O (7), [Mn₃L³(AcO)₃(H₂O)₆] (9), [Co₂(HL³)₂(H₂O)₈] · 4H₂O (10), [Ni₃L³(AcO)₃(H₂O)₉] (11), [Mn₃L⁴(AcO)₃(H₂O)₉] · H₂O (13), [Co₂(HL⁴)₂(H₂O)₈] · 5H₂O (14), and [Ni₃L⁴(AcO)₃(H₂O)₉] (15) while [Zn₂L¹(AcO)₂(H₂O)₂] (4), [Zn₃L²(AcO)₃(H₂O)₃] · 2H₂O (8), [Zn₃L³(AcO)₃(H₂O)₃] · 3H₂O (12), and [Zn₃L⁴(AcO)₃(H₂O)₃] · 2H₂O (16) are tetrahedral. The electron spray ionization (ESI) MS of the complexes showed isotope ion peaks of [M]⁺ and fragments supporting the formulation.     

Ten complexes constructed by two reduced Schiff base tetraazamacrocycle ligands: syntheses,structures, magnetic and luminescent properties

Ten new complexes, [Cu₂(L¹)(NO₃)₂]·2H₂O (1), [Cu₄(L¹)₂]·4ClO₄·H₂O (2), [Cu₂(L¹)(H₂O)₂]·(adipate) (3), [Cu₆(L¹)₂(m-bdc)₄]·2DMF·5H₂O (4), [Cu₂(L¹)(Hbtc)]·5H₂O (5), [Cu₂(L¹)(H₂O)₂]·(ntc)·3H₂O (6), [Co₂(L²)]·[Co(MeOH)₄(H₂O)₂] (7), [Co₃(L²)(EtOH)(H₂O)] (8), [Ni₆(L²)₂(H₂O)₄]·H₂O (9) and [Zn₄(L²)(OAc)₂]·0.5H₂O (10), have been synthesized. 1 displays a [Cu₂(L¹)(NO₃)₂] monomolecular structure. 2 shows a supramolecular chain including [Cu₂L¹]²⁺. In 3, two Cu(II) ions are connected by L¹ to form a [Cu₂(L¹)(H₂O)₂]²⁺ cation. In 4, the m-bdc anions bridge Cu(II) ions and L¹ anions to form a layer. Both 5 and 6 display 3-D supramolecular structures. 7 consists of both [Co₂L²]^2? and [Co(MeOH)₄(H₂O)₂]²⁺ units. 8 and 9 show infinite chain structures. In 10, Zn(II) dimers are linked by L² to generate a 3-D framework. The magnetic properties for 4 and 8 and the luminescent property for 10 have been studied.     

Synthesis,structures, catalytic,and anticancer activities of some coordination compounds involving two new triazole derivatives

Five N-heterocyclic carboxylate-based coordination complexes, [Co(L¹)₂(H₂O)₂]·2H₂O (1), [Cd(L¹)₂(H₂O)₂]·2H₂O (2), [Co(L²)(H₂O)₃] (3), [Ni(L²)(H₂O)₃] (4), and [Cu₂(L²)₂(H₂O)₂] (5), have been synthesized and characterized by elemental analysis, IR spectroscopy, Powder X-ray diffraction, thermogravimetric analyses, and single-crystal X-ray crystallography, where HL¹ is 2-((5-amino-1H-1,2,4-triazol-3-yl)thio)acetic acid and H₂L² is 2-((5-amino-1-(carboxymethyl)-1H-1,2,4-triazol-3-yl)thio)acetic acid. In these complexes, the hydrogen bonds (H-bonds) play an important role in their packing structures. Complex 1 has nine H-bonds showing a 3-D sqc38 topology. Complex 2 has 17 H-bonds exhibiting a 3-D hxl network. Complexes 3 and 4 are isomorphic, both of which possess ten H-bonds to present a 3-D btc topology. Complex 5 with eight H-bonds forms a 2-D sq1 structure. In addition, complex 3 catalyzes the decolorization of methyl orange. Meanwhile, 1, 3, and 5 show certain anticancer activities to inhibit the growth of HepG2 cells.     

Syntheses,crystal structures,and magnetic properties of 1-D coordination polymers

Three coordination polymers of Robson-type macrocycles, {[Cu₄L¹(4,4′-bipy)₂]·4ClO₄·H₂O}_∞ (1), {[Cu₄L²(4,4′-bipy)₄]·2CH₃CN·4ClO₄·2H₂O}_∞ (2), and {[Zn₂L²(4,4′-bipy)₂]·(ClO₄)₂}_∞ (3) (where H₂L¹ and H₂L² are the [2?+?2] condensation products of 1,3-diaminopropane with 2,6-diformyl-4-methylphenol and 2,6-diformyl-4-fluorophenol, respectively), have been synthesized and characterized. Magnetic susceptibility was measured for 1 and 2 from 2 to 300?K. The optimized magnetic data were J?=?–368.5?cm^?1, J′?=?40.5?cm^?1 with R?=?1.69?×?10^?6 for 1 and J?=?–291.22?cm^?1, J′?=?83.74?cm^?1, ρ = 0.00168 with R?=?1.8?×?10^?11 for 2, respectively. The data reveal strong antiferromagnetic interactions between two Cu(II) ions in the macrocyclic unit and ferromagnetic interaction between the Cu(II) ions in two adjacent macrocyclic units for 1 and 2.     

Synthesis,Structural Characterization,and Antimicrobial Activities of Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) Complexes of Triazole‐based Azodyes

The synthesis and characterization of new transition metal complexes of Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) with 3‐(2‐hydroxynaph‐1‐ylazo)‐1,2,4‐triazole ( HL¹ ) and 3‐(2‐hydroxy‐3‐carboxynaph‐1‐ylazo)‐1,2,4‐triazole ( HL² ) have been carried out. Their structures were confirmed by elemental analyses, thermal analyses, spectral and magnetic data. The IR and ¹H NMR spectra indicated that HL¹ and HL² coordinated to the metal ions as bidentate monobasic ligands via the hydroxyl O and azo N atoms. The UV‐Vis, ESR spectra and magnetic moment data revealed the formation of octahedral complexes [Mn L¹ (AcO)(H₂O)₃] ( 1 ), [Co L¹ (AcO)(H₂O)₃]·H₂O ( 2 ), [Mn L² (AcO)(H₂O)₃] ( 6 ) and [Co L² (AcO)(H₂O)₃] ( 7 ), [Ni L¹ (AcO)(H₂O)] ( 3 ), [Zn L¹ (AcO)(H₂O)]·H₂O ( 5 ), [Ni L² (AcO)(H₂O)] ( 8 ), [Zn L² (AcO)(H₂O)]·10H₂O ( 10 ) have tetrahedral geometry, whereas [Cu L¹ (AcO)(H₂O)₂] ( 4 ) and [Cu L² (AcO)(H₂O)₂]·5H₂O ( 9 ) have square pyramidal geometry.. The mass spectra of the complexes under EI‐con‐ ditions showed the highest peaks corresponding to their molecular weights, based on the atomic weights of ⁵⁵Mn, ⁵⁹Co, ⁵⁸Ni, ⁶³Cu and ⁶⁴Zn isotopes; besides, other peaks containing other isotopes distribution of the metal. Kinetic and thermodynamic parameters of the thermal decomposition stages were computed from the thermal data using Coats‐Redfern method. HL² and complexes 6 – 10 were found to have moderate antimicrobial activities against Staphylococcus aureus (gram positive), Escherichia coli (gram negative) and Salmonella sp bacteria, and antifungal activity against Fusarium oxysporum, Aspergillus niger and Candida albicans. Also, in most cases, metallation increased the activity compared with the free ligand.     

Macrocyclic effects upon isomeric CuIIMII and MIICuII cores. Formation with unsymmetric phenol-based macrocyclic ligands

This paper discusses coordination-position isomeric M^IICu^II and Cu^IIM^II complexes, using unsymmetric dinucleating macrocycles (L^m;n)²⁻ ((L^2;2)²⁻, (L^2;3)²⁻ and (L^2;4)²⁻) that comprise two 2-(N-methyl)-aminomethyl-6-iminomethyl-4-bromo-phenonate entities, combined through the ethylene chain (m = 2) between the two amine nitrogens and through the ethylene, trimethylene or tetramethylene chain(n = 2, 3 or 4) between the two imine nitrogens. The macrocycles have dissimilar N(amine)₂O₂ and N(imine)₂O₂ metal-binding sites sharing the phenolic oxygens. The reaction of the mononuclear Cu^II precursors, [Cu(L^2;2)], [Cu(L^2;2)] and [Cu(L^2;2)], with a M^II perchlorate and a M^II acetate salt formed (acetato)M^IICu^II complexes: [CoCu(L^2;2)(AcO)]ClO⁴·0.5H₂O] (1), [NiCu(L^2;2) (AcO)]ClO₄ (2), [ZnCu(L^2;2) (AcO)]ClO₄ (3), [CoCu(L^2;3)(AcO)]ClO₄·0.5H₂O (4), [NiCu(L^2;3)(AcO)]ClO₄ (5), [ZnCu(L^2;3)(AcO)]ClO₄·0.5H₂O (6), [CoCu(L^2;4)(AcO)(DMF)]ClO₄ (7), [NiCu(L^2;4) (AcO)]ClO₄·2DMF (8) and [ZnCu(L^2;4)(AcO)]ClO₄ (9) (the formulation [M_aM_b (L^m;n)]²⁺ means that M_a resides in the aminic site and M_b in the iminic site). The site selectivity of the metal ions is demonstrated by X-ray crystallographic studies for 2·MeOH,3,5,7, and9. An (acetato)Cu^IIZn^II complex, [CuZn(L^2;3)(AcO)]ClO₄ (10), was obtained by the reaction of [PbCu(L^2;3)]-(ClO₄)₂ with ZnSO₄·4H₂O, in the presence of sodium acetate. Other complexes of the Cu^IIM^II type were thermodynamically unstable to cause a scrambling of metal ions. The Cu migration from the iminic site to the aminic site in the synthesis of10 is explained by the ‘kinetic macrocyclic effect’. The coordination-position isomers,6 and10, are differentiated by physicochemical properties.     

Three 2-(4-thiazolyl)benzimidazole-based supramolecular assemblies oriented by Keggin and Wells–Dawson anions

Three polyoxometalate supramolecular assemblies based on rigid 2-(4-thiazolyl)benzimidazole (L) and two types of polytungstate anions, [Cu^II₂Cl(L)₄(PW₁₂O₄₀)]·3H₂O (1), [Cu^II(L)₂(H₂O)]₂[P₂W₁₈O₆₂]·(HL)₂·6H₂O (2), and [Zn^II(L)₃]₄[H(KPW₁₂O₄₀)₃] (3), have been synthesized and characterized by single-crystal X-ray diffraction, elemental analyses, and IR spectra. Compound 1 contains binuclear copper clusters {Cu₂L₄Cl}³⁺ with Cl^– as bridges. These binuclear clusters and [PW₁₂O₄₀]^3– anions construct a supramolecular 2-D layer through hydrogen-bonding interactions. In 2, the [CuL₂(H₂O)]²⁺ subunits and Wells–Dawson anions build a 1-D supramolecular chain. In 3, the [PW₁₂O₄₀]^3– anions are covalently linked by K⁺ to form an inorganic chain. These chains and discrete [Zn^II(L)₃]²⁺ subunits construct a 3-D supramolecular structure. The electrochemical and photocatalytic properties of 1–3 have been studied.     

Synthesis and characterization of CuII and CoII complexes derived from 2,4,6-tri-(2-pyridyl)-1,3,5-triazine (TPT) by chemical and tribochemical reactions

Four Cu^II and Co^II complexes–[Cu(L₁)Cl₂(H₂O)]3/2H₂O · 1/2EtOH, [Cu(L₁)₂Cl₂]6H₂O, [Co(L₁)Cl₂]3H₂O · EtOH, and [Co₂(L₁)(H₂O)Cl₄]1.5H₂O · EtOH (L₁ = 2,4,6-tri(2-pyridyl)-1,3,5-triazine; TPT)–were synthesized by conventional chemical method and used to synthesize another four metal complexes–[Cu(L₁)I₂(H₂O)]6H₂O, [Cu(L₁)₂I₂]6H₂O, [Co(L₁)I(H₂O)₂]I · 2H₂O, and [Co₂(L₁)I₄(H₂O)₃]–using tribochemical reaction, by grinding it with KI. Substitution of chloride by iodide occurred, but no reduction for Cu^II or oxidation of Co^II. Oxidation of Co^II to Co^III complexes was only observed on the dissolution of Co^II complexes in d₆-DMSO in air while warming. The isolated solid complexes (Cu^II and Co^II) have been characterized by elemental analyses, conductivities, spectral (IR, UV-Vis, ¹H-NMR), thermal measurements (TGA), and magnetic measurements. The values of molar conductivities suggest non-electrolytes in DMF. The metal complexes are paramagnetic. IR spectra indicate that TPT is tridentate coordinating via the two pyridyl nitrogens and one triazine nitrogen forming two five-membered rings around the metal in M : L complexes and bidentate via one triazine nitrogen and one pyridyl nitrogen in ML₂ complexes. In binuclear complexes, L is tridentate toward one Co^II and bidentate toward the second Co^II in [Co₂(L₁)Cl₄]2.5H₂O · EtOH and [Co₂(L₁)I₄(H₂O)₃]. Electronic spectra and magnetic measurements suggest a distorted-octahedral around Cu^II and high-spin octahedral and square-pyramidal geometry around Co^II.     

Cobalt(II) complexes with pyridine and 5-[(E)-2-(aryl)-1-diazenyl]-quinolin-8-olates: synthesis,electrochemistry and X-ray structural characterization

Abstract

Nine new cobalt(II) compounds, trans-[Co(L^PAQ)₂(Py)₂] (1), trans-[Co(L^PAQ)₂(3-MePy)₂] (2), trans-[Co(L^MeAQ)₂(Py)₂] (3), trans-[Co(L^OMeAQ)₂(Py)₂] (4), trans-[Co(L^OEtAQ)₂(Py)₂]·2(H₂O) (5), trans-[Co(L^CAQ)₂(Py)₂] (6), trans-[Co(L^BAQ)₂(Py)₂] (7), cis-[Co(L^BAQ)₂(3-MePy)₂] (8a) and trans-[Co(L^BAQ)₂(3-MePy)₂]·2(3-MePy) (8b) (primary ligand: L^XAQ?=?substituted 5-[(E)-2-(aryl)-1-diazenyl]quinolin-8-olate; secondary ligands: Py?=?pyridine, 3-MePy = 3-methylpyridine), have been synthesized and characterized by elemental analysis, IR and UV-vis spectroscopy. Magnetic measurements of the cobalt compounds were performed in solution by ¹H NMR spectroscopy using the Evans’ method while their redox properties were studied by cyclic voltammetry. Single-crystal X-ray diffraction analysis of the compounds revealed their octahedral geometries and trans configuration, except for 8a, which has a cis configuration. Intermolecular noncovalent interactions were detected, π···π interactions in 5, C?–?H···π interactions in 2 and C?–?H···π edge-to-face (T-shaped) arrangements in 3, 4, 6, and 7.     

Synthesis,structures, and urease inhibition of nickel(II), zinc(II), and cobalt(II) complexes with similar hydroxy-rich Schiff bases

Four new nickel(II), zinc(II), and cobalt(II) complexes, [Zn(L¹)₂]?·?H₂O (1), [Ni(L¹)₂]?·?H₂O (2), [Ni(L²)₂] (3), and [Co(L³)₂]?·?H₂O (4), derived from hydroxy-rich Schiff bases 2-{[1-(5-chloro-2-hydroxyphenyl)methylidene]amino}-2-methylpropane-1,3-diol (HL¹), 2-{[1-(2-hydroxy-3-methoxyphenyl)methylidene]amino}-2-ethylpropane-1,3-diol (HL²), and 2-{[1-(5-bromo-2-hydroxyphenyl)methylidene]amino}-2-methylpropane-1,3-diol (HL³) have been synthesized and characterized by elemental analyses, infrared spectroscopy, and single-crystal X-ray determination. Each metal in the complexes is six-coordinate in a distorted octahedral coordination. The Schiff bases coordinate to the metal atoms through the imino N, phenolate O, and one hydroxyl O. In the crystal structures of HL¹ and the complexes, molecules are linked through intermolecular O–H···O hydrogen bonds, forming 1-D chains. The urease inhibitory activities of the compounds were evaluated and molecular docking study of the compounds with the Helicobacter pylori urease was performed.     

Thermal behaviour of new Cu(II) complexes with Schiff bases functionalised with 1,3,5-triazine moieties as potential antibacterial agents

New complexes of type [Cu(L¹)₂(OH₂)]·4H₂O (1), [Cu(L²)(OH₂)]·0.5H₂O (2) and [Cu₃(L³)₂(OH₂)₃]·0.5H₂O (3) were synthesized by [1 + 1], [1 + 2] and [1 + 3], respectively, template condensation of 2,4,6-triamino-1,3,5-triazine and salicylic aldehyde in the presence of copper(II). The features of complexes have been established from microanalytical, IR and UV–Vis data. The thermal analyses have evidenced the thermal intervals of stability and also the accompanying thermodynamic effects. Processes as water elimination and oxidative degradation of the organic ligands were observed. After water elimination, complexes revealed a similar thermal behaviour. The final product of decomposition was copper(II) oxide as powder X-ray diffraction indicated.     

Synthesis,crystal structure,and fluorescence of an unexpected dialkoxo-bridged dinuclear copper(II) complex with bis(salen)-type tetraoxime

An unexpected dinuclear Cu(II) complex, [Cu₂(L²)₂] (H₂L^2?=?3-methoxysalicylaldehyde O-(2-hydroxyethyl)oxime), has been synthesized via complexation of Cu(II) acetate monohydrate with H₄L¹. Catalysis by Cu(II) results in unexpected cleavage of two N–O bonds in H₄L¹, giving a dialkoxo-bridged dinuclear Cu(II) complex possessing a Cu–O–Cu–O four-membered ring core instead of the usual bis(salen)-type tetraoxime Cu₃–N₄O₄ complex. Every complex links six other molecules into an infinite-layered supramolecular structure via 12 intermolecular C–H?···?O hydrogen bonds. Furthermore, Cu(II) complex exhibits purple emission with maximum emission wavelength λ_max?=?417?nm when excited with 312?nm.     

Synthesis, crystal structures, and magnetic properties of tetranuclear nickel(II) and copper(II) complexes with tridentate Schiff bases

Two cubane-type tetranuclear nickel(II) and copper(II) complexes, [Ni₄(L¹)₄(CH₃OH)₄] (1) and [Cu₄(L²)₄]·H₂O (2), where L¹ and L² are the dianionic forms of the tridentate Schiff bases 4-nitro-2-[(2-hydroxyethylimino)methyl]phenol (H₂L¹) and 5-methoxy-2-[(2-hydroxyethylimino)methyl]phenol (H₂L²), respectively, have been synthesized and characterized by physicochemical methods and single-crystal X-ray diffraction. The magnetic properties of the complexes show the presence of ferromagnetic interactions for complex 1 and antiferromagnetic interactions for complex 2, mediated by hydroxyl bridges.     

Structural diversity of a series of urea-based coordination complexes: from water tapes,water-sulfate chains,to supramolecular structures

[Hg₂(L₁)₂I₄] (1), [Cd₂(L₁)₂I₄] (2), {[Cd(L₁)₂(SO₄)(H₂O)]·4H₂O}_n (3), {[Zn₂(L₂)₂(Cl)₄]·0.5H₂O} (4), {[Cu₂(L₂)₂(SO₄)₂(H₂O)₄]·2.5H₂O} (5), and {[Cd(L₂)₂(SO₄)(H₂O)]·3H₂O}_n (6), based on N–(3–picolyl)–N′–(3–pyridyl)urea (L₁) or N–(4–picolyl)–N′–(3–pyridyl)urea (L₂), have been synthesized and characterized by elemental analyses, IR spectra, single-crystal and powder X-ray diffraction, and thermogravimetric analyses. Complexes 1 and 2 are isomorphous and feature similar rectangular metal organic loops, which were further extended into 2-D supramolecular structures through hydrogen bonds. Complex 3 possesses a 2-D sql sheet, and the channels between the neighboring sheets are filled with lattice water molecules, which formed a 1-D water tape. Complex 4 also exhibits a rectangular metal organic loop and a 3-D supramolecular structure with the help of hydrogen bonding interactions. Complex 5 also possesses a metal organic loop, and the water molecules interacted with sulfates, constructing a 1-D water–sulfate tube. Complex 6 features a 1-D loop polymeric chain. Moreover, the solid state luminescences of 1–4 and 6 have been investigated.     

Dinuclear copper(II) complexes of Fenoprofen: synthesis,spectroscopic, thermal,and SOD-mimic activity studies

Three dinuclear copper(II) complexes with the anti-inflammatory drug Fenoprofen [Hfen, 2-(3-phenoxyphenyl)propionic acid] and nitrogen donors of general formula [Cu₂(fen)₄(L)] _n were prepared from [Cu₂(fen)₄(dmf)₂]·2H₂O (1) [dmf?=?N,N′-dimethylformamide; L?=?4,4′-bipyridine (2), pyrazine (3), and 2,5-dimethylpyrazine (4)]. The new complexes were characterized by chemical analysis, spectroscopic, and thermogravimetric techniques. Antioxidant properties of 1–4 were evaluated for superoxide-dismutase-mimic activity employing the XTT method. Complex 2 presented the highest antioxidant activity (IC₅₀?=?0.260?µmol?L^?1). Anti-inflammatory properties of 2 were evaluated employing carrageenan-induced paw edema in mice, revealing that the Fenoprofen–copper(II) complex containing 4,4′-bipyridine does not present enhanced anti-inflammatory activity compared to the uncomplexed parent drug Fenoprofen calcium salt.     

Cyano-bridged heterometallic complexes directed by binuclear copper units

A tridentate N,O-donor, 1,3-bis(3,5-dimethylpyrazol-1-yl)propan-2-ol (HL), has been employed to synthesize cyano-bridged complexes and six heterometallic complexes with [Cu₂L₂] or [Cu₂L₂(H₂O)] have been generated by using slow diffusion. With slightly different synthetic conditions, subtle variations in the crystal structures of the complexes occur. [Cu₂L₂][Fe(CN)₅NO]?2CH₃CN (1) and [Cu₂L₂][Fe(CN)₅NO]?H₂O (2), synthesized in different solvents with the same precursor, exhibit a very similar 1-D zig-zag chain motif in different space groups, P2₁ and P-1, respectively. Similarly, [Cu₂L₂(H₂O)][Ni(CN)₄]·H₂O (3) and [Cu₂L₂][Ni(CN)₄]?H₂O (4), synthesized with different diffusion methods, feature trinuclear and 1-D zig-zag chain structures, which indicates a solvent effect of water. [Cu₂L₂(H₂O)]₂[Cu₂L₂][W(CN)₈]₂·8H₂O (5) is composed of two [W(CN)₈]^3? and three [Cu₂L₂]²⁺ units. In the octanuclear structure, [W(CN)₈]^3? and one [Cu₂L₂]²⁺ bridge and the other two [Cu₂L₂]²⁺ are terminal to stop extending the 1-D structure. [CuL][Ag_2.24Cu_0.76(CN)₄] (6) exhibits a discrete structure, in which the complex anion forms a unique 2-D 6³ network and the complex cations are inserted in the space between two adjacent networks. Magnetic properties of 1 and 4 are discussed.     

Syntheses and crystal structures of phthalato-, succinato-, maleato-, acetylenedicarboxylato-bridged [bis(2-pyridylcarbonyl)amide]copper(II) complexes

Self-assemblies of the 2,4,6-tris(2-pyridyl)-1,3,5-triazine (tptz) and Cu(OH)₂ in the presence of dicarboxylate ligands yielded four new complexes, [Cu₄(bpca)₄(L1)₂(H₂O)₂]·5H₂O (1), [Cu₂(bpca)₂(L2)(H₂O)₂]·2H₂O (2), [Cu₂(bpca)₂(L3)(H₂O)₂]·H₂O (3), and [Cu₂(bpca)₂(L4)(H₂O)₂]·3H₂O (4) (bpca = bis(2-pyridylcarbonyl)amide anion, H₂L1 = phthalic acid, H₂L2 = succinic acid, H₂L3 = maleic acid, H₂L4 = acetylenedicarboxylic acid). Their structures were determined by single-crystal X-ray diffraction analyzes and further characterized by IR spectra and thermogravimetric analyzes. The five-coordinate Cu ions in 1 are bridged by phthalate to form 1-D chains, which are assembled into 3-D frameworks by extensive hydrogen bonds. Compounds 2–4 possess similar structures, built up of [Cu₂(bpca)₂(L)(H₂O)₂] (L = L2 for 2, L3 for 3, L4 for 4) and lattice molecules. The 3-D frameworks of 2–4 are completed by hydrogen bond interactions.     

Synthesis, structural characterization and thermal properties of three copper(II) complexes based on aryl hydrazide ligands

The thiosemicarbazide and hydrazide Cu(II) complexes, [Cu₃L₂¹(py)₄Cl₂] (1), [Cu(HL²)py] (2) and [Cu(HL³)py] (3), (H₂L¹ = 1-picolinoylthiosemicarbazide, H₃L² = N′-(2-hydroxybenzylidene)-3-hydroxy-2-naphthohydrazide, H₃L³ = 2-hydroxy-N′-((2-hydroxy-naphthalen-1-yl)methylene)benzohydrazide) have been prepared and characterized through physicochemical and spectroscopic methods as well as X-ray crystallography. Complex 1 has a centrosymmetric structure with –N–N– bridged Cu₃ skeleton. Neighboring molecules are linked into a 3D supermolecular framework by π–π stacking interactions, N–H···Cl and C–H···Cl hydrogen bonds. Complexes 2 and 3 have similar planar structures but different dimers formed by concomitant Cu···N and Cu···O interactions, respectively. Solvent accessible voids with a volume of 391 ?³ are included in the structure of complex 2, indicating that this complex is a potential host candidate. Thermogravimetric analysis shows that the three complexes are stable up to 100 °C.     

Coordination compounds of cobalt(II), nickel(II), and copper(II) with 4-(3-hydroxyphenyl)-1,2,4-triazole: Synthesis and study

New Co(II), Ni(II), and Cu(II) complexes with 4-(3-hydroxyphenyl)-1,2,4-triazole (L) with the compositions [Co₃L₆(H₂O)₅(C₂H₅OH)](NO₃)₆ · 2H₂O · C₂H₅OH (I), [Ni₃L₆(H₂O)₆](NO₃)₆ · 2H₂O (II), and [M₃L₆(H₂O)₆](ClO₄)₆ · nH₂O (M = Co2⁺, n = 2 (III); Ni²⁺, n = 2 (IV); Cu²⁺, n = 0 (V)) are synthesized. The complexes are studied by X-ray structure analysis, X-ray diffraction analysis, UV and IR spectroscopy, and the statistical magnetic susceptibility method. All compounds have the linear trinuclear structure. Ligand L is coordinated to the metal ions by the N(1) and N(2) atoms of the heterocycle according to the bidentate bridging mode. In all compounds the coordination polyhedron of the metal atom is a distorted octahedron. The molecular and crystal structures of compound I, [Co₃L₆(H₂O)₆](ClO₄)₆ · 8C₂H₅OH (IIIa), and [Ni₃L₆(H₂O)₆](ClO₄)₆ · 8C₂H₅OH (IVa) are determined.     

吡唑衍生物的铜和银配合物的合成、结构及光谱研究

在有机溶剂中,我们设计合成了4种配合物:[Cu2Cl4pz*2](1),[Cu2Cl4(L2)2](2),[CuCl(L2)2H2O]Cl.H2O(3),[Ag(L3)2]NO3(4)(pz*=3,5-二甲基吡唑;L2=二吡唑甲烷;L3=4-碘-3,5-二甲基吡唑)。通过元素分析、红外光谱、紫外光谱、X-ray粉末和X-ray单晶衍射方法对其结构进行了表征,分析了其光谱及结构特征。结构分析表明,吡唑烷均采取二齿配位模式,配合物1、3和4中金属的配位数分别为五、六和二;配合物2中则存在2种不同配位模式的中心铜离子。并用Gaussian03量子化学程序包,采用密度泛函理论(DFT)中的B3LYP方法,研究了3个铜配合物的稳定性和电荷分布。