Synthesis,characterization and crystal structures of copper(II), zinc(II) and vanadium(V) complexes,derived from 3-methyl-N′-(1-(pyridin-2-yl)ethylidene)benzohydrazide,with antibacterial activity

Three copper(II), zinc(II), and vanadium(V) complexes, [CuL(HL)]ClO₄ (1), [ZnL₂] (2) and [VO₂L] (3), where L is the anionic form of 3-methyl-N′-(1-(pyridin-2-yl)ethylidene)benzohydrazide (HL), were prepared and characterized by IR, UV–vis and single-crystal X-ray determination. X-ray analysis indicates that the complexes are mononuclear species, with the Cu and Zn ions in 1 and 2 in octahedral coordination, and with the V ion in 3 in trigonal bipyramidal coordination. The hydrazone compound and the three complexes were evaluated for antibacterial activities. The copper complex has effective activities.     

Synthesis,crystal structure and DFT calculations of octahedral nickel(II) complexes derived from N′-[(E)-phenyl(pyridin-2-yl)methylidene]benzohydrazide

The two new nickel(II) complexes, [Ni(HL)(L)](NO₃)?H₂O (1) and [Ni(L)₂] (2) (where HL/L = N′-[(E)-phenyl(pyridin-2-yl)methylidene]benzohydrazide), have been synthesized and characterized by elemental analysis, spectroscopic, magnetic susceptibility, and cyclic voltammetric measurements. Single-crystal X-ray analysis of [Ni(HL)(L)](NO₃)?H₂O (1) and [Ni(L)₂] (2) has revealed the presence of a distorted octahedral geometry around nickel(II). The X-ray and spectral characterizations have confirmed the existence of the keto-enol form of the ligands in the complexes. The electronic structures and spectral properties of the ligands and the complexes have been explained by DFT and TDDFT calculations. Superoxide dismutase activity of these complexes has also been measured.     

Syntheses,crystal structures,and Jack bean urease inhibitory activities of copper(II) complexes derived from 4-tert-butyl-N′-(1-(pyridin-2-yl)ethylidene)benzohydrazide

Two new copper(II) complexes, [CuL(HL)]·ClO₄ (1) and [Cu₂Br₂L₂]·0.85H₂O (2), where L is the monoanionic form of 4-tert-butyl-N′-(1-(pyridin-2-yl)ethylidene)benzohydrazide (HL), have been prepared. The complexes were characterized by infrared and UV–vis spectra, and single crystal X-ray diffraction. Complex 1 is a mononuclear copper(II) species and 2 is a bromido-bridged dinuclear copper(II) species. The Cu ion in 1 is in an octahedral coordination mode and that in 2 is trigonal-bipyramidal. The Jack bean urease inhibitory assay indicated that 2 is active, with IC₅₀ value of 20.6 ± 2.3 μmol L^?1, while 1 is inactive. Molecular docking of 2 with Jack bean urease was studied.     

Syntheses,crystal structures,and fluorescence of two complexes constructed by N ′-(pyridin-2-ylmethylene)-2-( 1H -1,2,4-triazol-1-yl)acetohydrazide

Two new binuclear complexes, Cd₂(HL)₂(NO₃)₄?·?(CH₃OH)₂ (1) and Cu₂(L)₂(ClO₄)₂ (2), based on N′-(pyridin-2-ylmethylene)-2-(1H-1,2,4-triazol-1-yl)acetohydrazide (HL) and Cd(II) and Cu(II) salts have been synthesized and characterized by single crystal X-ray diffraction. Hydrogen bonds and π–π interactions extend both binuclear molecules, a 3-D supramolecular framework for 1 and 1-D staggered chains for 2. Fluorescence of both complexes is discussed.     

A series of multidimensional MOFs incorporating a new N-heterocyclic building block: 5,5′-Di(pyridin-3-yl)-3,3′-bi(1,2,4-triazole)

Using the N-heterocyclic building block 5,5′-di(pyridin-3-yl)-3,3′-bi(1,2,4-triazole) (3,3′-H₂dbpt), four 3-D coordination polymers with diverse connectivity, [M(3,3′-dbpt)]_n, M=Co (1), M=Ni (2), M=Zn (3), and [Cd₂(3,3′-dbpt)Cl₂]_n (4), were constructed. By changing the central metal ions, 3,3′-H₂dbpt had three different coordination modes. Consequently, 1–3, which are isostructural, have a 3-D 4-connected topology with (4².8⁴) Schläfli symbol. 4 has a 3-D (4, 6)-topology, with (4³.6³)₂(4⁶.6⁶.8³) Schläfli symbol. Both 1 and 2 reveal weak antiferromagnetic behavior. In addition, 3 and 4 exhibit purple and blue emission bands, respectively. These results indicate that 3,3′-H₂dbpt is an excellent multi-connection linker to construct MOFs with interesting structures and properties.     

Synthesis and crystal structures of two zinc(II) complexes derived from N-isopropyl-N′-[1-(2-methoxyphenyl)methylidene]ethane-1,2-diamine

Two isostructural mononuclear zinc(II) complexes, [ZnLBr₂] (I) and [ZnLI₂] (II), derived from the Schiff base N-isopropyl-N′-[1-(2-methoxyphenyl)methylidene]ethane-1,2-diamine (L), have been synthesized and characterized by elemental analysis, IR spectra, and X-ray single-crystal diffraction. The crystal of I is monoclinic: space group P2₁/n, a = 14.476(1) Å, b = 7.327(1) Å, c = 17.528(1) Å, β = 101.153(1)°, V = 1824.0(3) ų, Z = 4. The crystal of II is monoclinic: space group P2₁/n, a = 14.482(1), b = 7.329(1), c = 17.528(1)Å, β = 101.195(2)°, V = 1825.0(3)ų, Z = 4. The Zn atom in each complex is four-coordinated in a tetrahedral coordination, with one imine N and one amine N atoms of L, and two halide atoms. Both complexes and the Schiff base were tested in vitro for their antibacterial activities.     

Synthesis,structures, and insulin-like activity of oxidovanadium(V) complexes derived from 2-chloro-N′-(3-ethoxy-2-hydroxybenzylidene)benzohydrazide

Three new oxidovanadium(V) complexes, [VOLL′] (L = 2-chloro-N′-(3-ethoxy-2hydroxybenzylidene)benzohydrazide, L′ = acetohydroxamate for 1, methylmaltolate for 2, and ethylmaltolate for 3), have been prepared. The complexes have been characterized by physicochemical methods and single-crystal X-ray determination. Vanadium in each complex is coordinated by the NOO donor set of L, the OO donor set of L′, and one oxido, forming octahedral coordination. The complexes were administered intragastrically to both normal and alloxan-diabetic mice for two weeks. The biological activities show that the complexes at doses of 10.0 and 20.0 mg V·kg^?1 can significantly decrease the blood glucose level in alloxan-diabetic mice, but the blood glucose level in the treated normal mice was not altered.     

Synthesis,crystal structures and photoluminescence of three new Mn(II) coordination polymers assembled from 2,4′-diphenic acid

Three new metal coordination polymers, [Mn(Hdpa)₂(4,4′-bipy)₂] _n (1), [Mn(dpa)(1,10-phen)(H₂O)] _n (2), and [Mn(dpa)(2,2′-bipy)] _n (3) (H₂dpa = 2,4′-biphenyl-dicarboxylic acid, 4,4′-bipy = 4,4′-bipyridine, 1,10-phen = 1,10-phenanthroline, and 2,2′-bipy = 2,2′-bipyridine), have been synthesized and characterized by elemental analysis, IR, and X-ray diffraction. Single-crystal X-ray analyses reveal that 2,4′-diphenic acid is a bridging ligand, exhibiting three coordination modes to link metal ions: μ ₁-η ¹: η ¹/μ ₀-η ⁰: η ⁰; μ ₂-η ²: η ⁰/μ ₁-η ¹: η ⁰; and μ ₂-η ¹: η ¹/μ ₂-η ¹: η ¹. Intermolecular hydrogen bonds in 1 lead to a zigzag chain. In 2, the 2-D supramolecular arrays extended along b-axis through π–π interactions between 1,10-phen. The dinuclear paddle-wheel second building units (SBUs) constructed by four dpa^2? ligands in 3 are linked by dpa^2? into double-strand chains. The fluorescence of H₂dpa and 1–3 are also determined.     

Syntheses,Structures and Characterizations of Two New Zinc(Ⅱ) Coordination Polymers Constructed from 3-(1H-Pyrazol-4-yl)-5-(pyridin-2-yl)-1,2,4-triazole and Different Carboxylate Ligands

Two new zinc(Ⅱ) coordination polymers, [Zn(ph)(H2 L)·H_2O]2 n(1) and [Zn(ip)(H2 L)-(H_2O)]n(2)(H2 ph = phthalic acid, H2 ip = isophthalic acid, H2L = 3-(1 H-pyrazol-4-yl)-5-(pyridin-2-yl)-1,2,4-triazole), have been successfully synthesized via hydrothermal reaction. It has been structurally characterized by X-ray single-crystal analysis, IR spectra, fluorescence spectroscopy and thermogravimetry analysis. The single-crystal X-ray diffraction studies reveal that compounds 1 and 2 both exhibit 1D chain structures, and assemble into 2D and 3D supermolecules through hydrogen bonds or π-π interactions. Moreover, the thermal stability and luminescent properties of compounds 1 and 2 were also studied.     

Synthesis and crystal structures of cobalt(III), copper(II), nickel(II) and zinc(II) complexes derived from 4-methoxy-N′-(pyridin-2-ylmethylene)benzohydrazide with urease inhibitory activity

Abstract

Urease catalyzes the decomposition of urea into ammonia, which has harmful effects on both human health and fertile soil. Aiming at exploring novel urease inhibitors, a series of hydrazone compounds and their Co^III, Cu^II, Ni^II, and Zn^II complexes were prepared from 4-methoxy-N'-(pyridin-2-ylmethylene)benzohydrazide (HL). They are [CoClL(NCS)] (1), [CoL₂]·Cl·CH₃OH·H₂O (2), [CuL(NCNCN)]_n·nCH₃OH (3), [NiL(HL)]·ClO₄·CH₃OH (4) and [ZnClL(OH₂)]·CH₃OH (5). The compounds were characterized by physico-chemical methods. Structures of the complexes were further confirmed by single crystal X-ray diffraction. The metal ions in 1, 3, and 5 display square pyramidal coordination and 2 and 4 display octahedral coordination. The inhibitory effects of the compounds on Jack bean urease were evaluated. The results showed that 3 has effective urease inhibitory activity, with IC₅₀ value of (7.3?±?1.0) μmol L^?1.     

Spectral luminescent properties of 5-(2-hydroxyphenyl)-3-ethyl-1-(pyridin-2-yl)-1Н-1,2,4-triazole and its Be(II) complex

Russian Journal of General Chemistry - The interaction of 4-oxo-1,3-benzoxazinium perchlorate with 2-pyridylhydrazine has given 5-(2-hydroxyphenyl)-3-ethyl-1-(pyridin-2-yl)-1Н-1,2,4-triazole...     

Facile Synthesis of 2-(4-Hydroxybiphenyl-3-yl)-1H-indoles from Anilines and 5′-Bromo-2′-hydroxyacetophenone

2-Arylindoles are attractive scaffolds because they are found in many pharmacologically active molecules. In this study, we describe the facile synthesis of diverse 2-(2-hydroxyphenyl)-1H-indoles from anilines and 5′-bromo-2′-hydroxyacetophenone in two steps using palladium-catalyzed indole cyclization as a key reaction. The indole cyclization was primarily controlled by the substituent properties of anilines. Suzuki-coupling reactions of 2-(5′-bromo-2′-hydroxyphenyl)-1H-indoles with arylboronic acids provided the corresponding 2-(4-hydroxybiphenyl-3-yl)-1H-indoles in moderate yield.     

1H-3-(2-pyridyl)-5-(3-pyridyl)-1,2,4-triazole (2,3′-Hbpt) as ligand in Cd(II) complexes: synthesis,crystal structures,and fluorescence

Hydrothermal reactions of 1H-3-(2-pyridyl)-5-(3-pyridyl)-1,2,4-triazole (2,3′-Hbpt) with CdCl₂ and CdI₂ yielded three new coordination polymers, {[CdCl(2,3′-bpt)(H₂O)]·2H₂O}_n (1), {[Cd₂I₃(2,3′-H_0.5bpt)₂]}_n (2), and [CdI₃(2,3′-Hbpt)](2,3′-H₂bpt)·H₂O (3). Structural analysis reveals that 1 has a 1-D double chain structure; in 2, 2,3′-bpt bridges adjacent Cd(II) ions to form a 1-D twofold helical chain, which further connects via μ₂-I^-, giving a 2-D grid structure in the ab plane; 3 is mononuclear. These complexes are further connected through weak hydrogen bonding interactions, and/or weak π···π stacking interactions, to generate 3-D supramolecular structures. The fluorescence properties of 1 and 2 have been investigated in the solid state at room temperature.     

Synthesis of 5-substituted-3-[(2′S,3′S)-3′-hydroxy-2′-hydroxymethyltetrahydrofuran-3′-yl]-1,2,4-oxadiazoles and their epimers

5-Phenyl-3-[(2′R,3′S)-3′-hydroxy-2′-dimethoxymethyltetrahydrofuran-3′-yl]-1,2,4-oxadiazole 10a and its epimer 11a, 5-methyl-3-[(2′R,3′S)-3′-hydroxy-2′-dimethoxymethyltetrahydrofuran-3′-yl]-1,2,4-oxadiazole 10b and its epimer 11b were synthesized from cyanohydrin benzoates 8a, 9a and cyanohydrin acetates 8b, 9b, respectively, by treatment with hydroxylamine in methanol via intramolecular transacylation and subsequent cyclization of the corresponding amidoximes. Hydrolysis and reduction of the dimethoxymethyl groups in the above compounds gave the desired compounds 12a, 13a, 12b and 13b.     

Synthesis and crystal structures of N′-(3-ethoxy-2-hydroxybenzylidene)-3-methylbenzohydrazide and its dioxomolybdenum(VI) complex

A new hydrazone N′-(3-ethoxy-2-hydroxybenzylidene)-3-methylbenzohydrazide (H₂L), derived from condensation of 3-ethoxysalicylaldehyde with 3-methylbenzohydrazide, and its dioxomolybdenum(VI) complex [MoO₂L(CH₃OH)], have been prepared and characterized by physico-chemical methods and single crystal X-ray diffraction. The hydrazone coordinates to Mo through the phenolate O, imine N, and enolic O. The Mo is six-coordinate in a distorted octahedral geometry, with the three donors of L and one oxo defining the equatorial plane, and with one methanol and another oxo occupying the axial positions. The bond values especially for those related to the donors in the complex are different from those in H₂L.     

Novel 2′-(pyridin-4-yl)-5′-(pyridin-2-yl)-1′-(pyridin-2-yl)methylpyrrolidinyl[60]fullerene-hydroxyoxo(5,10,15,20-tetraphenyl-21H,23H-porphynato) molybdenum(V) dyads

Interaction between hydroxyoxo(5,10,15,20-tetraphenylporphyrinato)molybdenum(V) and 2′-(pyridin-4-yl)-5′-(pyridin-2-yl)-1′-(pyridin-2-yl)methylpyrrolidinyl[60]fullerene in toluene has been studied by means of spectrophotometry. The reaction proceeds via two stages: rapidly established equilibrium between the reactants and their molecular complex 1: 1 [K = (1.97 ± 0.52) × 10⁴ L/mol] followed by slow irreversible displacement of hydroxy group into the second coordination sphere to form cationic outer sphere complex (k = 0.26 L s^?1 mol^?1). The effect of fullerene fragment on pyridine fragments coordination has been considered.     

Synthesis,Crystal Structure and Fluorescent Properties of a Cadmium(Ⅱ) Complex with 3-(Pyridin-4-yl)-5-(pyrazin-2-yl)-1H-1,2,4-triazole

Compound [Cd_(1.5)(ppt)Br_2(H_2O)]_(2n)(1),where Hppt = 3-(pyridin-4-yl)-5-(pyrazin-2-yl)-1H-1,2,4-triazole,has been synthesized under hydrothermal conditions and characterized by elemental analysis,IR spectra,powder XRD,and X-ray diffraction.Compound 1 crystallizes in the triclinic system,space group P1 with a = 7.4402(6),b = 8.0570(7),c = 12.8674(11) ?,α = 89.7300(10),β = 89.8570(10),γ = 68.3910(10)°,V = 717.13(10) ?3,Z = 1,Dc = 2.638 g/cm3,μ = 7.824 mm~(-1),F(000) = 534,the final R = 0.0324 and w R = 0.1084 for 2324 observed reflections with I 2σ(I).X-ray diffraction analyses revealed that complex 1 is a 2D layered coordination polymer constructed from the linkage of [Cd_3(μ-Br)_4] trinuclear units with ppt-spacers,and a 3D supramolecular architecture is further assembled in 1 via hydrogen-bonding contacts.Fluorescence measurements show that 1 has medium fluorescent emission at 450 nm.     

Synthesis of electroactive hydrazones derived from 3-(10-alkyl-10H-phenothiazin-3-yl)-2-propenals and their corresponding 3,3′-bispropenals

3-(10-Alkyl-10H-phenothiazin-3-yl)-2-propenals and their corresponding 3,3′-bispropenals that represent a previously unexplored class of functionalised phenothiazine derivatives were prepared upon reacting N-alkylated 3-bromo- and 3,7-dibromo-10H-phenothiazines with acrolein diethyl acetal under Pd catalysis. The obtained heterocyclic 2,3-unsaturated aldehydes were condensed with N-methyl-N-phenylhydrazine and N,N-diphenylhydrazine resulting in mono- and dihydrazones that act as effective hole transporting materials. Thermal, optical, electrochemical and photophysical properties of the synthesised new organic electroactive derivatives have been investigated.     

Aromatic Multicarboxylate Ligands Tuned One-and Three-dimensional Zn(Ⅱ) Coordination Polymers Based on 3-(1H-pyrazol-4-yl)-5-(pyridin-3-yl)-1,2,4-triazole

Two aromatic multicarboxylate ligands tuned Zn(Ⅱ) coordination polymers, namely, {[Zn_(0.5)(H_2L)(tp)_(0.5)(H_2O)]H_2O}_n(1) and {[Zn_2(HL)(btc)(H_2O)]H_2O}_n(2)(H_2L = 3-(1 Hpyrazol-4-yl)-5-(pyridin-3-yl)-1,2,4-triazole, H_2tp = terephthalic acid; H_3 btc = 1,3,5-benzenetricarboxylic) have been synthesized. Their structures were characterized by single-crystal X-ray diffraction analysis, elemental analyses and infrared spectra. Compound 1 possesses a one-dimensional chain structure and is finally extended into a three-dimensional supramolecular architecture though hydrogen bonding interactions. Compound 2 shows a three-dimensional framework. Meanwhile, compounds 1 and 2 exhibit luminescent emission in the solid, and can be investigated as potential luminescent materials.     

Crystal Structure and Spectra Characters of 2-Benzoly-3-(4-(1,2,4-triazole)-5-anilino-thiophene and 2-(4-Methyl-benzoly)-3-(4- chlrolphenyl)-3-(1,2,4-triazole)-5-anilino-thiophene

Triazole derivatives are widely studied, because they represent the largest group of modern fungicides and are widely used both in human and veterinary therapy and in agriculture. We synthesized the title compound in which the thiophene ring was substituted by a 1,2,4-triazole group, a phenacyl group, a phenylaminol group and a benzene ring.