Synthesis,characterization, and pharmacological evaluation of the proton transfer salts of 2-aminobenzothiazole derivatives with 5-sulfosalicylic acid and their Cu(II) complexes

Abstract

Two proton transfer compounds, formed between 2-aminobenzothiazole derivatives (2-aminobenzothiazole (abt) and 2-amino-6-ethoxybenzothiazole (EtOabt)) and 5-sulfosalicylic acid dihydrate (H₃ssa) as parent compounds, (Habt)⁺(H₂ssa)^? (1) and (HEtOabt)⁺(H₂ssa)^? (2) and their Cu(II) complexes (3 and 4, respectively) have been prepared and characterized using spectroscopic techniques. The single crystal X-ray diffraction method has been also applied to 3 and 4. Although 3 has a distorted octahedral form, 4 exhibits a distorted square pyramidal geometry. All compounds, including saline and diclofenac sodium as standards, have been evaluated pharmacologically for their anti-inflammatory and analgesic activities in rats and mice. Parent compounds (abt, EtOabt, and H₃ssa) 3 and 4 show significant anti-inflammatory and analgesic activities as compared with control compounds.     

Thermal Decomposition of Cu(II) Complexes with 2-Chloro- and 2,6-Dichlorobenzoic Acid and Imidazole

The reaction products of Cu(II) 2-chlorobenzoate and the imidazole (1), and of Cu(II) 2,6-dichlorobenzoate and the imidazole (2) formulated as CuL’₂⋅2imd⋅2H₂O and CuL”₂⋅2imd⋅2H₂O (L’=C₇H₄ClO₂ ⁻, L”=C₇H₃Cl₂O₂ ⁻, imd=imidazole), were prepared and characterized by means of spectroscopic measurements and thermochemical properties. The blue (1) and green (2) complexes were obtained as solids with a 1:2:2 molar ratio of metal to carboxylate ligand to imidazole. When heated at a heating rate of 10 K min⁻¹ the hydrated complexes, (1) and (2), lose some of the crystallization water molecules and then decompose to gaseous products. This revised version was published online in August 2006 with corrections to the Cover Date.     

Synthesis,characterization, and biological evaluation of Cu(II) complexes with the proton transfer salt of 2,6-pyridinedicarboxylic acid and 2-amino-4-methylpyridine

A proton transfer compound, (Hamp)⁺(Hdipic)^??·?1.5H₂O (1), and Cu(II) complexes, [Cu(dipic)(amp)(H₂O)]?·?[Cu(dipic)(amp)]?·?H₂O?·?CH₃COOH (2) and [Cu(dipic)(amp)Cu(dipic)(amp)(H₂O)Cu(dipic)(amp)(H₂O)]?·?3H₂O (3), have been synthesized from 2,6-pyridinedicarboxylic acid (H₂dipic) and 2-amino-4-methylpyridine (amp). They have been characterized by elemental, spectral (¹H-NMR, IR, and UV-Vis), and thermal analyses. In addition, magnetic measurements and single crystal X-ray diffraction have been applied to 2 and 3. The crystal structure of 2 consists of two independent and different cationic sites with Cu²⁺ ions. Cu1 is four-coordinate in a distorted square planar geometry and Cu2 is five-coordinate in a distorted square pyramid. Compound 3 has three independent and different cationic sites of Cu²⁺ ions. Cu1 is four-coordinate in a distorted square planar geometry and Cu2 and Cu3 have five-coordinate, distorted square-pyramidal sites. Inhibitory effects of 1, 2, and 3 have been studied and compared with starting compounds (amp and H₂dipic) on bacterial growth of Staphylococcus aureus and Escherichia coli cultures. Compounds 2 and 3 prevent bacterial growth although 1 has no effect. Compounds 2 and 3 are more effective than amp and H₂dipic, at similar concentrations on preventing bacterial growth for both organisms.     

Synthesis, characterization and biological evaluation of a novel Cu(II) complex with the mixed ligands 2,6-pyridinedicarboxylic acid and 2-aminopyridine

A novel bridged binuclear Cu(II) complex with mixed ligands, di-μ-(2-aminopyridine(N,N′))-bis[(2,6-pyridinedicarboxylate)aquacopper(II)] tetrahydrate, formulated as [Cu(μ-ap)(dipic)(H₂O)]₂·4H₂O (1) (dipic = 2,6-pyridinedicarboxylate, ap = 2-aminopyridine), has been synthesized and characterized by elemental, spectral (IR and UV–Vis.), thermal analysis, magnetic measurements and single crystal X-ray diffraction analysis. The central Cu(II) ion resides on a centre of symmetry in a distorted square-pyramid coordination environment comprising of two N atoms, one from dipic and one from the ap ring, two carboxylate O atoms from dipic, and one O atom from water. Intermolecular N–HO and O–HO hydrogen bonds and π–π stacking interactions seem to be effective in the stabilization of the crystal structure. The free ligands and the complex were also evaluated for their antimicrobial and radical scavenging activities (DPPH = 1,1-diphenyl-2-picrylhydrazyl hydrate) using in vitro microdilution methods. Antimicrobial screening of the free ligands and their complex showed that the free ligands and the complex possess antifungal activity against Candida sp.     

2-D coordination polymers of copper and cobalt with 3,4-pyridinedicarboxylic acid: synthesis,characterization, and crystal structures

Two new complexes involving 3,4-pyridinedicarboxylic acid (3,4-H₂pdc), copper(II) and cobalt(II) complexes, {[Cu(3,4-Hpdc)₂(H₂O)₂]·2dmso}_n (1) and {[Co(3,4-Hpdc)₂(H₂O)₂]·2H₂O·2dmso}_n (2) (dmso = dimethylsulfoxide), have been synthesized by the diffusion method and characterized by elemental analysis, IR spectroscopy, thermal analysis, powder and single-crystal X-ray diffraction analysis, and electron paramagnetic resonance (EPR). In both compounds, the metal coordination sphere is composed of a trans-MO₄N₂ core and adopts a distorted octahedral geometry in accordance with X-ray diffraction and EPR results. 3,4-Hpdc^? ligands bridge the metal centers giving two-dimensional (2-D) coordination polymers with four-connected uninodal nets of (4,4) topology.     

Synthesis of Eu(III) and Tb(III) complexes with novel pyridine dicarboxylic acid derivatives and their fluorescence properties

Starting from pyridine-2,6-dicarboxylic acid (DPA), a series of novel pyridine-2,6-dicarboxylic acid derivatives were synthesized. In these compounds, 4-(hydroxymethyl)pyridine-2,6-dicarboxylate (4-HMDPA) and 4-[(bis-carboxymethyl-amino)-methyl]-pyridine-2,6-dicarboxylic acid (4-BMDPA) were used as multifunctional ligands to coordinate with Tb(III) and Eu(III) and the complexes were prepared. The fluorescence properties of the solid complexes and their solutions were investigated in detail. The results indicated that the weak election-withdrawing group 4-hydroxymethyl in 4-position of pyridine in 4-HMDPA could weaken the fluorescence intensity of the lanthanide complexes. The contradistinctive experimental results showed that the fluorescence intensities of these complexes are related to pH values of the aqueous solutions and the dipole moments of solvent molecules: in the neutral aqueous solutions, the fluorescence intensities of these complexes were strongest, while the dipole moments were lower when the fluorescence intensities were stronger. 4-BMDPA is the better sensitizer and may be used as time-resolved fluoroimmunoassay. __________ Translated from Chemical Journal of Chinese Universities, 2006, 27(3) (in Chinese)     

稀土-2,6-吡啶二甲酸-氧化三苯基膦配合物的合成及其荧光性质

稀土离子尤其是Sm,Eu,Tb,Dy因为其良好的荧光性能而得到了广泛的研究和应用[1,2]。吡啶二甲酸和氧化三苯基膦这两种配体有较大范围的共轭π键,在近紫外区又都有较宽的吸收带和较强的吸收峰,与稀土离子配位后可以构成有效的能量传递体系,将它们在近紫外区吸收的能量有效地传递给     

The synthesis and structure of a novel 1D copper(II) weak coordination polymer with 2,6-pyridinedicarboxylic acid

A novel copper complex, [Cu(dipic)(H₂O)₂] _n (H₂dipic?=?2,6-pyridinedicarboxylic acid), was synthesized and its crystal structure determined by X-ray diffraction. The complex has a polymeric structure of infinite one-dimensional (1D) zigzag chains, consisting of six-coordinate Cu(II) units. Each copper(II) ion is in a distorted octahedral environment with a CuNO₅ core: two oxygen atoms and one nitrogen atom from one dipic anion, one oxygen atom from an adjacent dipic ligand and two oxygen atoms from coordinated water. Each dipic anion connects two copper ions via a μ₂-oxygen atom. The zigzag 1D-chains are linked by extensive hydrogen bonds to form 2D infinite sheets.     

Copper(II) complexes with pyridine-2,6-dicarboxylic acid from the oxidation of copper(I) iodide

Via an oxidation reaction of Cu(I) iodide with pyridine-2,6-dicarboxylic acid (H₂L) in DMF three copper(II) complexes, [(CH₃)₂NH₂]₂[CuL₂] (1), K₂[CuL₂]?H₂L?H₂O (2) and [Cu(L)(H₂O)]_n (3), were synthesized and characterized. The structures of 1–3 were determined by single crystal X-ray diffraction studies. In-situ DMF decomposition produces dimethylamine base under solvothermal conditions and a proton transfer reaction takes place for the complex formation of 1. 3-D networks are stabilized in 1 and 2 via hydrogen bonds. Complex 3 is a 1-D coordination polymer with Cu-O semi-coordination bonds. Thermal decomposition of the complexes results in the corresponding metal oxides. Also, the electrochemical behavior of 1 was determined to be a metal-centered and diffusion-controlled, one-electron reduction process.     

配合物[RE2(H2L)2(HL)2(2,6-H2PDA)(H2O)2]•2H2O的合成、 晶体结构及其与DNA作用方式初探

以N-(2-异丙酸)-邻羟基苯甲酰腙(C10H10N2O4, H3L)、2,6-吡啶二甲酸(2,6-H2PDA)与RE(NO3)3•nH2O (RE＝Pr, Eu)在室温下反应, 合成了配合物1 [Pr2(H2L)2(HL)2(2,6-H2PDA)(H2O)2]•2H2O和配合物2 [Eu2(H2L)2(HL)2(2,6-H2PDA)- (H2O)2]•2H2O, 对其进行了元素分析、红外光谱、紫外光谱等表征, 测定了两种配合物的晶体结构. 通过紫外吸收光谱、荧光发射光谱和稳态荧光猝灭方法及其与溴化乙锭(EB)的竞争实验研究了两种配合物与小牛胸腺DNA的作用情况. 结果表明, 两种配合物与小牛胸腺DNA均是以插入方式结合的.     

Synthesis and Crystal Structure of a Palladium(II) Coordination Polymer [Na_2Pd(2,6-pydc)_2(H_2O)_6]_n

A novel coordination polymer [Na2Pd(2,6-pydc)2(H2O)6]n (2,6-H2pydc = 2,6-pyri- dinedicarboxylic acid) has been synthesized and its crystal structure was determined by single-crystal X-ray diffraction. The crystal belongs to the monoclinic system, space group P21/c, with a = 11.962(2), b = 6.5552(13), c = 12.673(3) , β = 91.72(3)°, V = 993.3(3) 3, Z = 2, Mr = 590.68, Dc = 1.975 g/cm3, μ = 1.059 mm-1, F(000) = 592, the final R = 0.0211 and wR = 0.0454. In the crystal the Pd(II) ion adopts a distorted four-coordinated square-planar geometry and bonds to two bidentate 2,6-pyridinedicarboxylate molecules through caronyl oxygen and pyridine nitrogen atoms. The title complex exhibits a novel three-dimensional network structure.     

4-Aminopyridine Adducts of Cu(II) 2-Chloro- and 2,6-Dichlorobenzoate

Reaction products of Cu(II) 2-chlorobenzoate and 4-aminopyridine (1), and of Cu(II) 2,6-dichlorobenzoate and 4-aminopyridine (2) formulated as CuL′₂(4-apy)₂ and CuL″₂(4-apy)₂((L′ =C₇H₄ClO^? ₂,L″ =C₇H₃Cl₂O^? ₂, 4-apy = 4-aminopyridine), were prepared and characterized by structural and spectroscopic measurements, thermochemical properties and magnetic susceptibilities. Compound (1) crystallizes in the orthorhombic space group Pbca, a = 8.875(2), b = 13.236(4), c = 21.603(3) Å, V = 2537.7(10) ų, Z = 4, and the Compound (2) crystallizes in the monoclinic space group P2₁/c, a = 11.516(2), b = 8.749(2), c = 13.469(3) Å, β = 103.36(3)°, V = 1320.3(5) ų, Z = 2. Complexes (1) and (2) decomposes to gaseous products at 473 and 513 K, respectively.     

Spectrophotometric Study of Mithramycin Complexes with Cu(II), Fe(III) and Tb(III)

Abstract

The coordination of the anticancer drug mithramycin to Tb(III), Fe(III) and Cu(II) was studied in aqueous solution using absorption measurements. The stability constants were calculated from equilibrium competition experiments by means of the SQUAD program. For both first ions, the competitor was oxalic acid and for the latter the competitor was the Cu(II) ions. Cu(II) at pH 7.5, Fe(III) at pH 3.5 and Tb(III) at pH 5.5 formed respectively 1:2, 1:3 and 1:4 metal-to-ligand species.     

Preparation and characterization of some metal(II) complexes of isocinchomeronic acid and X-ray crystal structure ofcis-diaquabis(hydrogen isocinchomeronato)manganese(II)

The reactions between Mn(II), Co(II), Ni(II), and Zn(II) ions with isocinchomeronic acid (H₂-isocin) afforded complexes of the general formula M(H-isocin)₂-2H₂O, whereas Fe(II) gives both red and deep red-brown products of the same formula. Various physical measurements suggest that the complexes of M = Co, Ni, Zn, and Fe (brown) are octahedrally coordinated by two aqua ligands and twotrans-N,O-bidentate H-isocin^– anions with dimeric hydrogen bonding. Those for M = Mn and Fe (red) are the correspondingcis isomers. The structure of the manganese complex as determined by X-ray crystallography exhibitsC ₂ molecular symmetry with Mn-N = 2.279(2), Mn-O(H-isocin)^– = 2.196(2), and Mn-O(aqua) = 2.137(2) Å. Each aqua ligand forms two donor O-H O hydrogen bonds with carboxy groups of different molecules in adjacent chains.     

Synthesis and Crystal Structure of [Cu2（DMF）（H2O）（C7H4NO4）2（C7H3NO4）]2·3.5DMF

A new copper（H） complex [Cu2（DMF）（H2O）（C7H4NO4）2（C7H3NO4）]2-3.5DMF has been synthesized and its structure was determined by single-crystal X-ray diffraction. The crystal is of triclinic, space group P1^- with a = 10.722（3）, b = 18.170（4）, c = 20.923（7）A,α = 105.297（9）, β = 101.701（10）, γ = 105.74（1）°, V= 3615（1）A^3, Z = 2, C58.50H64.50Cu4N1l.50O3150, Mr = 1686.90, Dc = 1.550 g/cm^3,μ= 1.255 mm^-1, F（000） = 1728.00, T = 150（2） K, the final R = 0.0640 and wR = 0.173 for 11310 observed reflections with I 〉 2σ（I）. In the crystal, each formular unit consists of two dinuclear copper（H） compounds, between which the O-H…O hydrogen bonds exist. Each Cu^Ⅱ cation is six-coordinated in an octahedral geometry. The intermolecular hydrogenbonding interaction leads to a 3-D framework of the title compound.     

Fe(III) and cobalt(II) coordination compounds of 5-bromo-6-methyl-2-morpholinepyrimidinium-4-amine pyridine-2,6-dicarboxylate

New coordination compounds, (bmmpaH)[Fe(pydc)₂] · (EtOH)_0.8(H₂O)_0.2 (1), (8QH)[Fe(pydc)₂] · H₂O (2), (2ampyH)₂[Mn(pydc)₂] · H₂O (3), (2ampyH)[Cr(pydc)₂](2ampy)_0.5 · H₂O (4), [Co(H₂O)₅-μ-(pydc)Co(pydc)] · 2H₂O (5), [Ni(pydcH)₂] · H₂O (6), and [Cu(pydcH)₂] (7), where bmmpa, 8Q, 2ampy, pydcH₂ are 5-bromo-6-methyl-2-morpholinepyrimidine-4-amine, 8-hydroxyquinoline, 2-amino-6-methylpyridine, and pyridine-2,6-dicarboxylic acid, respectively, have been synthesized and structurally characterized by elemental analyses, infrared, UV spectroscopic methods, and X-ray crystallography. Metal ions of 1 and 5 are six-coordinate with distorted octahedral geometries. Compound 1 is an anionic mononuclear complex and 5 is a binuclear compound constructed from cationic and anionic parts. The crystal data of 5 reveal that the cationic part is formed by five terminal waters and one μ-carboxylate oxygen O2 from the anionic portion and the anionic complex is built from two deprotonated (pydc)^2? moieties. In the compounds, pydcH₂ is tridentate by one nitrogen of pyridine ring and two oxygens of carboxylate.     

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

A new macrocyclic ligand, 1,3,5-triaza-2,4:7,8:16,17-tribenzo-9,12,15-trioxacyclooktadeca-1,5-dien (L) was synthesized by reaction of 2,6-diaminopyridine and 1,7-bis(2-formylphenyl)-1,4,7-trioxaheptane. Then, its Cu(II), Ni(II), Pb(II), Co(III) and La(III) complexes were synthesized by template effect by reaction of 2,6-diaminopyridine and 1,7-bis(2-formylphenyl)-1,4,7-trioxaheptane 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, UV–Vis spectra, magnetic susceptibility, thermal gravimetric analysis, conductivity measurements, mass spectra and cyclic voltammetry. All complexes are diamagnetic and Cu(II) complex is binuclear. The Co(II) was oxidized to Co(III). The comparative electrochemical studies show that the nickel complex exhibited a quasi-reversible one-electron reduction process while copper and cobalt complexes gave irreversible reduction processes in DMSO solution.     

Crystal Structure of a Novel Complex Na_4[Y(PDC)_2(BTC)]·5H_2O with One-Dimensional Helical Network Structure (H2PDC = 2,6-Pyridinedicarboxylic acid)( H_3BTC = 1,3,5-Benzenetricarboxylic acid )

1 INTRODUCTION The assembly of coordination networks is a field of increasing interest[1~4]. Research along this line is induced by the idea that coordination networks have potential technological applications such as optoele- ctronic devices and microporous materials for shape and size separation and catalysis[5~7]. In this paper, there has been current interest in using polycarboxy- late as anion linking groups to support stable poly- meric coordination open frameworks with transition m…     

Synthesis,crystal structures,and properties of copper(II) complexes with 2,6-bis(benzimidazol-2-yl)pyridine

Three new mononuclear copper(II) complexes, [CuL(2-fca)(CH₃OH)]ClO₄?·?CH₃OH (1), [CuL(m-nba)(CH₃OH)]ClO₄ (2), and [CuL(pic)(ClO₄)]?·?CH₃OH (3), were synthesized and structurally characterized, where L is 2,6-bis(benzimidazol-2-yl)pyridine, while 2-fca, m-nba, and pic are the anions of 2-furoic acid, m-nitrobenzoic acid, and picolinic acid, respectively. All of them were characterized by elemental analysis, infrared, UV-Vis, and X-ray crystallography. In 1 and 2, the Cu(II) resides within a distorted square-pyramidal N₃O₂ coordination sphere with three nitrogens of L, one carboxylate oxygen, and one methanol. In 3, Cu(II) is coordinated with three nitrogens of L, one nitrogen and one oxygen of picolinate, and one oxygen of perchlorate in a distorted octahedral geometry. Two molecules of 1, 2, and 3 are interacted by intermolecular hydrogen-bonding interactions and strong π–π stacking interactions to form a dinuclear structural unit. The dinuclear units are further connected by H-bonds via perchlorate or lattice methanol to form a 1-D chain for 1 and 2-D network structures for 2 and 3. Hydrogen-bonding and π–π stacking interactions are important for the stabilization of the final supramolecular structures of the three complexes.