Syntheses,characterizations, and antimicrobial activities of binuclear ruthenium(III) complexes containing 2-substituted benzimidazole derivatives

Binuclear ruthenium(III) complexes [RuX₃L]₂?·?nH₂O (X?=?Cl, L?=?L¹, L², L³; n?=?1, L⁴ and L⁵, X?=?Br; L?=?L³), [RuX₃L_1.5]₂?·?nH₂O (X?=?Br, L?=?L¹; n?=?0, L⁴; n?=?6 and L⁵; n?=?10), and [RuX₃L₂]₂ (X?=?Br, L?=?L²) have been isolated by treatment of hydrated RuX₃ (X?=?Cl/Br) in acetone with 2-(2′-aminophenylbenzimidazole) (L¹), 2-(3′-aminophenylbenzimidazole) (L²), 2-[(3′-N-salicylidinephenyl)benzimidazole] (L³), 2-(3′-pyridylbenzimidazole) (L⁴), and 2-(4′-pyridylbenzimidazole) (L⁵) in acetone. The complexes were characterized by elemental analysis, conductivity and magnetic susceptibility measurements, IR, electronic, EPR, and mass spectral studies. The complexes were dimeric; based on analytical and spectral studies, an octahedral geometry was proposed for the complexes. The synthesized complexes were screened against Gram-positive and Gram-negative bacteria and fungi.     

Preparation and structural characterization of oxovanadium(V) complexes with Schiff bases and their inhibition studies on Helicobacter pylori urease

A series of structurally similar dinuclear oxovanadium(V) complexes, [VO₂L]₂ (L?=?L¹?=?2-[(2-methylaminoethylimino)methyl]phenolate (1); L?=?L²?=?2-[(2-ethylaminoethylimino)methyl]phenolate (2); L?=?L³?=?2-[(2-isopropylaminoethylimino)methyl]phenolate (3)), has been synthesized and characterized by physico-chemical methods and single-crystal X-ray diffraction. The V in each complex is octahedral, with three donors of L and one oxo defining the equatorial plane, and with two oxos occupying the axial positions. The complexes were tested for their urease inhibitory activities. The inhibition rate (%) of 1, 2, and 3 at 100?µmol?L^?1 on urease are 67?±?1, 53.5?±?0.9, and 44?±?1. The relationship between structures of the complexes and the urease inhibitory activities indicates that shorter terminal groups of the complexes have stronger activities against urease. Molecular docking study of the complexes with the Helicobacter pylori urease was performed.     

Syntheses of phenoxo-bridged Zn(II) and metallamacrocyclic Hg(II) complexes of organochalcogen (Se,Te) substituted Schiff-bases: structure and DNA-binding studies of Zn(II) complexes

The coordination of organochalcogen (especially Se and Te) substituted Schiff-bases L¹H, L²H, L³H, and L⁴H toward Zn(II) and Hg(II) has been studied. Reactions of these ligands with ZnCl₂ in 1?:?1 molar ratio gave binuclear complexes [{2-[PhX(CH₂) _n N?=?C(Ph)]-6-[PhCO]-4-MeC₆H₂O}₂Zn₂Cl₂] (where X?=?Se, n?=?2 (1); X?=?Se, n?=?3 (2); X?=?Te, n?=?2 (3); and X?=?Te, n?=?3 (4)) with partial hydrolytic cleavage of proligands. In these complexes, two partially hydrolyzed ligand fragments coordinate tridentate (NOO) with two Zn's. Reaction of HgBr₂ with L¹H and L²H in 1?:?1 molar ratio gave monometallic complexes [C₆H₂(4-Me)(OH)[2,6-{C(Ph)?=?N(CH₂) _n Se(Ph)}₂HgBr₂]] (n?=?2 (5) or 3 (6)) and under similar conditions with L³H and L⁴H gave bimetallic complexes [C₆H₂(4-Me)(OH)[2,6-{C(Ph)?=?N(CH₂) _n Te(Ph)}₂Hg₂Br₄]] (n?=?2?(7) or 3 (8)) in which the ligands coordinate with metal through selenium or tellurium, leaving the imino nitrogen and phenolic oxygen uncoordinated. The proligands L¹H, L²H give 14- or 16-membered metallamacrocycles through Se–Hg–Se linkages and L³H, L⁴H give 16- or 18-membered metallamacrocycles through Te–Hg–Br–Hg–Te linkages. All the complexes were characterized by elemental analyses, ESIMS, FTIR, multinuclear NMR, UV-Vis, and conductance measurements. The redox properties of the complexes were investigated by cyclic voltammetry (CV). Complexes 1–4 exhibited ligand-centered irreversible oxidation processes. Complexes 5 and 6 showed metal-centered quasi-reversible single electron transfer, whereas dinuclear complexes 7 and 8 displayed two quasi-reversible, one-electron transfer steps. A single-crystal X-ray structure determination of 1 showed that the coordination unit is centrosymmetric with Zn(II) in square-pyramidal coordination geometry and the two square pyramids sharing an edge. The Zn?···?Zn separation is 3.232?Å. The DNA-binding properties of 1 and 3 with calf thymus DNA were explored by a spectrophotometric method and CV.     

Syntheses,crystal structures,and catalysis by polymeric dioxomolybdenum(VI) complexes with similar (iso)nicotinohydrazones

Polymeric dioxomolybdenum(VI) complexes, [MoO₂L]_n (L?=?L¹?=?N′-(2-hydroxybenzylidene)nicotinohydrazide for 1, L?=?L²?=?N′-(2-hydroxy-5-methoxybenzylidene)isonicotinohydrazide for 2), were prepared and characterized by physico-chemical, spectroscopic methods, and single-crystal X-ray determination. Complex 1 crystallizes in the orthorhombic space group P2₁2₁2₁ with a?=?7.6568(4), b?=?11.6315(7), c?=?15.2211(9)?Å, V?=?1355.59(13)?ų, Z?=?4, R ₁?=?0.0181, wR ₂?=?0.0464, and S?=?1.097. Complex 2 crystallizes in the monoclinic space group P2 ₁ /n with a?=?11.2516(6), b?=?11.8134(7), c?=?12.4371(6)?Å, β?=?116.2210(10)°, V?=?1483.02(14)?ų, Z?=?4, R ₁?=?0.0399, wR ₂?=?0.0874, and S?=?1.096. X-ray analysis indicates that Mo in each complex is octahedral with two oxo groups and N₂O₂ donor set of the nicotinohydrazone or isonicotinohydrazone. The complexes are efficient catalysts for oxidation of olefins.     

Comment on the section: “Antioxidant measurements and hydroxyl radical scavenging activity” in synthesis,characterization, DNA binding,and antioxidant activities of four copper(II) complexes containing N-(3-hydroxybenzyl)-amino amide ligands,by Zhi Li-Hua,Wu Wei-Na,Wang Yuan,Sun Guang,J. Coord. Chem., 66, 227 (2013)

Two structurally similar vanadium(V) complexes, [VOL¹L] (1) and [VOL²L] (2), where L¹ is the dianionic form of N′-(3,5-dibromo-2-hydroxybenzylidene)-4-methoxybenzohydrazide, L² is the dianionic form of N′-(3,5-dibromo-2-hydroxybenzylidene)nicotinohydrazide, and L is benzohydroxamate, were prepared and characterized by elemental analysis, infrared spectra, and single crystal X-ray diffraction. 1 crystallizes in the monoclinic space group P2₁/c, with unit cell dimensions a?=?12.0262(7), b?=?16.5629(9), c?=?12.3449(8)?Å, β?=?105.160(2)°, V?=?2373.4(2)?ų, Z?=?4, R₁?=?0.0376, wR₂?=?0.0844, GOOF?=?1.058; 2 crystallizes in the monoclinic space group P2₁/c, with unit cell dimensions a?=?10.6439(7), b?=?16.1968(9), c?=?13.1108(8)?Å, β?=?104.180(2)°, V?=?2191.4(2)?ų, Z?=?4, R₁?=?0.0521, wR₂?=?0.1142, GOOF?=?1.018. X-ray analysis indicates that vanadium in the complexes are coordinated by phenolate oxygen, imino nitrogen, and enolate oxygen of the hydrazone, two oxygens of the benzohydroxamate, and one oxo, generating octahedral coordination. Oxidations of olefins with the complexes as catalysts were evaluated. The complexes showed effective catalytic efficiency in oxidation of several aliphatic and aromatic substrates under mild conditions, using tert-butyl hydrogen peroxide as oxidant.     

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.     

Synthesis,structure and antimicrobial study of two new copper(II) complexes derived from N-(3-aminopropyl) benzylamine ligand (apba) and N-salicylidene-apba

Two new copper(II) complexes were synthesized by reaction of N-(3-aminopropyl)benzylamine (L1: apba, for complex 1) and N-salicylidene-apba (L2: for complex 2) with Cu²⁺. Crystals of complex 1 were orthorhombic, space group pccn, with a?=?15.2149(10), b?=?25.0071(16), c?=?7.6280(5)?Å and α?=?β?=?γ?=?90°. Complex 2 crystals were monoclinic, space group P2₁/c, with a?=?8.688(6), b?=?12.812(9), c?=?16.022(11)?Å and β?=?99.241(10)°. Structures of the two complexes were centro-symmetric and both Cu(II) atoms were four coordinate with a distorted square-planar geometry. The toxicity of the complexes was evaluated by testing antimicrobial activity against bacterial strands.     

Synthesis and structures of two molybdenum(VI) complexes derived from similar benzohydrazone ligands with catalytic properties

Two new structurally similar molybdenum(VI) complexes, [MoO₂L¹(CH₃OH)] (1) and [MoO₂L²(CH₃OH)] (2), where L¹ is the dianionic form of N′-(2-hydroxy-5-nitrobenzylidene)-2-methylbenzohydrazide and L² is the dianionic form of N′-(2-hydroxy-4-methoxybenzylidene)-2-methylbenzohydrazide, were prepared and structurally characterized by elemental analysis, infrared spectra, and single-crystal X-ray diffraction. 1 crystallizes in the monoclinic space group P2₁/c, with unit cell dimensions a?=?7.941(1), b?=?14.337(2), c?=?15.141(2)?Å, β?=?92.782(2)°, V?=?1721.8(4)?ų, Z?=?4, R₁?=?0.0286, wR₂?=?0.0650, GOOF?=?1.028. 2 crystallizes in the triclinic space group P-1, with unit cell dimensions a?=?8.003(1), b?=?10.608(1), c?=?10.880(1)?Å, α?=?95.745(2)°, β?=?97.627(2)°, γ?=?105.762(2)°, V?=?872.0(2)?ų, Z?=?2, R₁?=?0.0226, wR₂?=?0.0595, GOOF?=?1.116. X-ray analysis indicates that Mo in the complexes are coordinated by the phenolate oxygen, imino nitrogen, and enolate oxygen of the benzohydrazone, methanol, and two oxo groups, generating octahedral coordination. The oxidation of olefins with the complexes as catalysts was evaluated, indicating that the complexes showed excellent catalytic efficiency in oxidation of most aliphatic and aromatic substrates under mild conditions using tert-butyl hydrogen peroxide as oxidant.     

Cytotoxicity,apoptosis, interaction with DNA,cellular uptake,and cell cycle arrest of ruthenium(II) polypyridyl complexes containing 4,4′-dimethyl-2,2′-bipyridine as ancillary ligand

Two new ruthenium(II) polypyridyl complexes, [Ru(dmb)₂(DNPIP)](ClO₄)₂ (1) (DNPIP?=?2-(2,4-dinitrophenyl)imidazo[4,5-f][1,10]phenanthroline, dmb?=?4,4′-dimethyl-2,2′-bipyridine) and [Ru(dmb)₂(DAPIP)](ClO₄)₂ (2) (DAPIP?=?2-(2,4-diaminophenyl)imidazo[4,5f][1,10]phenanthroline), were synthesized and characterized. The DNA-binding behaviors of these complexes have been studied by UV-Vis absorption titration, viscosity measurements, and photocleavage. The DNA-binding constants are 7.39 (±0.16)?×?10⁴ (s?=?2.68) and 2.73 (±0.16)?×?10^4?(mol?L^?1)^?1 (s?=?0.64) for 1 and 2, respectively. Their evaluation as cytotoxic agents on different cancer cell lines was investigated with IC₅₀ values of 59.5, 51.3, and 70.3?µmol?L^?1 for 1, >100, 87.9, and 77.9?µmol?L^?1 for 2 against BEL-7402, HepG-2, and MCF-7 cells, respectively. Complex 1 is more active than 2 against selected cancer cell lines. The apoptosis induced by these complexes was studied. Cellular uptake showed that these complexes could enter into the cytoplasm and accumulate in the nuclei. The cell cycle arrest and antioxidant activity against hydroxyl radicals were also investigated.     

Synthesis,crystal structures and toxicity of bicadmium(ii) complexes with macrocyclic,hexaaza-bearing,hydroxyethyl pendants

Three bicadmium(II) complexes with hydroxyethyl pendants were synthesized by [2?+?2] Schiff-base condensation of 2-[bis(2-aminoethyl)amino]ethanol with sodium 2,6-diformyl-4-R-phenolate (for Complex 1, R?=?F; Complex 2, R?=?Cl; Complex 3, R?=?CH₃) in the presence of Cd²⁺. Crystals of 1 were monoclinic, space group P2₁/c, with a?=?16.251(9), b?=?21.424(11), c?=?12.994(7)?Å and β?=?106.622(9)°. Both Cd(II) atoms were heptacoordinated with monocapped-octahedral geometry. Complex 3 crystals were isolated as triclinic, space group P?1 with α?=?15.502(4), b?=?16.060(4), c?=?16.642(5)?Å and α?=?68.813(4), β?=?80.836(4), γ?= 86.551(4)°. The coordination number and coordination geometry of the Cd ion in one cationic unit of 3 are similar to that of 1, while in the other cationic unit, one Cd atom is N₃O₄ heptacoordinated and the other Cd atom has an N₃O₃ coordination environment and possesses a distorted octahedral geometry. The toxicity of these complexes was evaluated by testing antimicrobial activity against bacterial strands.     

Synthesis,characterization, interactions with DNA and bovine serum albumin (BSA), and antibacterial activity of cyclometalated iridium(III) complexes containing dithiocarbamate derivatives

Three mononuclear cyclometalated iridium(III) complexes having dithiocarbamate ligands, [Ir^III(2-C₆H₄py)₂(L)] (where 2-C₆H₄py?=?2-phenylpyridine; and L¹H?=?4-MePipzcdtH, L²H?=?MorphcdtH, and L³H?=?4-BzPipercdtH for 1, 2, and 3, respectively), were synthesized from [Ir(2-C₆H₄py)₂Cl]₂·1/4CH₂Cl₂ by displacing the two bridging chlorides with one dithiocarbamate ligand. The complexes were characterized using physicochemical and spectroscopic tools along with structural analysis of [Ir(2-C₆H₄py)₂(L²)] (2) by single crystal X-ray diffraction. Structural analysis of 2 showed a distorted octahedron in which the nitrogen donor of one 2-phenylpyridine and the carbon donor of another 2-phenylpyridine are in axial positions, trans to one another. Electrochemical analysis by cyclic voltammetry showed the irreversible two-electron equivalent reduction voltammograms of 1, 2, and 3 attributable to Ir(III) to Ir(I). Electronic characterizations of these complexes are consistent with significant delocalization of the sulfur electron density onto the empty metal d-orbital. The intercalative interaction of the complexes with calf thymus DNA was evaluated using absorption, fluorescence quenching, and viscosity measurements. The binding affinities of these complexes with bovine serum albumin were estimated in terms of quenching constants using the Stern–Volmer equation. Study of antibacterial activities of the complexes by agar disk diffusion against some species of pathogenic bacteria was also performed.     

Syntheses,structures, and spectroscopic properties of copper(II) and cobalt(III) complexes containing 1,4,7-tribenzyl-1,4,7-triazacyclononane ligand

Three new complexes [CuL(N₃)₂] (1), [CuL(SCN)₂] (2), and [CoL(SCN)₃] (3) (L?=?1,4,7-tribenzyl-1,4,7-triazacyclononane) have been synthesized and structurally characterized. Complex 1 crystallizes in monoclinic space group P2(1)/n with unit cell parameters a?=?14.105(7), b?=?8.999(5), c?=?21.603(11)?Å, β?=?100.470(7)°. While 2 crystallizes in triclinic space group P-1 with unit cell parameters a?=?9.6380(16), b?=?10.6993(18), c?=?15.798(3)?Å, α?=?106.636(3), γ?=?116.478(3)°. Complex 3 crystallizes in trigonal space group P–3c1 with unit cell parameters a?=?14.744(3), b?=?14.744(3), c?=?16.098(4)?Å, γ?=?120°. Elemental analysis, IR, UV-vis spectra of complexes 1–3 and ESR spectra of complexes 1–2 were also determined.     

Synthesis,crystal structures and fluorescence of cadmium(II) coordination polymers with derivatives of pyrazine-1,4-dioxide and thiocyanate as mixed-bridging ligands

Two Cd(II) coordination polymers have been synthesized with derivatives of pyrazine-1,4-dioxide and thiocyanate anion as bridging ligands and structurally determined by X-ray crystallography. Complex 1, [Cd(μ_1,3-SCN^?)₂(μ_1,6-L1)] _n (L1?=?2,5-dimethylpyrazine-1,4-dioxide), belongs to the triclinic, space group P 1 with a?=?5.7627(18)?Å, b?=?7.182(2)?Å, c?=?7.509(2)?Å, α?=?74.042(3)°, β?=?84.766(4)°, γ?=?88.162(4)°; complex 2, [Cd₂(μ_1,3-SCN^?)₄(μ₄-L2)] _n (L2?=?2,3,5,6-tetramethylpyrazine-1,4-dioxide), crystallizes in a monoclinic system with space group C2/m with a?=?10.194(4)?Å, b?=?13.491(6)?Å, c?=?8.140(3)?Å, β?=?120.372(4)°. Complex 1 shows a two-dimensional sheet structure, and in a direction the Cd(II) ions were coordinated by μ_1,3-SCN^? forming the one-dimensional chain and the L1 bridging ligand made the chains connect in the c direction leading to formation of a two-dimensional sheet on the ac plane. For 2 the one-dimensional chains in the a axis were constructed by coordination of μ_1,3-SCN^? bridging ligands with the Cd(II) ions, and in b and c directions the chains were joined by L2 bridging ligands leading to a three-dimensional structure. In 2 L2 displays a μ₄-bridging coordination mode. Both complexes exhibit strong fluorescence emission.     

Synthesis,characterization, crystal structures,enzyme inhibition,DNA binding,and electrochemical studies of zinc(II) complexes

Five zinc(II) complexes, [Zn(L¹)₂] (1), [Zn(L¹)₂(phen)H₂O]·H₂O (2), [Zn(L¹)₂(bipy)] (3), [Zn(L²)₂] (4), and [Zn(L²)₂(phen)] (5) (where L¹?=?4-nitrophenylacetate, L²?=?phenylacetate, phen?=?1,10-phenanthroline and bipy?=?2,2′-bipyridine), have been synthesized and characterized by elemental analysis, FT-IR, and multinuclear NMR. Complexes 2, 3, and 4 have been confirmed by single-crystal X-ray diffraction. In 2 and 3, zinc is bonded monodentate to two carboxylates exhibiting distorted trigonal bipyramidal and tetrahedral geometries, respectively, whereas in 4, the carboxylates are bridging bidentate in distorted tetrahedral geometry. The complexes have been screened for electro- and biological activities, including DNA interaction and enzyme inhibition studies. The effect of concentration of 1–5 on the activity of enzyme, alkaline phosphatase, showed that an increase in concentration of complex decreased the activity of the enzyme. Electrochemical behavior of HL¹, 2, and 3 was investigated by cyclic voltammetry and it was observed that ligand-centered electro-activity exhibits a proportionate change on complexation. The UV–visible spectroscopic and viscometric data indicate electrostatic and groove binding of the complexes with DNA. The binding constant and Gibb’s free energy values indicate the feasibility of the complex–DNA interaction and show potent biological activity of the complexes.     

Bis(2-Amino-5-bromopyrimidinium) Tetrahalometallates: Crystal structures of (2-amino-5-bromopyrimidinium)2 MCl4 (M = Co,Zn)

The reactions of metal(II) chlorides and bromides with 2-amino-5-bromopyrimidine (2-abpm) in neutral and acidic solution were investigated. The reaction with ZnCl₂, ZnBr₂, CoCl₂, CoBr₂ and MnCl₂ in acidic nitromethane solution gave complexes of the formula (2-abpmH)₂MX₄ (1, M?=?Zn, X?=?Cl; 2, M?=?Zn, X?=?Br; 3, M?=?Co, X?=?Cl; 4, M?=?Co, X?=?Br; 5, M?=?Mn, X?=?Cl). Crystals of 1 and 3 suitable for single crystal X-ray diffraction were obtained. Crystal data: For (1): triclinic, P-1, a?=?6.2485(13), b?=?9.0520(14), c?=?15.334(4)?Å, α?=?94.81(2), β?=?95.224(17), γ?=?98.027(17)°, V?=?851.1(3)?ų, Z?=?2, R?=?0.0596 for [|I|?≥?2σ(I)]. For (3): triclinic, P-1, a?=?6.2438(13), b?=?9.0597(15), c?=?15.318(3)?Å, α?=?94.749(18), β?=?95.343(15), γ?=?98.021(17)°, V?=?850.2(3)?ų, Z?=?2, R?=?0.0452 for [|I|?≥?2σ(I) ]. Variable temperature magnetic susceptibility data indicates weak antiferromagnetic interactions in the cobalt and manganese complexes.     

Synthesis,crystal structures,and biological activity of oxovanadium(V) complexes with similar tridentate hydrazone ligands

Two new oxovanadium(V) complexes, [VOL¹(OEt)(EtOH)] (1) and [VOL²(OMe)(MeOH)] (2), were prepared by reaction of [VO(acac)₂] (where acac?=?acetylacetonate) with N′-(3-bromo-2-hydroxybenzylidene)-4-methylbenzohydrazide (H₂L¹) in ethanol and N′-(3-bromo-2-hydroxybenzylidene)-4-methoxybenzohydrazide (H₂L²) in methanol, respectively. Crystal and molecular structures of the complexes were determined by elemental analysis, infrared spectra, and single-crystal X-ray diffraction. The V ions have octahedral coordination. Thermal stability and the inhibition of urease of the complexes were studied.     

Diorganotin(IV) complexes with furan-2-carbohydrazone derivatives: synthesis,characterization, crystal structure and antibacterial activity

Four new diorganotin(IV) complexes, R₂SnL (L?=?L^a: R?=?Me 1, Ph 2; L?=?L^b: R?=?Me 3, and Ph 4), have been synthesized by reaction of hydrazone ONO donors, 5-bromo-2-hydroxybenzaldehyde furan-2-carbohydrazone (H₂L^a) and 2-hydroxynaphthaldehyde furan-2-carbohydrazone (H₂L^b) with diorganotin(IV) dichloride in the presence of a base. The compounds have been investigated by elemental analysis and IR, ¹H NMR, and ¹¹⁹Sn NMR spectroscopies. Spectroscopic studies show that the hydrazone is a tridentate dianionic ligand, coordinating via the imine nitrogen and phenolic and enolic oxygens. The structures of H₂L^b and 3 have also been confirmed by X-ray crystallography. The results show that the structure of 3 is a distorted square pyramid with imine nitrogen in apical position. The in vitro antibacterial activities of ligands and complexes have been evaluated against gram-positive (Bacillus cereus and Staphylococcus aureus) and gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria. H₂L^a and H₂L^b show no activity but the diphenyltin(IV) complexes exhibit good activities towards two bacterial strains in comparison with standard bacterial drugs.     

Synthesis,characterization and crystal structures of two alkaline-earth metal complexes of olsalazine

Two one-dimensional linear coordination polymers, [Mg(L)?·?4(H₂O)] (H₂L?=?olsalazine) and 2 [Ca(L)?·?4(H₂O)] were obtained from self-assembly of CaCl₂ or MgSO₄ with olsalazine and their structures determined by single crystal X-ray diffraction. Both complexes are one-dimensional polymers, for complex 1 with crystal data: P2(1)/c, a?=?9.5224(18), b?=?11.309(2), c?=?16.211(3)?Å, β?=?106.648(3)°, V?=?1672.6(6)?ų, Z?=?4, R ₁?=?0.0695, wR ₂?=?0.2183, for complex 2 with crystal data: P4(3)2(1)2, a?=?10.4006(2), b?=?10.4006(2), c?=?32.0746(10)?Å, V?=?3469.59(14)?ų, Z?=?8, R ₁?=?0.0332, wR ₂?=?0.1015. In the complexes, Mg and Ca adopt totally different coordination modes. Alkaline-earth Mg is six-coordinate octahedronal geometry, however, in 2, the local coordination geometry around calcium atom can be best described as a slightly distorted pentagonal bipyramid crystallizing in a homo-chiral space group. Olsalazine in both compounds also adopts dissimilar coordination modes.     

Syntheses,structures, and properties of CdII and CoII complexes with 5-(pyridin-4-yl)isophthalate

A N-donor containing carboxylic ligand, 5-(pyridin-4-yl)isophthalic acid (H₂L), was applied to construct two new coordination polymers [Cd(L)(DMF)] _n (1, DMF?=?N,N-dimethylformamide) and {[Co(L)(H₂O)₂]?·?0.5CH₃OH?·?1.5H₂O} _n (2) under different conditions. The complexes were characterized by IR, elemental, and thermogravimetric analyses, powder and single crystal X-ray diffraction. In 1 each L^2? links four Cd^II to form a 3-D framework, while in 2 each L^2? connects three metals to form a 2-D layer structure, which is further connected together by hydrogen bonds to form a 3-D architecture. The thermal stability of the complexes and the photoluminescence of 1 were investigated.