Synthesis,crystal structures,and characterization of copper(II) carboxylate complexes incorporating 1,10-phenanthroline and bipyridine

A series of Cu(II) carboxylate complexes (carboxylate?=?2-fluorobenzoic acid (2-HFBA) or 4-fluorobenzoic acid (4-HFBA)) containing either one chelating 1,10-phenanthroline (phen) or 2,2′-bipyridine (bipy) have been synthesized and characterized by single-crystal X-ray diffraction, IR spectroscopy, and thermal analyses. In [Cu(bipy)(H₂O)(2-FBA)₂] (1), [Cu(bipy)(H₂O)(4-FBA)₂] (3), and [Cu(phen)(H₂O)(2-FBA)₂] (4), Cu is five-coordinate in a square pyramidal geometry and four-coordinate in [Cu(phen)(2-FBA)₂] (2). The four complexes are extended into 1-D chains through hydrogen-bonding and π?···?π interactions in 1 and 4, only hydrogen-bonding in 2, and π?···?π interactions in 3. These contacts lead to aggregation and supramolecular self-assembly.     

Synthesis,characterization, DNA-binding,and antioxidant activities of four copper(II) complexes containing N-(3-hydroxybenzyl)-amino amide ligands

Four new substituted amino acid ligands, N-(3-hydroxybenzyl)-glycine acid (HL₁), N-(3-hydroxybenzyl)-alanine acid (HL₂), N-(3-hydroxybenzyl)-phenylalanine acid (HL₃), and N-(3-hydroxybenzyl)-leucine acid (HL₄), were synthesized and characterized on the basis of ¹H NMR, IR, ESI-MS, and elemental analyses. The crystal structures of their copper(II) complexes [Cu(L₁)₂]·2H₂O (1), [Cu(L₂)₂(H₂O)] (2), [Cu(L₃)₂(CH₃OH)] (3), and [Cu(L₄)₂(H₂O)]·H₂O (4) were determined by X-ray diffraction analysis. The ligands coordinate with copper(II) through secondary amine and carboxylate in all complexes. In 2, 3, and 4, additional water or methanol coordinates, completing a distorted tetragonal pyramidal coordination geometry around copper. Fluorescence titration spectra, electronic absorption titration spectra, and EB displacement indicate that all the complexes bind to CT-DNA. Intrinsic binding constants of the copper(II) complexes with CT-DNA are 1.32?×?10^6?M^?1, 4.32?×?10^5?M^?1, 5.00?×?10^5?M^?1, and 5.70?×?10^4?M^?1 for 1, 2, 3, and 4, respectively. Antioxidant activities of the compounds have been investigated by spectrophotometric measurements. The results show that the Cu(II) complexes have similar superoxide dismutase activity to that of native Cu, Zn-SOD.     

Metal complexes with N-(trifluoromethylbenzyl)iminodiacetate chelators (x-3F ligands). Part I. Copper(II) chelates of p-3F,m-3F,and o-3F with or without imidazole-like ligands

Eight Cu(II) complexes with N-(p-, m- or o-trifluoromethylbenzyl)iminodiacetate chelators (x-3F ligands) have been synthesized to promote C–F/H interligand interactions involving the F₃C-group: {[Cu(μ₂-p-3F)(H₂O)]·3H₂O]}_n (1), [Cu(m-3F)(H₂O)₂] (2), [Cu(p-3F)(Him)(H₂O)] (3), [Cu(m-3F)(Him)(H₂O)] (4), [Cu(o-3F)(Him)(H₂O)] (5), [Cu₂(p-3F)₂(H5Meim)₂(H₂O)₂] (6), [Cu(m-3F)(H5Meim)(H₂O)] (7), and [Cu(o-3F)(H5Meim)(H₂O)] (8) [Him and H5Meim = imidazole and the “remote” tautomer 5-methylimidazole, respectively]. The compounds were studied by single-crystal X-ray diffraction, FT-IR, electronic spectra and coupled thermogravimetric + FT-IR methods. The conformation of the iminodiacetate chelating moiety (IDA group) is fac-NO + O(apical) in 1 and mer-NO₂ in 2–8. The fac-IDA conformation observed in 1 is related to its polymeric structure and the coordination of a O’-carboxylate donor, from an adjacent complex unit, trans to the Cu–N(IDA) bond. The mer-IDA conformation in 2 is in agreement with similar compounds with an aqua ligand trans to the corresponding Cu–N(IDA) bond. As expected, the ternary complexes 3–8 feature a mer-IDA conformation. Some of the studied complexes exhibit disorder in the –CF₃ group and C–H?F interligand interactions along with conventional N–H?O and O–H?O interactions. The thermal decomposition of all studied compounds under air flow produces variable amounts of trifluorotoluene.     

UO22+-polycarboxylate heterometallic complexes: structure,spectra, and photocatalytic properties

[Cu₂(UO₂)₄(suc)₄(pac)₄] (1), [(Cu(H₂O)₂)(4,4′-bipy)₂][(UO₂)₂(H₂O)₂(Hca)₂]·3H₂O (2), and [(Cu(H₂O)₂)(UO₂)(bta)]·4H₂O (3) were synthesized by the reaction of succinic acid and 3-pyridinecarboxylic acid, citric acid and 4,4′-bipyridine, or 1,2,4,5-benzenetetracarboxylic acid ligands with Cu(NO₃)₂·3H₂O and UO₂(CH₃COO)₂·2H₂O. The complexes were characterized by IR and UV–vis spectroscopy, powder X-ray diffraction, single-crystal X-ray diffraction, and photoluminescence spectroscopy. Photocatalytic activities of the complexes were also investigated.     

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,structures, and catalytic oxidation of three aqua-coordinated and oxo-bridged diruthenium(III) complexes with sulfobenzoate and 2,2′-bipyridine

Three new diruthenium(III) complexes, [Ru₂O(2-sb)₂(2,2′-bipy)₂(H₂O)₂]·2.5H₂O (1), [Ru₂O(3-sb)₂(2,2′-bipy)₂(H₂O)₂]·9H₂O (2), and [Ru₂O (4-sb)₂(2,2′-bipy)₂(H₂O)₂]·9H₂O (3), where sb^2? is sulfobenzoate dianion and 2,2′-bipy is 2,2′-bipyridine, were synthesized using hydrothermal methods and characterized by IR, elemental analysis, thermogravimetric analysis, UV–vis, and fluorescence spectra. The single crystal X-ray analysis showed that each of these complexes has a dinuclear core stabilized by two bridging carboxylates and one bridging O^2?. Variable sb^2? ligands (2-sb, 3-sb, and 4-sb) in these complexes lead to diverse electronic spectroscopic behavior. The efficiency of activating methyl phenyl sulfide oxidation utilizing H₂O₂ in 3 equiv. was studied at 23?±?2?°C. The effect of the amount of catalyst and solvents on activities was investigated. Under optimized reaction conditions, the major product was sulfoxide. Complex 1 gave significant conversion of 100 and 98% selectivity for sulfoxide after 4?h.     

Syntheses of crystal structures and in vitro cytotoxic activities of new copper(II) complexes of pyridine-2,6-dicarboxylate

[Cu(pydc)(im)]_n (1), [Cu(pydc)(mim)₃]?2H₂O (2), [Cu(pydc)(ampy)(H₂O)]?H₂O (3), and [Cu(pydc)(phen)][Cu(Hpydc)₂] (4) (H₂pydc = 2,6-pyridinedicarboxylic acid or dipicolinic acid, im = imidazole, mim = 2-methylimidazole, ampy = 2-amino-4-methylpyridine, and phen = 1,10-phenanthroline) were synthesized and characterized by elemental analysis, spectroscopic measurements (UV–vis and IR spectra) and single crystal X-ray diffraction. Complexes 1, 2 and 3 were studied by thermogravimetric analysis from ambient temperature to 1100 K under nitrogen and thermal stabilities were investigated. The effects of complexes on proliferation of fibrosarcoma cells were investigated using the Quick Cell Proliferation Assay. The cell viability changes depend on the concentrations and type of complexes. According to cell proliferation/viability data, 4 was determined to be the most cytotoxic.     

Studies on DNA binding behavior of biologically active Cu(II) complexes of Schiff bases containing acyl pyrazolones and 2-ethanolamine

Pyrazolone derivatives (Z)-4-((2-hydroxyethylimino)(p-tolyl)methyl)-3-methyl-1-phenyl-1H-pyrazol-5(4H)-one [PMP-EA] (1), (Z)-1-(3-chlorophenyl)-4-((2-hydroxyethylimino)(p-tolyl)methyl)-3-methyl-1H-pyrazol-5(4H)-one [MCPMP-EA] (2), and (Z)-4-((2-hydroxyethylimino)(p-tolyl)methyl)-3-methyl-1-p-tolyl-1H-pyrazol-5(4H)-one [PTPMP-EA] (3) have been synthesized and characterized. The molecular geometry of 2 has been determined by single-crystal X-ray study. These ligands exist in amine-one tautomeric form in the solid state. Three copper(II) complexes, [Cu(PMP-EA)(H₂O)₂] (4), [Cu(MCPMP-EA)(H₂O)₂] (5), and [Cu(PTPMP-EA)(H₂O)₂] (6), respectively, have been synthesized using these ligands and characterized by microanalytical data, molar conductivity, IR, UV–Visible, FAB-Mass, magnetic measurement, TG-DTA studies, and ESR spectral studies; Cu(II) is five-coordinated with [ML(H₂O)₂] composition. The interaction of the complexes with CT-DNA (calfthymus) was investigated using different methods. The results suggest that the copper complexes bind to DNA via intercalation and can quench the fluorescence intensity of EB bound to DNA.     

Syntheses,crystal structures and characterization of divalent transition metal sulfonate complexes with O-phenanthroline

Two new complexes, [Zn(phen)₂(H₂O)₂]2L·H₂O (1) and [Cu(phen)(L)(H₂O)₂]L·3H₂O (2), where HL?= 4-aminobenzenesulfonic acid and phen = o-phenanthroline, have been synthesized and their crystal structures determined by X-ray diffraction. In the complexes the Cu(II) and Zn(II) atoms revealed two different coordination environments. Complex 1 consists of a cation [Zn(phen)₂(H₂O)₂]²⁺, in which Zn(II) is six-coordinated by four nitrogen atoms from two o-phenanthroline molecules and by two water molecules. Complex 2 has two crystallographically unique Cu(II) ions, where Cu(II) ion is five-coordinate with two nitrogen atoms of o-phenanthroline, two water molecules and one sulfonate oxygen atom. The electrochemical behavior and FT-IR of the two compounds have also been studied in detail.     

Supramolecular networks constructed by cationic copper(II) complexes incorporating hybrid water–anionic polymeric assemblies

Two complexes, [Cu₂(TFSA)(2,2′-bpy)₄]?·?TFSA?·?8H₂O (1) and {[Cu(4,4′-bpy)(H₂O)₂]?·?TFSA?·?6H₂O} _n (2) (H₂TFSA?=?tetrafluorosuccinic acid, 2,2′-bpy?=?2,2′-bipyridine, and 4,4′-bpy?=?4,4′-bipyridine), have been synthesized and structurally characterized by X-ray structural analyses. Complex 1 is a binuclear molecule bridged by TFSA ligands; 2 is a 1-D chain bridged by 4,4′-bpy ligands. The asymmetric units of the two complexes are composed of cationic complexes [Cu₂(TFSA)(2,2′-bpy)₄]²⁺ (1) and [Cu(4,4′-bpy)(H₂O)₂]²⁺ (2), free TFSA anion, and independent crystallization water molecules. A unique 2-D hybrid water–TFSA anionic layer by linkage of {[(H₂O)₈(TFSA)]^2?} _n fragments consisting of 1-D T6(0)A2 water tape and TFSA anionic units by hydrogen bonds in 1 was observed. Unique 2-D hybrid water–TFSA anionic layer generated by the linkage of {[(H₂O)₆(TFSA)]^2?} _n fragments consisting of cyclic water tetramers with appended water molecules and TFSA anionic units, and 1-D metal–water tape [Cu–H₂O?···?(H₂O)₆?···?H₂O^?] _n in 2 were found. 3-D supramolecular networks of the two complexes consist of cationic complexes and water–TFSA anionic assemblies connected by hydrogen bonds.     

Three Keggin-based complexes modified by an asymmetric ligand: structures,electrochemical, photocatalytic and fluorescence sensing properties

By using an asymmetric ligand with triazole and imidazole groups, three Keggin-based complexes were obtained, [Cu(HMET)₄(H₂O)₂](PMo₁₂O₄₀)₂·2H₂O (1), [Cu₃(HMET)₄Cl₂(H₂O)₂(XM₁₂O₄₀)₂]·4H₂O (X?=?Si, M?=?W 2, X?=?Ge, M?=?Mo 3) (MET?=?4-(2-imidazol-1-yl-ethyl)-4H-[1,3,4]triazole). Complex 1 contains discrete Keggin anions and mono-nuclear [Cu(MET)₄(H₂O)₂]²⁺ clusters. Complexes 2 and 3 are isostructural with tri-nuclear Cu clusters linked by Keggin anions to construct a 1D chain. The 1- to 3-CPEs show electrocatalytic properties and can also act as nitrite amperometric sensors. Complexes 1–3 exhibit photocatalytic activities for degradation of MB. Complexes 1–?3 own fluorescence sensing properties for detecting Hg²⁺ ions.

Graphical abstract

By using an asymmetric ligand three POM-based complexes were constructed. The 1– to 3–CPEs exhibit good electrocatalytic activities and can be used as nitrite amperometric sensors. The title complexes show good photocatalytic activities for degradation of MB. Moreover, complexes 1–3 can act as fluorescence sensors to selectively detect Hg²⁺.

     

Synthesis,characterization, thermal,and antimicrobial studies of binuclear metal complexes of sulfa-guanidine Schiff bases

A series of metal complexes of Schiff bases derived from condensation of sulfa-guanidine with 1-benzoylacetone (H₂L¹), 2-hydroxybenzophenol (H₂L²), dibenzoylmethane (H₂L³), 5-methylisatine (H₂L⁴), and 1-methylisatine (H₂L⁵) have been synthesized. The complexes are characterized by elemental analysis, molar conductance, magnetic moment measurements, IR, UV–Vis, ¹H NMR, and ESR spectra, as well as thermogravimetric analysis. The low molar conductance values indicate the complexes are nonelectrolytes. IR and ¹H NMR spectra show that H₂L¹–H₂L⁵ are coordinated to metal ions by two bidentate centers. Mn(II), Co(II), Ni(II), and Cu(II) complexes display paramagnetic behavior, whereas the Zn(II)-complex was diamagnetic. All studies confirm the formation of an octahedral geometry for [Cu₂L¹(AcO)₂(H₂O)₆] · 3H₂O (1), [Mn₂L⁴(AcO)₂(H₂O)₆] · 2H₂O (6), [Ni₂L⁴(AcO)₂(H₂O)₆] · 2H₂O (8), a tetrahedral geometry for [Cu₂L²(AcO)₂(H₂O)₂] (2), [Cu₂(L⁴)₂] (4), [Co₂(L⁴)₂] · 2H₂O (7) and [ZnHL⁴(AcO)(H₂O)] · 2H₂O (9) and a trigonal bipyramid geometry for [Cu₂L³(AcO)₂(H₂O)₄] (3) and [Cu₂HL⁵(AcO)₃(H₂O)₃] · H₂O (5). H₂L⁴ was most effective on Gram negative, Gram positive bacteria, and fungi (diameters inhibition zone ranged between 10.5–27.5 mm) after 24 and 48 h, respectively. Complex 8 showed moderate antimicrobial activity. Its minimum inhibitory concentration (MIC) against Escherichia coli, Bacillus subtilis, Candida albicans and Aspargllus flavas was 20 mg L^–1. The compound proved to be of moderate toxicity and its LD₅₀ was 20 mg L^–1.     

Syntheses,crystal structures,and properties of various one- dimensional coordination polymers based on macrocyclic metallic tectons and dicarboxylic acid ligand

The reaction of different macrocyclic metallic tectons and dicarboxylic acid ligand yielded six new coordination polymers, namely, {[(NiL¹)(4,4'-Bpdc)] ? DMF ? 2.5H₂O} _n (I), {[(NiL²)(4,4'-Bpdc)] ? DMF ? 2.5H₂O} _n (II), [(NiL³)₂(4,4'-Bpdc)_1.5][(NiL³)(4,4'-Bpdc)] ? ClO₄ ? 28H₂O (III), {[(NiL⁴)(4,4'-Bpdc)] ? 4H₂O} _n (IV), {[(NiL⁵)(4,4'-Tpdc)] ? 5H₂O} _n (V), {[(NiL³)(4,4'-Tpdc)]} _n (VI) (L¹ = 1,4,7,9,12,14-hexaaza-tricyclo[12.2.1.1^4.7]octadecane, L² = 1,3,10,12,15,18-hexaazatetracyclo[16.2.1.1^12.15.0^4.9]docosane, L³ = 11-methyl-1,4,8,10,13,15-hexaaza-tricyclo[13.3.1.1^4.8]icosane, L⁴ = 1,3,10,12,16,19-hexaazate-tracyclo[17.3.1.1.^12.16,0^4.9]tetracosane, L⁵ = 1,4,8,10,13,15-hexaaza-tricyclo[13.3.1.1^4.8]icosane, 4,4'-Bpdc = 4,4'-biphenyldicarboxylic acid and 4,4'-Tpdc = 4,4'-terphenyldicarboxylic acid) (CIF files CCDC nos. 1055545–1055550 for I–VI, respectively). Except for the different conformations of the macrocyclic metallic tectons or dicarboxylic acid ligands, complexes I–VI crystallized under the same environment, however, they exhibit diverse packing mode of infinite 1D coordination polymers, showing macrocyle or dicarboxylic acid ligand regulated self-assemble. The solid states UV-Vis for complexes I–VI also have been investigated.     

In situ synthesis,crystal structures,and luminescence of two new tetrazole complexes

The synthesis, crystal structures, and luminescent properties of two new complexes containing tetrazolyl ligands are described. Refluxing a mixture of fipronil (fipronil = (±)-5-amino-1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-4-[(trifluoromethyl)sulfinyl]-1H-pyrazole-3-carbonitrile), sodium azide, and CuCl₂ in ethanol and water gives complex 1, [M(L)₂](H₂O)₂] ? 2H₂O (HL = (±)-5-amino-1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-4-[(trifluoromethyl)sulfinyl]-1H-pyrazole-3-tetrazole, M = Cu). Hydrothermal reaction of fipronil, sodium azide, and Cd(ClO₄)₂ in the presence of water and ethanol (Demko–Sharpless tetrazole synthesis) yields 2, [M(L)₂](H₂O)₂] ? 2H₂O (M = Cd). The metals in both complexes are six coordinate from two water molecules, two nitrogens from different tetrazolyl groups, and two nitrogens from pyrazolyl groups. Photoluminescence studies reveal that 2 exhibits strong blue fluorescent emission at λ _max = 451 nm in solid state at room temperature.     

Three new polyoxoniobates constructed from Lindqvist-type hexaniobate and copper–amine complexes

Three new polyoxoniobates constructed from Lindqvist-type [Nb₆O₁₉]^8? and copper–amine complexes, [Cu(1,2-dap)₂]{[Cu(1,2-dap)₂]₂[Nb₆O₁₉H₂]}?·?10H₂O (1), [Cu(1,3-dap)₂]₂{[Cu(1,3-dap)]₂[Nb₆O₁₉]}?·?10H₂O (2), and [Cu(en)₂]_0.5{[Cu(en)₂]₂[Nb₆O₁₉H₃]}?·?12H₂O (3) (1,2-dap?=?1,2-diaminopropane, 1,3-dap?=?1,3-diaminopropane, and en?=?ethylenediamine), have been synthesized and characterized by elemental analyses, infrared, powder X-ray diffraction, thermogravimetric analysis, X-ray photoelectron spectrum, and single-crystal X-ray diffraction. Compounds 1–3 exhibit bisupporting hexaniobate cluster structure, each with a [Nb₆O₁₉]^8? cluster decorated by two copper–amine complexes. In 1, adjacent bisupporting clusters are connected with one [Cu(1,2-dap)₂]²⁺ fragment via Cu?···?O weak interactions to generate a 1-D supramolecular chain structure. In contrast to 1, each bisupporting cluster in 2 is linked to another four neighboring ones through four [Cu(1,3-dap)₂]²⁺ fragments by Cu?···?O weak interactions to yield a 2-D supramolecular network. Different from 1 and 2, no detected interaction was found between bisupporting cluster and [Cu(en)₂]²⁺ in 3, the [Cu(en)₂]²⁺ fragment merely acts as an isolated countercation.     

Syntheses,crystal structures,and properties of four new coordination compounds of transition metals and imidazoledicarboxylic acid derivatives

Four new transition metal coordination complexes, [Cd(H₂pimdc)₂(H₂O)₂]?·?4H₂O (1), [Zn(H₂pimdc)₂(H₂O)₂]₂?·?7H₂O (2), and [M(H₂pimdc)₂] (M?=?Cu (3) or Ni (4), H₂pimdc^??=?2-propyl-4,5-imidazoledicarboxylate), have been prepared by conventional synthesis and characterized by elemental analyses, IR, TG, and single-crystal X-ray diffraction. H₂pimdc^? is a bidentate chelating ligand in 1 and 2, leading to 3-D supramolecular structures through hydrogen bonds. However, H₂pimdc^? is a tridentate chelating-bridge ligand in 3 and 4, which exhibit 2-D layer structures. Thermal properties and photoluminescence spectra of 1–4 were measured.     

Syntheses,characterizations and SOD-like activities of ternary copper(II) complexes with 1,10-phenanthroline and L- α -amino acids

Three new complexes, [Cu(phen)(L-argH⁺)Cl]Cl?·?2.5H₂O (1), [Cu(phen)(L-leu)(H₂O)]Cl?·2.5H₂O (2) and [Cu(phen)(L-met)(H₂O)]Cl?·?2H₂O (3), where phen?=?1,10-phenanthroline, L-arg?=?L-argininate, L-leu?=?L-leucinate, and L-met?=?L-methioninate, were synthesized and characterized by elemental analysis, molar conductivity, IR and UV-Vis spectroscopies. Complex 1 was structurally characterized by single-crystal X-ray diffraction. The superoxide dismutase (SOD)-like activities of the three complexes were determined by the improved NBT method. The results show that the complexes have high superoxide dismutase-like activities and may act as good mimics for superoxide dismutases.     

Syntheses and structural characterization of inorganic–organic hybrid solids of bis-imidazolium chlorocadmate complexes

Six organic–inorganic complexes derived from bis-imidazole derivatives ([(H₂L1)(CdCl₃ ? H₂O)₂] (1), L1 = 1-(3-(1H-benzimidazol-1-yl)propyl)-1H-benzimidazole; [(H₂L2)CdCl₄] (2), L2 = 1,1′-bis(benzimidazolyl)methane; [(H₂L3)CdCl₄] (3), L3 = 1-(2-(1H-benzimidazol-1-yl)ethyl)-1H-benzimidazole; [(H₂L4)₄(CdCl₄)₄] ? 13H₂O (4), L4 = 1,5-bis(1-benzimidazolyl)-3-oxapentane; [(H₂L5)CdCl₄] (5), L5 = 1-(4-(1H-benzimidazol-1-yl)butyl)-1H-benzimidazole; [(H₂L6)(Cd₂Cl₈)_0.5] ? H₂O (6), L6 = 3,6-bis(imidazol-1-yl)pyridazine), and cadmium(II) chloride dihydrate were prepared and characterized by IR, X-ray structure analysis, elemental analysis, and TG analysis. The imidazolyl moieties in all six compounds are essentially planar. X-ray diffraction analysis revealed that complexes 1–6 have 3-D network structures built from hydrogen bonds between imidazolium cations, chlorocadmate anions, and water. The arrangements of the anions and cations in their solid state are dominated not only by the size and symmetry of the imidazolium cations, but also by the different structure types of the chlorocadmate anions as well as the hydrogen-bonded interactions existing in the crystal structures. All of the complexes are thermally stable.     

The syntheses,crystal structure,thermal analysis,and anticancer activities of novel dipicolinate complexes

[Cu(pydc)(eim)₃]?H₂O (1), [Cu(pydc)(4hp)(H₂O)] (2), and [Ni(pydc)(3hp)(H₂O)₂][Cu(pydc)(3hp)(H₂O)₂]?3H₂O (3) (H₂pydc = 2,6-pyridinedicarboxylic acid or dipicolinic acid, eim = 2-ethylimidazole, 4hp = 4-hydroxypyridine, 3hp = 3-hydroxypyridine) were synthesized and characterized by elemental analysis, spectroscopic measurements (UV–vis and IR spectra), and single-crystal X-ray diffraction. Crystal analysis revealed that the complexes extended to 3-D supramolecular networks through intermolecular H-bonding and molecular interactions between the ligand moieties and water molecules. The thermal stabilities of complexes are investigated by thermogravimetry, differential thermogravimetry, and differential thermal analysis techniques. The effects of complexes on the proliferation of HT-1080 fibrosarcoma cells were investigated using the quick cell proliferation assay. The cell viability changes were found to depend on the concentrations and type of complex.