Triphenylphosphine-supported synthesis of two-dimensional silver(I) complex with (1,3,4-thiadiazole-2,5-diyldithio)diacetic acid

The reaction of dicarboxylate ligand, (1,3,4-thiadiazole-2,5-diyldithio)diacetic acid (H₂tdza) with silver(I) acetate and triphenylphosphine (PPh₃) facilitate the formation of complex [Ag₂(tdza)(PPh₃)₂]_n (1). The complex was characterized by elemental analysis, FT-IR spectroscopy, ¹H-NMR, ¹³C-NMR and ³¹P-NMR spectroscopy, and single crystal X-ray diffraction. Structural analysis revealed that complex 1 has a 2D topologically promising architecture as a result from the formation of 26-membered cyclic ring. The tdza2^? ligand in 1 displays unprecedented µ₄-bridging mode which is also the first example for this ligand. The interdigitating arrangement and π-π stacking between 2D arrays stabilized the formation of complex 1.     

Synthesis,characterization and crystal structure of a novel three-dimensional supramolecular architecture formed by manganese(II) and pyridine-2,5-dicarboxylic acid

A novel three-dimensional supramolecular compound formed by Mn(II) and pyridine-2,5-dicarboxylic acid of formula [Mn(Pydc)₂(H₂O)₂] (Pydc?=?pyridine-2,5-dicarboxylic acid) has been synthesized and characterized by elemental analyses, IR, electronic spectra, thermogravimetric analysis and X-ray diffraction techniques. The X-ray structure shows that the central Mn(II) ion is coordinated by two water molecules and two chelated Pydc ligands. Water molecules coordinate with Mn(II) ions in the cis mode. Intermolecular hydrogen bonds play an important role in stabilization of the lattice and construction of the supramolecular network.     

Synthesis,crystal structure and magnetic property of a one-dimensional copper(II) complex with 2,5-dimethylpyrazine-1,4-dioxide as bridging ligand

A one-dimensional polynuclear copper(II) complex [Cu(μ_1,6-dmpzdo)(SCN)₂] _n (where dmpzdo?=?2,5-dimethylpyrazine-1,4-dioxide) has been synthesized and its crystal structure determined by X-ray crystallography. The coordination geometry of Cu(II) atom is a square plane and each Cu(II) ion is connected by two μ_1,6-dmpzdo bridging ligands, leading to the formation of a one-dimensional chain. ESR spectra indicate magnetic coupling between the bridged Cu(II) ions. The fitting of the variable-temperature magnetic susceptibility data (4–300?K) gave 2J?=??68.69?cm^?1.     

Synthesis,crystal structure and anti-ferromagnetic behavior of a two-dimensional manganese(II) complex with 3,6-dinitro-1,2,4,5,-benzenetetracarboxylate anion as bridging ligand

A two-dimensional complex {[Mn₂(DBT)(DMF)₄]·2H₂O}_n (DBT?=?3,6-dinitro-1,2,4,5- benzenetetracarboxylate anion; DMF?=?N,N-dimethylformamide) has been synthesized and its crystal structure determined by X-ray crystallography. The complex crystallizes in a triclinic system and the space group is P 1 with a?=?9.012(5), b?=?9.196(6), c?=?9.910(6)?Å. In the complex there exist two kinds of coordination environments for Mn(II) ions; each DBT coordinates four Mn(II) ions by its four carboxylate groups and in this way a two-dimensional sheet was constructed. The variable-temperature magnetic susceptibility of the complex was measured in the 5–300?K range and the magnetic data indicate that the magnetic interaction between the bridged manganese(II) ions displays an anti-ferromagnetic coupling.     

Activated carbon cloth filled pipette tip for solid phase extraction of nickel(II), lead(II), cadmium(II), copper(II) and cobalt(II) as 1,3,4-thiadiazole-2,5-dithiol chelates for ultra-trace detection by FAAS

A solid phase extraction method is established for preconcentration of nickel, lead, cadmium, copper and cobalt using pipette tip solid phase extraction. The presented process was dependent on chelation of analytes with 1,3,4-thiadiazole-2,5-dithiol, then allowing the solution to flow through an activated carbon cloth packed pipette tip. The adsorbed metal chelates on the surface of activated carbon cloth were eluted by 5 mL of 3 M HNO₃. The concentrations of nickel, lead, cadmium, copper and cobalt were detected using a flame atomic absorption spectrometer (FAAS). The pipette tip solid phase extraction exhibit a preconcentration factor of 120. The limit of detection values were 2.7, 1.7, 1.3, 2.0 and 2.9 µg L^?1 for Ni(II), Pb(II), Cd(II), Cu(II) and Co(II), respectively. Validation of the method was checked by the analysis of TMDA-53.3 and TMDA-64.2 certified reference materials. The method was successfully applied for water and fertiliser samples.     

Covalently bonded infinite zigzag chain structure in a novel Zn(II) complex of 2,5-dihydroxy-1,6-benzenedicarboxylic acid

Reaction of the disodium salt of 2,5-dihydroxy-1,6-benzenedicarboxylic acid (DHBDC) and zinc sulfate in aqueous solution at room temperature yields complex [Zn(H₂O)₂(DHBDC)]_n. The coordination tetrahedron around Zn center exhibits a highly irregular geometry, two carboxylato oxygen atom and two water–ligand oxygen atoms occupying the coordination sites. Structural analyses of this complex reveal that the individual zero-dimensional units (0D) are covalently linked through their metal ends, forming infinite 1D zigzag chains. These chains, in turn, are engaged in 2D hydrogen bonding, resulting in a 3D supramolecular architecture.     

Structures of substituted di-aryl-1,3,4-oxadiazole derivatives: 2,5-bis(pyridyl)- and 2,5-bis(aminophenyl)-substitution

Crystal structures of four different di-aryl-1,3,4-oxadiazole compounds (aryl = 2-pyridyl-, 3-pyridyl-, 2-aminophenyl-, 3-aminophenyl-) are determined. Crystallization of di(2-pyridyl)-1,3,4-oxadiazole yielded monoclinic and triclinic polymorphs. The structures are characterized by the occurrence of π–π interactions. Additionally, in case of the aminophenyl compounds intra- as well as intermolecular hydrogen bonds are found that influence the packing motif as well. Since these molecules are often used as ligands in metal–organic complexes similarities and differences of the molecular conformation between the molecules in the pure crystals and that of the ligands in the complexes are discussed.     

2,5-二苯腙基-1,3,4-噻二唑类化合物的合成及抗腐蚀性能研究

以2,5-二巯基-1,3,4-噻二唑为原料, 与水合肼反应制得2,5-二肼基-1,3,4-噻二唑, 再将其与取代苯甲醛缩合, 得到了6种新的2,5-二苯腙基-1,3,4-噻二唑类化合物, 其结构经元素分析、红外、¹H NMR及质谱等方法所证实. 6种噻二唑衍生物对喷气燃料银片腐蚀有一定的抑制作用.     

Spectroscopic,thermal and structural studies of a new mercury(II) one-dimensional coordination polymer, [Hg(3-bpo)2(SCN)2], 3-bpo = 2,5- bis (3-pyridyl)-1,3,4-oxadiazole

A new mercury(II)-organic polymeric complex generated from 2,5-bis(3-pyridyl)-1,3,4-oxadiazole (3-bpo) as an angular dipyridyl derivative ligand, [Hg(3-bpo)₂(SCN)₂], was prepared from reactions of ligand 3-bpo with mercury(II) thiocyanate. The compound was characterized by elemental analysis, IR-, ¹H NMR-, ¹³C NMR-spectroscopy and structurally determined by X-ray single crystal diffraction. The thermal stability of [Hg(3-bpo)₂(SCN)₂] was studied by thermal gravimetric (TG) and differential thermal analyses (DTA).     

Synthesis and characterization of a zinc(II) complex of 1,3-bis(1-benzylbenzimidazol-2-yl)-2-oxopropane

A ligand 1,3-bis(1-benzylbenzimidazol-2-yl)-2-oxopropane (Bobb) and the zinc(II) complex, [Zn(Bobb)₂](picrate)₂ · 2DMF, were synthesized and characterized by elemental analyses, electrical conductivities, IR, and UV. The crystal structures of the ligand and the zinc complex have been determined by single crystal X-ray diffraction. The ligand displays a V-shaped configuration and the Zn(II) cation is six-coordinate by four nitrogens and two oxygens from Bobb. The N₄O₂ donor set is a distorted octahedron.     

Synthesis and characterization of a Cu(II) complex of 2-benzylmercapto-5-methyl-1,3,4-thiadiazole (C10H10N2S2)

A Cu(II) complex of 2-benzylmercapto-5-methyl-1,3,4-thiadiazole was synthesized and characterized. The crystal structure of the copper complex and the free ligand were determined by single-crystal X-ray diffraction at room temperature: {[Cu(C₁₀H₁₀N₂S₂)₂(Cl)₂], P 1 triclinic, a = 8.1450(2) Å, b = 8.1690(2) Å, c = 10.8180(3) Å, α = 97.4040(12)°, β = 101.6270(11)°, γ = 116.1431(14)°; C₁₀H₁₀N₂S₂ ligand, Pbca orthorhombic, a = 8.7938(7) Å, b = 9.6491(7) Å, c = 25.3552(18) Å}. The metal complex framework consists of discrete units that provide crystalline stability through a network of van der Waals contacts. The Cu(II) is coordinated by two chloride ions and two 2-benzylmercapto-5-methyl-1,3,4-thiadiazole monodentate ligands showing a distorted square planar configuration. Both thiadiazole ligands coordinate through the N atom bonded to the benzylthio substituted C atom.

The FTIR spectroscopic data are consistent with this structural model. Analysis of the magnetic susceptibility from 5 K to room temperature indicates the presence of paramagnetic Cu(II), confirmed by the EPR spectrum.     

N-(5-对-氯苯氧甲基-1,3,4-噻二唑-2-基)-S-(4-苯基-5-苯氧甲基-1,2,4-三唑-3-基)乙酰胺的合成与表征

取代苯氧乙酰肼(1a～1c)与异硫氰酸芳基酯(2a～2d)反应得到酰基硫脲类化合物(3a～3l),经碱合环得到4-苯基-5-苯氧甲基-1,2,4-三唑-3-硫酮(4a～4l),然后再与N-(5-对氯苯氧甲基-1,3,4-噻二唑-2-基)氯乙酰胺(6)反应合成了化合物N-(5-对氯苯氧甲基-1,3,4-噻二唑-2-基)-S-(4-苯基-5-苯氧甲基-1,2,4-三唑-3-基)乙酰胺(7a～7l)。所有化合物结构经元素分析、IR、1HNMR和MS确证。测定了化合物4e的晶体结构,其属于三斜晶系,P-1空间群,晶胞参数a=7.123(4),b=9.786(5),c=11.543(6),α=70.846(7)°,β=80.089(9)°,γ=89.922(11)°,V=747.5(7)3,Dc=1.345g/cm3,Z=2,F(000)=310,μ=0.218mm-1,R=0.0913,wR=0.2622     

Synthesis,crystal structure,and luminescence of a quaternary binuclear europium complex [Eu2(phth)2(Hphth)2(phen)2(H2O)4]

A quaternary binuclear europium complex [Eu₂(phth)₂(Hphth)₂(phen)₂(H₂O)₄] (H₂phth?=?phthalic acid, phen?=?1,10-phenanthroline) has been synthesized. The structure was determined by X-ray crystallography which reveals that it is binuclear with each europium nine-coordinate. Intermolecular hydrogen bonds link the complex units to form a 3D supermolecular network. Its properties have been studied by means of luminescence spectrum and thermal analysis. Fluorescence spectra show that the complex exhibits strong red emission.     

Synthesis and spectral and structural characterization of a bridging chloropicolinatocopper(II) complex,Cu(C5H4NCOO)Cl

Summary The title complex of copper(II) chloride with picolinic acid was prepared and characterized by spectroscopic and X-ray crystallographic methods. The complex, Cu(C₅H₄NCOO)Cl, crystallizes tetragonal, space group P4₂/n (No. 86),a=976.4(1),c=1499.6(4) pm,N=8;R _w=0.048 for 543 observed MoK diffractometer data. In the structure of the complex two -chloro bridges form only slightly bent Cu₂Cl₂ rings [Cu-Cl=224.2(4) and 275.6(4) pm] with Cu...Cu separation of 359.4(2) pm and Cl...Cl separation of 348.7(5) pm. These edge-sharing copper coordination polyhedra are further linked via the N and O donor atoms of the picolinato anions at Cu-N distances of 199.6(12) pm and Cu-O bond lengths of 195.7(8) and 200.6(10) pm, to form a two-dimensional layer structure in which these layers are arranged along theab plane. Each picolinate anion functions as a tetra-dentate ligand: N(1) and O(2) are coordinated to the same Cu(II) center whereas O(1) is bonded to a neighbouring Cu(II) center. O(2) is further bonded to the latter Cu(II) center at a long Cu-O distance of 256.5(8) pm. The electronic, infrared and Raman spectra of the solid complex are reported and discussed.

---

Synthese und spektroskopische und strukturelle Charakterisierung eines verbrückten Chloropicolinatokupfer(II) Komplexes, Cu(C₅H₄NCOO)Cl

Zusammenfassung Der Titelkomplex aus Kupfer(II)chlorid und Picolinsäure wurde dargestellt und mit spektroskopischen und Röntgen-Einkristall-Methoden charakterisiert. Cu(C₅H₄NCOO)Cl kristallisiert tetragonal, Raumgruppe P4₂/n (No. 86),a=976.4(1),c=1499.6(4) pm,N=8;R _w=0.048 für 543 beobachtete Mok-Diffraktometerdaten. In der Kristallstruktur bilden zwei -chloro-Brücken nur wenig gewinkelte Cu₂Cl₂-Ringe aus [Cu-Cl=224.2(4) und 275.6(4) pm], mit Cu...Cu Abständen von 359.4(2) pm und Cl...Cl Abständen von 348.7(5) pm. Die kantenverknüpften Koordinationspolyeder der Kupferatome sind in Richtung derab-Ebene über die N- und O-Donoratome der Picolinat-Anionen [mit Cu-N Abständen von 199.6(12) pm und Cu-O Abständen von 195.7(8) und 200.6(10) pm] zu einer zweidimensionalen Schichtstruktur verknüpft. Jedes Picolinat-Anion fungiert als vierzähniger Ligand: N(1) und O(2) sind zum selben Cu(II)-Zentrum gebunden; O(1) ist zum benachbarten Cu(II)-Zentrum koordiniert, zu dem O(2) einen langen Cu-O-Abstand von 256.5(8) pm ausbildet. Die elektronischen, Infrarot- und Raman-Spektren des Festkörper-Komplexes werden berichtet und diskutiert.

     

Synthesis,characterization, and biological activity of a Cu(I) complex with 2-(9H-carbazol-9-yl) acetic acid

A new dicopper(I) complex with 2-(9H-carbazol-9-yl) acetic acid (HL) of the formula [Cu₂(dppm)₂L(NO₃)(CH₃OH)] [dppm = bis(diphenylphosphino)methane] was prepared. The complex was structurally characterized by IR, ¹H NMR spectra, and elemental analysis. Single crystal X-ray crystallography revealed that this complex is monoclinic, space group P2₁/c, with a = 13.6552(17) Å, b = 23.123(2) Å, c = 19.257(2) Å, α = γ = 90.00°, β = 106.860(2)°, V = 5818.8(11) ų, Z = 4, D _Calcd = 1.386 mg m^?3, F(000) = 2512, goodness-of-fit = 1.015. The complex was also tested in vitro for its cytotoxic activity using human hepatocellular carcinoma cell line (BEL-7402) and human hepatocellular liver carcinoma cell line (Hep-G2); 5-Fluorouracil was used as a positive control substance. The results indicated that the complex exhibited good cytotoxic activity against both human tumor cell lines.     

Design and synthesis of new ethylenediamine or propylenediamine diacetic acid derivatives for Re(I) organometallic chemistry

A general synthetic approach for a novel range of bifunctional chelating agent (BCA) for the ‘fac-[M(CO)₃]⁺‘ core (M=^99mTc, ⁹⁹Tc or Re) has been developed. The strategy includes the facile preparation of these tridentate ligands possessing a tertiary amine bearing two carboxylic acid functions as coordinating site and an aromatic amino group for coupling to a biovector. First complexation study has shown that these compounds act exclusively as tridentate ligands (via the two acids and the tertiary amine functions). The convenient synthesis of these new ligands coupled with their high affinity for Re(I) make them quite promising for biomedical applications.     

Synthesis,characterization, and antibacterial activity of a manganese(II) complex of triaryltriazole

A manganese(II) complex of 4-(4-methylphenyl)-3,5-bis(2-pyridyl)-4H-1,2,4-triazole (MBPT) was synthesized and characterized by X-ray crystallography. [Mn(MBPT)₂(H₂O)₂](ClO₄)₂?·?4H₂O is a divalent mononuclear manganese(II) complex with manganese coordinated to four nitrogens from two triazole ligands and two oxygens from two water molecules in a slightly distorted octahedral geometry. The complex and ligand were tested in vitro for their antibacterial activities. The title complex showed a wide range of bactericidal activities.     

Synthesis and Crystal Structure of 2,5-Di- （pyridin-3-yl）-1,3,4-oxadiazolendium Nitrate

In order to continue our studies on the synthesis, properties and coordination of s-tetrazine, 3,6-di-(pyridin-3-yl)-s-tetrazine (II, 3-dptz) was synthesized and characterized by 1H- NMR, MS and IR spectra. And the coordination reaction of 3-dptz with nitrate of Cu(II) was studied. 3-dptz reacting with CuII salt [Cu(NO3)2·2H2O] generates a new salt, nitrate of 2,5-di-(pyridin-3- yl)-1,3,4-oxadiazolene (III). III was determined by IR spectra and single-crystal X-ray diffraction to give the following crystal data: space group P21/c, a = 4.9112(1), b = 8.4101(3), c = 29.499(1) , β = 93.266(2)o, V = 1216.44(7) nm3, Mr = 287.24, Z = 4, Dc = 1.568 g/cm3,μ= 0.122 mm-1, F(000) = 592, R = 0.0430 and wR = 0.1240. The results show that III is composed of one cation and one nitrate anion. The cation consists of one H+ and one 2,5-di-(pyridin-3-yl)-1,3,4-oxadiazol molecule, with the former being attached to the latter via electrovalent bond with N3 atom. And the O(42) atom in the nitrate anion is disordered. Intra- and intermolecular H-bonds are observed in the crystal of the title compound. The mechanism of metal-assisted decomposition was also discussed briefly.     

Syntheses and crystal structures of two Cu(II) complexes based on a fused heterocycle ligand containing 1,3,4-thiadiazole

By refluxing a mixture of CuCl₂ and 3-methyl-6-phenyl-[1,2,4]-triazolo[3,4-b][1,3,4]thiadiazole (TRTZ) with addition of acetic acid and KSCN, respectively, the complexes [Cu(TRTZ)₂(OAc)₂(H₂O)]?·?1.5H₂O (1) and [Cu(TRTZ)₂(SCN)₂(H₂O)₂]?·?2DMF (2) were obtained. Single-crystal structure of both complexes was determined and their thermal behaviour and IR spectra examined.