Nickel(II) and copper(II) complexes of allyl 2-(thiophen-2-ylmethylene)hydrazinecarbodithioate: synthesis,X-ray crystal structures,and theoretical study

We report allyl 2-(thiophen-2-ylmethylene)hydrazine-carbodithioate (HL) and its Ni(II) and Cu(II) complexes, [ML₂]. The compounds were fully characterized by elemental analysis, IR, ¹H-NMR, UV-Vis, and molar conductivity. The crystal structure analysis indicates that the metal is four-coordinate square planar and that a parallel stacking of the molecular planes is present in the crystals, with stacking distances of 3.642 and 3.676?Å for the Ni(II) and Cu(II) complexes, respectively. Gas phase DFT computations indicate that the thione tautomeric form of the free ligand is more stable than the thiol form by 14.52?kJ?mol^–1. For HL and ML₂, comparison between the computed and experimental data shows good agreement.     

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.     

Syntheses,structures, and optical properties of two cadmium complexes with chelidamic acid

[Cd₂(C₇H₃NO₅)₂ · 4(H₂O)] _n · 3nH₂O · 0.5n(CH₃OH) (1) and [Cd₃(C₇H₂NO₅)₂ · 10(H₂O)] · 2H₂O ·0.5CH₃OH (2) were synthesized and characterized by X-ray single-crystal diffraction. The crystal structure of 1 reveals that both Cds are seven-coordinate with pentagonal bipyramid geometries. Coordination polyhedra are interlinked into a 1-D chain, further linked by hydrogen bonds into a 3-D network. Complex 2 is a discrete structure, then independent [Cd₃(C₇H₂NO₅)₂ · 10(H₂O)] are linked by hydrogen bonds into a 3-D network. The optical properties of 1 and 2 were investigated with fluorescent spectra; both exhibit strong green luminescence probably originating from π–π* transition of the ligand.     

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, structure and magnetic properties of cobalt(II) and copper(II) coordination polymers assembled by phthalate and 4-methylimidazole

New coordination polymers [M(Pht)(4-MeIm)₂(H₂O)]_n (M=Co (1), Cu (2); Pht²⁻=dianion of o-phthalic acid; 4-MeIm=4-methylimidazole) have been synthesized and characterized by IR spectroscopy, X-ray crystallography, thermogravimetric analysis and magnetic measurements. The crystal structures of 1 and 2 are isostructural and consist of [M(4-MeIm)₂(H₂O)] building units linked in infinite 1D helical chains by 1,6-bridging phthalate ions which also act as chelating ligands through two O atoms from one carboxylate group in the case of 1. In complex 1, each Co(II) atom adopts a distorted octahedral N₂O₄ geometry being coordinated by two N atoms from two 4-MeIm, three O atoms of two phthalate residues and one O atom of a water molecule, whereas the square-pyramidal N₂O₃ coordination of the Cu(II) atom in 2 includes two N atoms of N-containing ligands, two O atoms of two carboxylate groups from different Pht, and a water molecule. An additional strong O-H?O hydrogen bond between a carboxylate group of the phthalate ligand and a coordinated water molecule join the 1D helical chains to form a 2D network in both compounds. The thermal dependences of the magnetic susceptibilities of the polymeric helical Co(II) chain compound 1 were simulated within the temperature range 20-300 K as a single ion case, whereas for the Cu(II) compound 2, the simulations between 25 and 300 K, were made for a linear chain using the Bonner-Fisher approximation. Modelling the experimental data of compound 1 with MAGPACK resulted in: g=2.6, |D|=62 cm⁻¹. Calculations using the Bonner-Fisher approximation gave the following result for compound 2: g=2.18, J=-0.4 cm⁻¹.     

Synthesis,crystal structure and characterization of 3-thiophene aldehyde thiosemicarbazone and its complexes with cobalt(II), nickel(II) and copper(II)

The reaction of cobalt(II), nickel(II), copper(II) chlorides and bromides with 3-thiophene aldehyde thiosemicarbazone (3TTSCH) leads to the formation of a series of new complexes: [Co(3TTSC)₂], [Ni(3TTSC)₂], [CuCl(3TTSC)]₂, [CuBr(3TTSC)]₂ and [CuBr₂(3TTSCH)]. The crystal structures of the free ligand and of the compound [Ni(3TTSC)₂] have been determined by X-ray diffraction methods. For all these complexes, the central ion is coordinated through the sulfur and the azomethine nitrogen atom of the thiosemicarbazone. [Co(3TTSC)₂], [Ni(3TTSC)₂] and [CuBr₂(3TTSCH)] are mononuclear species, while [CuCl(3TTSC)]₂ and [CuBr(3TTSC)]₂ are binuclear complexes.     

Hydrothermal Synthesis of Five New Coordination Polymers Based on Benzophenone‐2, 4′‐dicarboxylic Acid and N‐Donor Spacers

Five new coordination polymers, namely, [Ni₂(L)₂(4, 4′‐bipy)₃)] · H₂O]_n ( 1 ), [Ni₂(L)₂(O) (bpp)₂]_n ( 2 ), [Zn(L)(bib)_0.5]_n ( 3 ), [Zn(L)(PyBIm)]_n ( 4 ), and [Zn₃(L)₂(OH)(im)]_n ( 5 ) [H₂L = benzophenone‐2, 4′‐dicarboxylic acid, 4, 4′‐bipy = 4, 4′‐bipyridine, bpp = 1, 3‐bis(4‐pyridyl)propane, PyBIm = 2‐(4‐pyridyl)benzimidazole, and im = imidazole] were synthesized under hydrothermal conditions. Structure determination revealed that compound 1 is a 3D network and exhibits a 4‐connected metal‐organic framework with (4².6³.8) topology, whereas compounds 2 , 3 , 4 , and 5 are two‐dimensional layer structures. In compounds 2 – 4 , dinuclear metal clusters are formed through carboxylic groups. In compound 5 , trinuclear metal clusters are formed through μ₃‐OH and carboxylic groups. The carboxylic groups exhibit three coordination modes in compounds 1 – 5 : monodentately, bidentate‐chelating, and bis‐monodentately. Furthermore, the luminescent properties for compounds 3 , 4 , and 5 were investigated.     

Synthesis,characterization, and properties of copper and manganese complexes with 5-(benzimidazol-1-ylmethyl)isophthalate

Four new complexes, [Cu(L)] (1), [Cu₂(L)(dpe)_0.5]?·?2.5H₂O (2), [Mn(L)] (3), and [Mn(L)(pybim)] (4) [H₂L?=?5-(benzimidazol-1-ylmethyl)isophthalic acid, dpe?=?1,2-di(pyridin-4-yl)ethylene, pybim?=?2-(pyridin-2-yl)-1H-benzimidazole], have been synthesized under hydrothermal conditions and characterized by single-crystal and powder X-ray diffractions, FT-IR, and elemental analysis. The crystal structural analyses reveal that 1 and 4 are uninodal 3-connected 2-fold interpenetrated 2-D networks with (6³) topology, 2 shows an infinite 1-D double-stranded chain structure, and 3 exhibits a uninodal 4-connected 2-D network with (4⁴?·?6²) topology. The factors influencing the structures of the coordination polymers are discussed. In addition, the thermal stabilities of 1–4, second-order non-linear optical effect of 1, and preliminary magnetic property of 3 have also been investigated.     

The Crystal Structure of Binuclear Metal Complexes of 7-Azaindole: Cu2 (CH3CO2)2 (C7H5N2)2(C7H6N2)2 AND Ni2(C7H5N2)4.2DMF

The crystal and molecular structures have been determined by single-crystal X-ray methods for the binuclear metal ions (II) complexes of 7-azaindole (1H-pyrrolo [2,3-b] pyridine, C₇H₆N₂ denoted by HL), Cu₂(CH₃CO₂)₂.·L₂(HL)₂ and Ni₂L₄.2DMF. The dark green crystal of Cu₂(CH₃CO₂)₂L₂(HL)₂ was found to crystallize in the monoclinic space group P 2₁/n with a = 9.566(2), b = 12.752(2), c = 12.852(4) Å, β = 99.23(3)⁰, V = 1547 Å, Z = 2, the final R = 0.062 and Rw = 0.053 for 1488 observations from 2722 unique reflections. The Cu-Cu distance is 2.747(2), Cu-N (L^?, bridge) is 1.966(7), Cu-N (HL, axial) is 2.229(8), and Cu-O is 2.031(6)Å. The red crystal of Ni₂L₄.2DMF was was found to crystallize in the triclinic space group \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm P \bar 1} $$\end{document} with a = 8.907(5), b = 9.462(2), c = 10.217(2) Å, α = 90.48(2), β = 91.09(3), γ = 110.69(3)⁰, V =805 ų, Z = 1, the final R = 0.063 and Rw = 0.069 for 1489 observations from 2834 unique reflections. The Ni-Ni distance is 2.594(2), Ni-N is 1.905(7) Å. These two molecules lie on crystllographic inversion centers and exhibit ligand disorder.     

Two zinc(II) complexes based on indole-3-acetic acid: crystal structures,fluorescence sensors,and ion exchange with mercury(II)

Two new coordination complexes, [Zn(IA)₂(phen)] (1) and [Zn(IA)₂(4,4′-bipy)] _n ?·?C₂H₅OH (2) (IAH?=?indole-3-acetic acid, phen?=?1,10-phenanthroline, 4,4′-bipy?=?4,4′-bipyridine), have been prepared and characterized by single-crystal X-ray diffraction. Complex 1 is mononuclear and 2 presents a 1-D zigzag chain, in which 4,4′-bipy connects the Zn(II) ions. Both complexes show fluorescence emissions and exhibit fluorescence quenching when Hg²⁺ ions are present. ICP, EDS, and SEM experiments reveal that zinc in both complexes can be exchanged by toxic mercury ions.     

Dinuclear copper(II) complex and 1-D copper(II) complex with taurine Schiff base: synthesis,crystal structure,and properties

A dinuclear copper(II) compound, [Cu(btssb)(H₂O)]₂ · 4(H₂O) (1), and a 1-D chain copper(II) compound, [Cu(ctssb)(H₂O)] _n (2) [where H₂btssb is 2-[(5-bromo-2-hydroxy-benzylidene)-amino]-ethanesulfonic acid and H₂ctssb is 2-[(3,5-dichloro-2-hydroxy-benzylidene)-amino]-ethanesulfonic acid], were prepared and characterized. Compound 1 crystallizes in the monoclinic space group P2₁/c, with a = 10.109(2) Å, b = 20.473(4) Å, c = 6.803(1) Å, β = 100.32(3)°, V = 1385.1(5) ų, and Z = 2; R ₁ for 1796 observed reflections [I > 2σ(I)] was 0.0357. The geometry around each copper(II) can be described as slightly distorted square pyramidal. The Cu^II ··· Cu^II distance is 5.471(1) Å. Compound 1 formed a 1-D network through O–H ··· O hydrogen bonds and 1-D water chains exist. The 1-D chain complex 2 crystallizes in the triclinic space group P 1, with a = 5.030(2) Å, b = 7.725(2) Å, c = 17.011(5) Å, α = 92.706(4)°, β = 97.131(4)°, γ = 102.452(3)°, V = 638.6(3) ų, and Z = 2; R ₁ for 1897 observed reflections [I > 2σ(I)] was 0.0171. In 2, Cu(II) was also a slightly distorted square pyramid formed by two oxygens and one nitrogen from ctssb, one oxygen from another ctssb, and one water molecule. The complex formed a 1-D chain through O–S–O bridge of ctssb ligand. The 1-D chain further constructed a double chain through O?H ··· O hydrogen bonds.     

Syntheses,crystal structures,electrochemical studies,and antioxidant activities of zinc(II) and copper(II) complexes with bis(2-benzimidazolyl) aniline derivatives

Two ligands, bis(benzimidazol-2-ylmethyl) aniline (bba) and bis(N-methyl-benzimidazol-2-ylmethyl) aniline (Mebba), and their transition metal complexes [Zn(bba)(Br)₂]·2DMF (1) and [Cu(Mebba)(Br)₂]·2DMF (2) have been synthesized and characterized by elemental analyses, molar conductivities, UV–vis spectra, IR spectra, NMR spectroscopy, and X-ray crystallography. The structure around Zn(II) can be described as distorted tetrahedral. Complex 2 can be described as distorted trigonal bipyramidal. Cyclic voltammograms of 2 indicate a quasireversible Cu²⁺/Cu⁺ couple. Additionally, the antioxidant activities of the free ligands and their complexes were determined by the superoxide and hydroxyl radical scavenging methods in vitro. Complexes 1 and 2 possess potent hydroxyl radical scavenging activity and better than standard antioxidants such as vitamin C and mannitol. Complex 2 possesses excellent superoxide radical activity.     

Synthesis,crystal structures,and characterization of two Co(II) coordination polymers with 3-pyrid-3-ylbenzoic acid

Two pyridinecarboxylato-bridged coordination polymers {[Co(pbc)₂(H₂O)] · H₂O} _n (1) and [Co(pbc)₂] _n (2) (Hpbc = 3-pyrid-3-ylbenzoic acid) have been synthesized by the hydrothermal method and characterized by X-ray single crystal diffraction. In 1, pbc^? ligands link two Co(II) centers as μ₂-N,O and μ₂-N,O,O. Co(II) is six coordinate, octahedral. In 2, Co(II) is coordinated by four oxygens and two nitrogens. The ligands are μ₂-N,O,O and μ₃-N,O,O. Through different pbc^? ligands, 2 generates a 3-D network composed of six-connected nodes. Compound 2 exhibits good photoluminescence, whereas 1 is nonemissive at room temperature.     

Four Ni(II), Co(III), Cd(II) complexes based on 5-(pyrazol-1-yl)nicotinic acid: synthesis,X-ray single crystal structure,in vitro cytotoxicity,apoptosis and molecular docking studies

We have developed complexes [Ni₂(L)₂(H₂O)₄]_n (1), [Co₂(L)₂(H₂O)₄]_n (2), [Cd₂(L)₂(H₂O)₂Cl₂]n (3) and [Cd₂(L)₂(H₂O)₂]_n (4), where HL = 5-(pyrazol-1-yl) nicotinic acid. All complexes were characterized by elemental analysis, IR spectroscopy and single crystal X-ray diffraction, showing monoclinic crystal lattice with space group P2₁/c (1), P2₁/c (2), P2₁/c (3), and triclinic crystal lattice with space group P-1 (4), separately. In vitro antitumor screening (MTT method) revealed that 3 exhibited better inhibitory activities than the commercial anticancer drug cisplatin against HeLa tumor cell lines, with IC50 values 9?±?2. The bindings of these complexes with Fish Sperm DNA were measured by electronic absorption spectra and fluorescence spectroscopy, showing K_sq 0.1867 (1), 0.1589 (2), 0.2332 (3), and 0.1411 (4), with the binding affinities ranked 3?>?1 > 2?>?4. The experimental result showed that these complexes could bind DNA via intercalation. The ability of 1–4 to cleave the pBR322 plasmid DNA was demonstrated by gel electrophoresis assay. The experiment verified that these complexes could induce DNA damage. In addition, flow cytometric analysis showed that 1–4 induced apoptosis of HeLa tumor cell lines; as time increases, the apoptotic impact becomes increasingly significant. The potential of 1–4 as anticancer agents were examined using molecular docking of the complexes with DNA.

     

Syntheses and Structures of two Cobalt Coordination Polymers with Iminodiacetate Ligands: [CoII2(ida)2(H2O)2]n and [Na2CoIII2(ida)4(H2O)4]n·2nH2O

Two cobalt coordination polymers [Co^II₂(ida)₂(H₂O)₂]_n ( 1 ) and [Na₂Co^III₂(ida)₄(H₂O)₄]_n·2nH₂O ( 2 ) (H₂ida = iminodiacetic acid) have been synthesized and characterized by single‐crystal X‐ray diffraction analysis. Compound 1 exhibits a two‐dimensional framework, in which two cobalt atoms exhibit different coordination environments: one is equatorially coordinated by two ida ligands, while another is coordinated by two water molecules and four ida ligands. It is most interesting that, in compound 2 , the ida ligands exhibit different coordination modes. The organic coordination anions [Co^III(ida)₂]^— are linked up by sodium ions to form a two‐dimensional layer.     

Trinuclear Schiff base complexes with uranium(V) and copper(II) or zinc(II) ions

Treatment of the uranium(IV) complexes [{ML¹(py)}₂U^IV] (M = Cu, Zn; L¹ = N,N′-bis(3-hydroxysalicylidene)-1,3-propanediamine) with silver nitrate in pyridine led to the formation of the corresponding cationic uranium(V) species which were found to be thermally unstable and were converted back into the parent U^IV complexes; no electron transfer was observed in solution between the U^IV and U^V compounds. In the crystals of [{ML¹(py)}₂U^IV][{ML¹(py)}₂U^V][NO₃], the neutral U^IV and cationic U^V species are clearly identified by the distinct U–O distances. Similar reaction of [{ZnL²(py)}₂U^IV] [L² = N,N′-bis(3-hydroxysalicylidene)-1,4-butanediamine] with AgNO₃ gave crystals of [{ZnL²(py)}U^V{ZnL²(py)₂}][NO₃] but the copper counterpart was not isolated. Crystals of [{ZnL¹(py)}₂U^V][OTf] · THF (OTf = OSO₂CF₃) were obtained fortuitously from the reaction of [Zn(H₂L¹)] and U(OTf)₃.     

Syntheses,structures, and fluorescent properties of four Co(II) coordination polymers based on 5-hydroxyisophthalic acid and structurally related bis(benzimidazole) ligands

Four cobalt(II) coordination polymers, {[Co(HO-BDC)(bbp)]}_n (1), {[Co(HO-BDC)(bmbp)₂]·(H₂O)₂}_n (2), {[Co(HO-BDC)(bbb)]}_n (3), and {[Co₂(HO-BDC)₂(bmbb)₂]·(H₂O)₃}_n (4), where HO-H₂BDC?=?5-hydroxyisophthalic acid, bbp = 1,3-bis(benzimidazol-1-yl)propane, bmbp = 1,3-bis(2-methyl-benzimidazol-1-yl)propane, bbb = 1,4-bis(benzimidazol-1-yl)butane, and bmbb = 1,4-bis(2-methyl-benzimidazol-1-yl)butane, have been synthesized and characterized by elemental analyses, IR spectra, single-crystal X-ray diffraction, thermogravimetric analyses, and fluorescence properties. Compounds 1 and 3 are 4-connected 2-D networks with (4⁴·6²) topology. Compound 2 is a 1-D chain, while 4 features a 1-D ladder. These 1-D and 2-D complexes are further connected by hydrogen bonds to form 3-D supramolecular architectures. Complexes 1–4 showed very strong yellow luminescence emission.     

Syntheses,structures, and characterizations of two coordination polymers assembled from zinc(II) salts with 1,2-bis[3-(1,2,4-triazolyl)-4-amino-5-carboxylmethylthio]ethane

Two new coordination polymers, [ZnL] _n (1) and {[Zn(phen)(L)(H₂O)]?·?3H₂O} _n (2) (H₂L?=?1,2-bis[3-(1,2,4-triazolyl)-4-amino-5-carboxylmethylthio]ethane, phen?=?1,10-phenanthroline), have been synthesized and characterized by elemental analysis, IR, and X-ray diffraction. Polymer 1 is a 1-D infinite chain (space group P 1) and further forms a 3-D supramolecular structure by S?···?S interactions and hydrogen bonds. Polymer 2 displays a mononuclear structure (space group P 1) and extends into a 3-D supramolecular structure through hydrogen bonds. In addition, spectra and thermal stability of 1 and 2 are also discussed. Strong luminescence characteristics of both polymers are found, suggesting their potential applications as luminescent materials.     

(Me2NH2)[(Ph3Sn)3(MoO4)2], ein Triorganozinnmolybdat mit Schichtstruktur

(Me₂NH₂)[(Ph₃Sn)₃(MoO₄)₂], a Triorganotin Molybdate with Layer Structure The reaction of [(Ph₃Sn)₂MoO₄] with (Me₂NH₂)Cl in an acetonitrile/water mixture leads to the formation of (Me₂NH₂)[(Ph₃Sn)₃(MoO₄)₂] ( 1 ). ( 1 ) crystallizes in the space group Pca2₁ with a = 1967.0(4), b = 1353.1(2) and c = 2176.6(5) pm. In the crystal structure of 1 Ph₃SnO₂ bipyramides and MoO₄ tetrahedra are linked by corner sharing to give a layer structure. Additionally the layers are connected by O···H···N hydrogen bridges between MoO₄ groups and [Me₂NH₂]⁺ ions to give a 3D network structure.     

Three Ag(I) and Cu(II) complexes of 4-pyridin-4-yl-(1,3) dithiol-2-one

Single crystals of Ag(I) and Cu(II) complexes with 4-pyridin-4-yl-(1,3) dithiol-2-one (PYDO), [Ag(PYDO)₂]ClO₄, [Ag(PYDO)₂(NO₃)], and [Cu(PYDO)₂(NO₃)₂] have been prepared and characterized. PYDO displays excellent coordination to Cu(II) and Ag(I). The 1,3-dithiol five-member ring is an electron donor that enhances the coordination ability of the py group. HOMO-1 σ coordination and d–π electron back-donating from metal to ligand (LUMO) are suggested based on the calculation. Weak interactions and secondary bonds from the anion to cation play an important role in the molecular assembly.