Synthesis,Spectral, Thermal Studies of Co(II), Ni(II), Cu(II) and Zn(II)‐arginato Complexes. Crystal Structure of Monoaquabis(arginato‐κO,κN)copper(II). [Cu(arg)2(H2O)].NaNO3

Transition metal complexes of arginine (using Co(II), Ni(II), Cu(II) and Zn(II) cations separately) were synthesized and characterized by FTIR, TG/DTA‐DrTG, UV‐Vis spectroscopy and elemental analysis methods. Cu(II)‐Arg complex crystals was found suitable for x‐ray diffraction studies. It was contained, one mole Cu^II and Na⁺ ions, two arginate ligands, one coordinated aqua ligand and one solvent NO₃^? group in the asymmetric unit. The principle coordination sites of metal atom have been occupied by two N atoms of arginate ligands, two carboxylate O atoms, while the apical site was occupied by one O atom for Cu^II cation and two O atoms for Co^II, Ni^II, Zn^II atoms of aqua ligands. Although Cu^II ion adopts a square pyramidal geometry of the structure. Co^II, Ni^II, Zn^II cations have octahedral due to coordination number of these metals. Neighbouring chains were linked together to form a three‐dimensional network via hydrogen‐bonding between coordinated water molecule, amino atoms and O atoms of the bridging carboxylate groups. Cu^II complex was crystallized in the monoclinic space group P2₁, a = 8.4407(5) Å, b = 12.0976(5) Å, c = 10.2448(6) Å, V = 1041.03(10) ų, Z = 2. Structures of the other metal complexes were similar to CuII complex, because of their spectroscopic studies have in agreement with each other. Copper complex has shown DNA like helix chain structure. Lastly, anti‐bacterial, anti‐microbial and anti‐fungal biological activities of complexes were investigated.     

A novel O–Zn bridging polymer complex of 2,6‐bis[bis(carboxylatomethyl)aminomethyl]‐4‐methylphenolate

A new one‐dimensional coordination polymer, catena‐poly[[acetatohexaaqua{μ₄‐2,6‐bis[bis(carboxylatomethyl)aminomethyl]‐4‐methylphenolato}trizinc(II)] octahydrate], [Zn₃(C₁₇H₁₇N₂O₉)(C₂H₃O₂)(H₂O)₆]·8H₂O, is a trinuclear complex consisting of three zinc centers joined by a phenolate bridge and Zn(H₂O)₄ units. In each complex polymer unit, the three Zn atoms have different coordination modes. Of the two phenolate‐bridged Zn ions, one adopts a distorted octahedral coordination composed of two carboxylate ligands, one tertiary N atom, two water molecules and the bridging phenolate ligand, while the other adopts a pyramidal geometry composed of two carboxylate ligands, one tertiary N atom from another coordination arm, one acetate anion as the counter‐anion and the bridging phenolate ligand. The third type of Zn centre is represented by two independent Zn atoms lying on inversion centres. They both have an octahedral coordination consisting of four O atoms from four water molecules and two acetate carbonyl O atoms from the ligand. The latter Zn atoms join the above‐mentioned binuclear complex units through O atoms of the carboxylate groups into an infinite chain. Neighboring aromatic rings are distributed above and below the chain in an alternating manner. Between the coordination chains, the Zn...Zn separations are 5.750 (4) and 6.806 (4) Å. The whole structure is stabilized by hydrogen bonds formed mainly by solvent water molecules.     

Two new potential optical materials: Co(II) and Ni(II) 3-fluorobenzoate complexes with pyridine-3-carboxamide

Two new complexes, [Co(3-fba)₂(na)₂(H₂O)₂] (1) and [Ni(3-fba)₂(na)₂(H₂O)₂] (2) (where 3-fba = 3-fluorobenzoate and na?=?pyridine-3-carboxamide, nicotinamide), were synthesized and characterized using different techniques (elemental analysis, FT-IR, UV-Vis spectrophotometer, single-crystal X-ray diffraction, fluorescence spectroscopy, and TGA/DTA analysis). X-ray structural analysis revealed that 1 and 2 are isostructural and exhibit distorted octahedral coordination geometry. In each molecule, metal atoms (Co⁺² and Ni⁺²) are linked by two 3-fluorobenzoate anions, two pyridine-3-carboxamide ligands, and two water molecules per formula unit. The 3-fluorobenzoate and pyridine-3-carboxamide are monodentate through a carboxylate oxygen atom and the nitrogen atom of the pyridine ring, respectively. UV-Vis results showed that the studied complexes have absorption edges similar to semiconductor structures. Namely, 1 and 2 indicated emission behaviors around 370?nm and 361?nm, respectively.     

A tetrahedrally coordinated AgI and NiII complex with a two‐dimensional framework containing one‐dimensional helical chains

The title complex, poly[bis(μ₆‐pyridine‐2,6‐dicarboxylato N‐oxide)nickel(II)disilver(I)], [Ag₂Ni(C₇H₃NO₅)₂]_n or [Ag₂Ni(pydco)₂]_n (H₂pydco = pyridine‐2,6‐dicarboxylic acid N‐oxide), has a two‐dimensional sheet structure. The two carboxylate groups adopt two coordination modes. The Ni^II ion displays a distorted octahedral geometry, bonded to two carboxylate O atoms of two different pydco ligands and four O donors from another two ligands, i.e. two carboxylate O atoms and two N‐oxide O atoms. The Ag^I ion adopts a tetrahedral coordination, linked by three O atoms of three different carboxylate groups and an N‐oxide O atom.     

Heterovalent trinuclear Co(III)-Co(II)-Co(III) complexes with N-(2-Carboxyethyl)salicylaldimines

The heterovalent trinuclear cobalt complexes [Co₂^IIIL₄ ⁱ · Co^II(H₂O)₄] · nXmY (L ⁱ are deprotonated Schiff bases derived from substituted salicylaldehydes and β-alanine; i = 1–3) were obtained and characterized. An X-ray diffraction study of the trinuclear cobalt complex with N-(2-carboxyethyl)salicylaldimine showed that the central Co(II) ion and the terminal Co(III) ions are linked by bridging carboxylate groups. Either terminal Co(III) atom is coordinated to two ligand molecules. They form an octahedral environment consisting of two azomethine N atoms, two phenolate O atoms, and two O atoms of two carboxylate groups. The central Co(II) atom is coordinated to four water molecules and to two O atoms of two bridging carboxylate ligands involved in the coordination sphere of the terminal Co(III) atoms.     

Poly[tetra‐μ2‐l‐lactato‐indium(III)sodium(I)]

The asymmetric unit of the title compound, [InNa(C₃H₅O₃)₄]_n, consists of one In^III ion, one Na^I ion and four crystallographically independent l ‐lactate monoanions. The coordination of the In^III ion is composed of five carboxylate O and two hydroxy O atoms in a distorted pentagonal–bipyramidal coordination geometry. The Na^I ion is six‐coordinated by four carboxylate O atoms and two hydroxy O atoms from four l ‐lactate ligands in a distorted octahedral geometry. Each In^III ion is coordinated by four surrounding l ‐lactate ligands to form an [In(l ‐lactate)₄]⁻ unit, which is further linked by Na^I ions through Na—O bonds to give a two‐dimensional layered structure. Hydrogen bonds between the hydroxy groups and carboxylate O atoms are observed between neighbouring layers.     

Poly[[aqua(μ7‐ethylenediaminetetraacetato)dicadmium(II)] monohydrate]

The title compound, {[Cd₂(C₁₀H₁₂N₂O₈)(H₂O)]·H₂O}_n, consists of two crystallographically independent Cd^II cations, one ethylenediaminetetraacetate (edta) tetraanion, one coordinated water molecule and one solvent water molecule. The coordination of one of the Cd atoms, Cd1, is composed of five O atoms and two N atoms from two tetraanionic edta ligands in a distorted pentagonal–bipyramidal coordination geometry. The other Cd atom, Cd2, is six‐coordinated by five carboxylate O atoms from five edta ligands and one water molecule in a distorted octahedral geometry. Two neighbouring Cd1 atoms are bridged by a pair of carboxylate O atoms to form a centrosymmetric [Cd₂(edta)₂]⁴⁻ unit located on the inversion centre, which is further extended into a two‐dimensional layered structure through Cd2—O bonds. There are hydrogen bonds between the coordinated water molecules and carboxylate O atoms within the layer. The solvent water molecules occupy the space between the layers and interact with the host layers through O—H...O and C—H...O interactions.     

Cadmium Iodide Complex with 4-Aminomethylbenzoic Acid: Synthesis,Crystal Structure,and Luminescent Properties

[СdI₂(4-АmbaH)₂] · H₂O has been synthesized by the reaction between CdI₂ and 4-aminomethylbenzoic acid (4-AmbaH) in an aqueous solution. According to X-ray diffraction data, a 4-AmbaH aromatic molecule crystallizes in the form of a zwitterion with protonation of the NH ₃ ⁺ amino group and deprotonation of the carboxylate group, which is chelately coordinated to the Cd²⁺ ion. In addition to two iodine atoms, the Cd²⁺ atom located on the double crystallographic axis is coordinated to the chelate carboxylate O(1) and O(2) atoms of two crystallographically equivalent ligands 4-AmbaH. The octahedral geometry of the Cd²⁺ ion is strongly distorted due to the chelate addition of 4-AmbaH. The chelate coordination of COO–groups is confirmed by IR spectroscopy data. The complex has luminescent properties.     

A three-dimensional highly stable cobalt(II) metal–organic framework based on terephthalic acid: synthesis, crystal structure, thermal and physical properties

A metal?Corganic framework complex, [Co(??₃?Ctp)(??₂?pyz)] _n , where H₂tp?=?1,4-benzenedicarboxylic acid (terephthalic acid) and pyz?=?pyrazine, has been synthesized under hydrothermal conditions and characterized by physico-chemical and spectroscopic methods, thermogravimetric analysis and single-crystal X-ray diffraction. Each Co(II) center is surrounded by four carboxylate oxygen atoms from three tp ligands and two nitrogen atoms from two pyrazine ligands, giving a distorted octahedral geometry. The entire framework is made up of two-dimensional sheets of dicobalt ions linked via terephthalate ligands to form rectangles. The sheets are then linked into each other via the axial pyrazine ligands, forming an interlocked 3-D network, which is finally arranged as an ABAB interconnected pattern. Photoluminescence measurements for the polymer in the solid state show an emission at 414?nm, which suggests this complex as a potential blue-light material. The electrochemical behavior of a modified carbon paste electrode prepared from the complex has been studied by cyclic voltammetry, indicating quasi-reversible redox behavior.     

A Three—Dimensional Lead(II) Polymer with Bridging Saccharinate and Unusually Coordinated Acetate Ligands — Synthesis,IR Spectra,and Crystal Structure of [Pb(H2O)(μ‐OAc)(μ‐sac)]n

The complex [Pb(H₂O)(μ‐OAc)(μ‐sac)]n with acetate (OAc) and saccharinate (sac) ligands was characterized by IR, elemental analysis and X‐ray crystallography. The mixed‐anion lead(II) complex crystallizes in the triclinic crystal system with the space group of P1¯. The single crystal X‐ray analysis shows that the complex is a coordination polymer in which the lead(II) ions have a highly distorted pentagonal bipyramidal coordination geometry. Lead(II) ions are bridged by carboxylate groups in a zigzag arrangement forming one‐dimensional infinite chains, which are also linked by sac bridges and aromatic π‐π contacts between the adjacent phenyl rings of sac ligands, resulting in a three‐dimensional network. One water molecule coordinates the lead(II) ion and also forms weak hydrogen bonds with the sulfonyl oxygen atoms of the neighboring sac ligands. The sac ligand acts as a bridging ligand through the nitrogen and carbonyl oxygen atoms, while the carboxylate moiety of the acetate ligand shows an unusual (bidentate, and bridging) coordination behaviour, which was observed for the first time in the structure.     

catena‐Poly­[[di­aqua­cadmium(II)]‐μ‐5‐carboxyimidazole‐4‐carboxylato‐κ4N1,O5:O4,N3]

A new cadmium coordination polymer, [Cd(C₅H₂N₂O₄)(H₂O)₂]_n, possesses a one‐dimensional zigzag chain structure built from Cd^II centers bridged sequentially by pairs of O and N atoms of the 5‐carboxyimidazole‐4‐carboxylate ligand. The Cd^II center is in a distorted octahedral geometry, being coordinated by two O atoms from two coordinated water mol­ecules [Cd—O = 2.322 (7) and 2.364 (7) Å], and by two N atoms [Cd—N = 2.222 (6) and 2.232 (6) Å] and two carboxyl O atoms [Cd—O = 2.383 (6) and 2.414 (6) Å] from two 5‐carboxyimidazole‐4‐carboxylate ligands.     

Synthesis, spectroscopic, thermal, crystal characterization and biological activity of [Ni(phen)3][Ni(dipic)2]2.17H2O (H2dipic:pyridine-2,6-dicarboxylic acid, phen: 1,10-phenanthroline)

The new [Ni(phen)₃][Ni(dipic)₂]₂.17H₂O (1) (phen = 1,10-phenanthroline, dipic = dipicolinate)) has been prepared and characterized by elemental analysis, IR, UV-Vis, magnetic measurement and single crystal X-ray diffraction. The complex consists of two tris(1,10-phenanthroline)nickel(II) cations, two bis(dipicolinato)nickelate(II) anions and seventeen uncoordinated water molecules. The Ni(II) complex crystallizes in the triclinic space group P-1. The complex consisting of cation has distorted octahedral coordination by three bidentate phen ligands. In the complex anion, each dipic ligand simultaneously exhibits tridentate coordination modes through N atom of pyridine ring and oxygen atoms of the carboxylate groups. The crystal packing of 1 is a composite of intermolecular hydrogen bonding, π-π and C-H?π interactions. The complex has also been investigated in terms of biological activity and it showed high activity against S. aureus from Gram positive bacteria and C. albicans from yeast tested.     

Poly[[triaquazinc(II)]‐μ3‐4‐nitrophthalato‐κ3O1:O2:O2′]

In the title complex, [Zn(C₈H₃NO₆)(H₂O)₃]_n, the two carboxylate groups of the 4‐nitrophthalate dianion ligands have monodentate and 1,3‐bridging modes, and Zn atoms are interconnected by three O atoms from the two carboxylate groups into a zigzag one‐dimensional chain along the b‐axis direction. The Zn atom shows distorted octahedral coordination as it is bonded to three O atoms from carboxylate groups of three 4‐nitrophthalate ligands and to three O atoms of three non‐equivalent coordinated water molecules. The one‐dimensional chains are aggregated into two‐dimensional layers through inter‐chain hydrogen bonding. The whole three‐dimensional structure is further maintained and stabilized by inter‐layer hydrogen bonds.     

A three‐dimensional cadmium(II) coordination polymer: poly[[[μ‐4,4′‐(propane‐1,3‐diyl)dipyridine‐κ2N:N](μ‐3,3′‐thiodipropionato‐κ3O,O′:O)cadmium(II)] monohydrate]

In the title coordination polymer, {[Cd(C₆H₈O₄S)(C₁₃H₁₄N₂)]·H₂O}_n, the Cd^II atom displays a distorted octahedral coordination, formed by three carboxylate O atoms and one S atom from three different 3,3′‐thiodipropionate ligands, and two N atoms from two different 4,4′‐(propane‐1,3‐diyl)dipyridine ligands. The Cd^II centres are bridged through carboxylate O atoms of 3,3′‐thiodipropionate ligands and through N atoms of 4,4′‐(propane‐1,3‐diyl)dipyridine ligands to form two different one‐dimensional chains, which intersect to form a two‐dimensional layer. These two‐dimensional layers are linked by S atoms of 3,3′‐thiodipropionate ligands from adjacent layers to form a three‐dimensional network.     

Synthesis,crystal structure,and catalytic properties of a one-dimensional nickel(II) polymer

The title complex [Ni₂(C₁₀H₉N₃)₂(C₁₄H₈O₅)₂] _n , which has an inversion center, midway between two Ni(II) atoms forms a one-dimensional polymer bridged by 4,4′-oxydibenzoate ligands with a Ni…Ni separation of 14.4705(11) Å. The Ni(II) atom is six-coordinated by two N atoms of a bis(2-pyridyl)amine ligand and four O atoms from two 4,4′-oxydibenzoate ligands, to form a distorted octahedron coordination geometry and then are linked via N-H…O and C-H…O hydrogen bonding into a polymeric ribbon structure. The activity and selectivity profiles of the polymer indicate that the optimization temperature and time span are 175°C and 30–40 min for the dehydration of cyclohexanol, respectively.     

Polymeric and monomeric dipicolinate complexes with 4-hydroxymethyl pyridine: spectral, structural, thermal and electrochemical characterization

Polymeric copper(II), [Cu(μ-dpc)(μ-4-hymp)] _n (1), and monomeric nickel(II), [Ni(dpc)(4-hymp)(H₂O)₂]·H₂O (2), (dpc: dipicolinate, 4-hymp: 4-hydroxymethyl pyridine), dipicolinate complexes have been prepared and characterized by spectroscopic (IR, UV–Vis, EPR), thermal (TG/DTA), X-ray diffraction technique and electrochemical methods. In both the dipicolinate complexes, the dpc dianion acts as a tridentate ligand. In polymeric copper(II) complex, the 4-hymp and dpc ligands adopt a bridging position between the Cu(II) centers, forming the elongated octahedral geometry. The polymeric chains are linked to one another via O–H···O hydrogen bond interactions, forming the 3-D polymeric structure. The Ni(II) ion is bonded to dpc ligand through pyridine N atom together with one O atom of each carboxylate group, two aqua ligands and N pyridine atom of 4-hymp, forming the distorted octahedral geometry. The Ni(II) complexes are connected to one another via O–H···O hydrogen bonds, forming R ₄²(18) motifs in 2-D pattern. The powder EPR spectra of copper(II) complex have indicated that the paramagnetic center is in rhombic symmetry with the Cu²⁺ ion having distorted octahedral geometry. IR and UV–Vis spectroscopes all agree with the observed crystal structure.     

The Crystal Structures of Two Polymorphic Forms of a Calcium(II) Complex with Pyridine-2,6-Dicarboxylate,Water and Nitrate Ligands

The calcium (II) complex: catena-mono(μ-pyridine-2,6-dicarboxylato-O:O:N;O') (diaqua-O)mono (nitrato-O:O)calcium(II) exists in two polymorphic forms. Each contains molecular ribbons in which adjacent Ca(II) ions are bridged by monodentate oxygen atoms donated by one carboxylate group of the pyridine-2,6-carboxylate ligand. Apart from this bridging oxygen atom, the Ca(II) ion is coordinated by two carboxylate oxygen atoms contributed by a different carboxylate group of the ligand molecule, the heteroring nitrogen atom, two water oxygen atoms and two oxygen atoms of a nitrate group giving rise to a distorted pentagonal bipyramid as a coordination polyhedron. The structures of the polymorphic modifications differ in the way in which the nitrate ligands are oriented with respect to the equatorial planes of the adjacent Ca(II) coordination polyhedra: the trans mode in the α-form; the cis mode in the β-form. In both forms, hydrogen bonds operate between the carboxylate oxygen atoms, water oxygen atoms and nitrate oxygen atoms.     

Synthesis,structure and luminescent properties of a new two-dimensional (4,4) network cadmium coordination polymer with dicyanamide and benzimidazole ligands

The new cadmium coordination polymer [Cd(bim)₂(dca)₂]_n (1), (bim?=?benzimidazole, dca?= dicyanamide) was synthesized and characterized by IR, thermogravimetric analysis and luminescent properties. The coordination geometry of cadmium atom is distorted octahedral, coordinated equatorially by four nitrogen atoms from four dicyanamide ligands, and axially by two nitrogen atoms from two benzoimidazoles. Each dca ligand links two cadmium(II) atoms and 1 forms a two-dimensional (4,4) network.     

The first two structurally characterized energetic catalysts derived from dinitropyridone

Two energetic catalysts, 3,5-dinitro-2-pyridonate of lead (II) (Pb(2DNPO)₂, 1) and 3,5-dinitro-4-pyridone-N-hydroxylate tetrahydrate of copper (II) (Cu(4DNPOH)₂(H₂O)₄, 2) were characterized by elemental analysis, FT-IR, TG-DSC and structurally characterized by X-ray single-crystal diffraction analysis. X-ray powder diffraction analysis of complex 1 confirmed the phase homogeneity of the polycrystalline sample. Crystal data for 1: monoclinic, space group P 21/n, a = 8.5253(9), b = 9.2938(10), c = 19.654(2) Å, β = 102.289(2)°, V = 1521.6(3) ų, Z = 4; 2: monoclinic, space group P 21/n , a = 8.3705(10), b = 9.9307(12), c = 10.5771(12) Å, β = 98.021(2)°, V = 870.62(18) ų, Z = 2. The complex 1 is a one-dimensional coordination polymer with each Pb(II) atom being six-coordinated, forming a heavily distorted octahedral geometry, by two nitrogen and four oxygen donors. Each ligand links the Pb(II) ions in a chelating bridging mode using nitrogen and oxygen atoms of its pyridonate part. The complex 2 is a copper (II) complex with a compressed octahedral geometry. The Cu(II) atom locates on the equatorial positions defined by oxygen atoms of four water molecules. Its axial positions are filled with two oxygen donors of the pyridine-N-hydroxylate moieties of two ligands. The abundant hydrogen bonds link the molecules into one-dimensional chains. Both the complexes represent the first two examples of the energetic catalysts containing dinitropyridine derivatives characterized crystallographically     

Synthesis,Crystal Structure and Electrochemical Behavior of a Fe(II) Complex of 8-Mercaptoquinoline (Hmtq) with Trimethylphosphite Participation

The mononuclear complex Fe(II)(mtq)₂{P(OCH₃)₃}₂ (Hmtq = 8-Mercaptoquinoline) with mixed N-heterocyclic thiolato and phosphite ligands was synthesized and characterized by X-ray crystallography and cyclic voltammetric measurement. The title complex crystallizes in the triclinic space group P-1 with a = 8.929(4), b = 9.965(3), c = 16.913(11) Å, α = 76.21(10), β = 80.89(10), γ= 68.010(10)°, V = 1351.2(11) ų. The Fe(II) atom exhibits an elongated octahedral geometry composed of N₂S₂P₂ donors. The equatorial plane is made up of two cis-oriented N donors from the thiolato ligands and two cis-oriented monodentate P(OCH₃)₃ ligands. The apical sites are occupied by two trans-oriented S atoms from the mtq^? ligands. The thione form is predominant coordination mode of 8-mercaptoquinoline with the N and S donors bound to the Fe(II) to form five-membered chelate rings. The structural feature of the mononuclear Fe(II) complex with mixed phosphite and thiolate ligands is summarized.