Complexes of zinc(II) and cadmium(II) with N-phthaloylglycinate,imidazole, 5-amino tetrazole and 2,4,6- tris (2-pyridyl)-1,3,5-triazine. X-ray crystal structure of [Cd(imi)3(N-phthgly)2]·2H2O

Complexes of Zn(II) and Cd(II) with N-phthaloylglycinate (N-phthgly), imidazole (imi), 5-amino tetrazole (Atz) and 2,4,6-tris(2-pyridyl)-1,3,5-triazine (tptz) were synthesized and characterized by elemental analysis, IR and thermogravimetric analysis. The X-ray crystal structure of the cadmium complex [Cd(imi)₃(N-phthgly)₂]?·?2H₂O is also reported. It crystallizes in the space group P2₁/m. The metal centre is hepta coordinated as a distorted pentagonal bipyramid. The cadmium atom is surrounded by five equatorial atoms (four oxygen atoms of two bidentate N-phthaloylglycinate moieties and a nitrogen atom of an imidazole ligand) and two axial nitrogens of two imidazole rings. In the crystal, the molecules are connected by H-bonds involving water molecules, the carboxylic oxygens of the N-phthaloylglycinate molecules and the imidazole nitrogens.     

N-Phthaloylglycinate ternary complexes with cobalt(II), nickel(II), copper(II), zinc(II) and cadmium(II) metal ions and aromatic mono,bi and tridentate amines

Complexes of N-phthaloylglycinate (N-phthgly) and Co^II, Ni^II, Cu^II, Zn^II and Cd^II containing imidazole (imi), N-methylimidazole (mimi), 2,2-bipyridyl (bipy) and 1,10-phenanthroline (phen), and tridentate amines such as 2,2,2-terpyridine (terpy) and 2,4,6-(2-pyridyl)s-triazine (tptz), were prepared and characterized by conventional methods, i.r. spectra and by thermogravimetric analysis. For imi and mimi ternary complexes, the general formula [M(imi/mimi)₂(N-phthgly)₂]·nH₂O, where M = Co^II, Ni^II, Cu^II and Zn^II applies. For Cd^II ternary complexes with imi, [Cd(imi)₃(N-phthgly)₂]·2H₂O applies. For the bi and tridentate ligands, ternary complexes of the formula [M(L)(N-phthgly)₂]·nH₂O were obtained, where M = Co^II, Ni^II, Cu^II and Zn^II; L = bipy, phen, tptz and terpy. In all complexes, N-phthgly acts as a monodentate ligand, coordinating metal ions through the carboxylate oxygen, except for the ternary complexes of Co^II, Ni^II and Cu^II with mimi and Cu^II and Zn^II with imi, where the N-phthgly acts as a bidentate ligand, coordinating the metal ions through both carboxylate oxygen atoms.     

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.     

Clemizoledichlorocobalt(II)

The structure of di­chloro­[1‐(p‐chloro­benzyl)‐2‐(1‐pyrrol­idinyl­methyl‐N)‐1,3‐benz­imidazole‐N³]­cobalt(II), [Co­Cl₂(C₁₉­H₂₀ClN₃)], contains a mol­ecule of clemizole bound in a bidentate manner to cobalt through its imidazole and pyrrolidinyl N atoms, with significantly different Co—N distances of 1.976 (5) and 2.126 (5) Å, respectively. The geometry around cobalt is distorted tetrahedral, with significantly different Co—Cl distances of 2.217 (2) and 2.233 (2) Å, and the pyrrolidinyl ring is disordered.     

Synthesis and Spectrothermal Studies of Thermochromic Diamine Complexes of Cobalt(III), Nickel(II) and Copper(II) Squarate. Crystal Structure of [Co(en)3](sq)1.5 · 6H2O

New adducts of ethylenediamine (en), N,N-dimethylethylenediamine (ndmen) and N,N′-dimethylethylenediamine (dmen) with squarate as counter-ions were synthesized and characterized by physico-chemical methods (IR and UV/vis spectroscopy, magnetic susceptibility and thermoanalytical measurements). The crystal structure of tris(ethylenediamine)cobalt(III) 1.5 squarate hexahydrate, [Co(en)₃](sq)_1.5 · 6H₂O, was determined by single crystal X-ray diffraction. Co(III), Ni(II) and Cu(II) ions in the monomeric octahedral tris(ethylenediamine)cobalt(III) 1.5 squarate hexahydrate (1), tris(ethylenediamine)nickel(II) squarate 0.5 hydrate (2) and diaquabis(ethylenediamine)copper(II) squarate dihydrate (3) are chelated by ethylenediamines through two amine nitrogen atoms. Cu(II) atoms in the diaquabis(ndmen)copper(II) squarate (4) and diaquabis(dmen)copper(II) squarate (5) monomeric octahedral complexes are coordinated by ndmen and dmen molecules through two amine nitrogen atoms in a bidentate chelating manner. Water molecules complete the octahedral coordination. The orange (1), violet (4) and violet (5) complexes upon heating transform to claret, green and green species on dehydration, respectively, which revert immediately after cooling in the open atmosphere. The violet (3) complex upon heating loses water molecules yielding a deep blue dehydrated species, which on further heating undergoes an exothermic phase transition accompanied by thermochromism, deep blue to brown in the solid state. The decomposition mechanism and thermal stability of the solid complexes are interpreted in terms of their structures. The final decomposition products – the respective metal oxides – were identified by IR spectroscopy.     

cis-bis(Saccharinato)cobalt(II) and -zinc(II) complexes with 2-dimethylaminoethanol: syntheses,crystal structures,spectroscopic and thermal studies

2-Dimethylaminoethanol (dmea) reacted with tetraaqua-bis(saccharinato)cobalt(II) and -zinc(II) in n-butanol to yield the new complexes cis-[Co(sac)₂(dmea)₂] (1), and cis-[Zn(sac)₂(dmea)₂] (2) (sac?=?saccharinate). The complexes were characterized by elemental analyses, IR spectroscopy, DTA-TG and X-ray crystallography. Both complexes are isomorphous and crystallize in the monoclinic space group P2₁/c. The cobalt(II) and zinc(II) ions are coordinated by two neutral dmea ligands and two sac anions in a distorted octahedral environment. The dmea ligand acts as a bidentate N, O donor through the amine N and hydroxyl O atoms, while the sac ligand exhibits non-equivalent coordination, behaving as an ambidentate ligand; one coordinates to the metal via the carbonyl oxygen atom, while the other is N-bonded. The packing of the molecules in the crystals of both complexes is achieved by aromatic π(sac)–π(sac) stacking interactions, C–H?·?π interactions and weak intermolecular C–H?·?O hydrogen bonds involving the methyl groups of dmea and the sulfonyl oxygen atoms of the sac ligands. IR and UV spectra and thermal analysis are in agreement with the crystal structures.     

Synthesis and characterization of some new cobalt(II) and nickel(II) ternary complexes of <Emphasis Type="Italic">N</Emphasis>-acetyl, <Emphasis Type="Italic">N</Emphasis>-benzoyl and <Emphasis Type="Italic">N</Emphasis>-tosyl derivatives of amino acids

A series of some new cobalt(II) and nickel(II) ternary complexes of N-(acetyl)phenylalaninate (acphe), N-(acetyl)tyrosinate (actyr), N-(benzoyl)leucinate (bzleu), N-(benzoyl)phenylalaninate (bzphe), N-(tosyl)glutamic acid (tsglu), N-(tosyl)arginine (tsarg) with certain N-heterocyclic ligands such as imidazole (imi), methylimidazole (mimi), 2,2′-bipyridyl (bipy) 1,10-phenanthroline (phen) have been synthesized and characterized by elemental analyses, IR and electronic spectra. as well as thermogravimetry. The structure of the cobalt(II) N-phthaloylglycinate complex was also characterized by X-ray single crystal. It was found that the cobalt atom coordinates a 1,10-phenanthroline molecule and four water oxygen atoms, forming a distorted octahedral conformation. A molecule of N-phthaloylglycinate is connected by van der Waals contact and H-bonds.     

The mononuclear cobalt(II) complex CoII(DMBDIZ)2(NCS)2, where DMBDIZ is 2,6‐di­methyl­benzo[1,2‐d:4,5‐d′]­di­imidazole

In the title mononuclear cobalt complex, bis(2,6‐di­methyl‐1H,7H‐benzo­[1,2‐d:4,5‐d′]­di­imidazole‐κN³)­bis­(thio­cyanato‐κN)cobalt(II), [Co^II(NCS)₂(DMBDIZ)₂] or [Co(NCS)₂(C₁₀H₁₀N₄)₂], the cobalt(II) ion is coordinated to four N atoms, from two thio­cyanate anions and two DMBDIZ ligands, in a distorted tetrahedral geometry. In the DMBDIZ ligand, the two imine N atoms are positioned cis with respect to one another. The crystal packing of the complex is dominated by both hydrogen bonding, involving two N—H?N and two N—H?S interactions, and aromatic π–π stacking.     

Synthesis and characterization of 2,3-bis(hydroxyimino)-1,2,3,4-tetrahydro-pyrido[2,3-b]pyrazine and its nickel(II), cobalt(II), copper(II), palladium(II), cadmium(II) and cobalt(III) complexes

Summary 2,3-Bis(hydroxyimino)-1,2,3,4-tetrahydro-pyrido[2,3-b]pyrazine (H₂L), prepared from 2,3-diaminopyridine and cyanogen-di-N-oxide has been converted into nickel(II), palladium(II), copper(II), cobalt(II), and cobalt(III) complexes (H₂L) with a 12 metal:ligand ratio. The ligands coordinate through the two N atoms, as do most vicinal dioximes. [(LH)Cl(H₂O)Cd], contains a six-membered chelate ring. [Co(HL)₂(L)Cl] has also been prepared using triphenylphosphine, triphenylarsine, thiophene and chloride as axial ligands. The structure of thevic-dioxime and its complexes are proposed on the basis of elemental analysis, i.r.,¹H-n.m.r. and uv-visible measurements.     

Copper(II) and cobalt(II) hydroxypyridinecarboxylates: Synthesis, crystal structures, spectral and magnetic properties

Synthesis and characterization of six copper(II) and cobalt(II) octahedral complexes [M(6-OHpic)₂(H₂O)₂] (6-OHpic is 6-hydroxypicolinato), [M(2-OHnic)₂(H₂O)₂] (2-OHnic is 2-hydroxynicotinato), [Cu(6-OHnic)₂(H₂O)₂] (6-OHnic is 6-hydroxynicotinato) as well as [Co(H₂O)₆](6-OHnic)₂ are reported. Their characterization was carried out using elemental analysis, infrared, and magnetic measurements. Based on IR spectra, N,O-coordination of 6-OHpic (via the oxygen atom of the carboxyl group and the nitrogen atom of the pyridine ring), O,O-asymmetrically chelating coordination of the carboxyl groups as well as ionic coordination of 6-OHnic and chelating O,O-coordination (through the oxygen atom of the carboxyl group and the oxygen atom of the amide group) of keto(amide) tautomer of 2-OHnic were supposed. Moreover, crystal structures of 2-OHnicH and the complex [Co(2-OHnic)₂(H₂O)₂]) were determined by X-ray single crystal structure analysis. The system of hydrogen bonds predominantly stabilizes the keto(amide) tautomer of both 2-hydroxynicotinic acid and 2-OHnic anion in the cobalt(II) complex. Intermolecular hydrogen bonds (between the oxygen atom of the amide group and the hydrogen atom of the NH group) interconnect two neighbouring molecules of 2-OHnicH forming dimers. Cobalt(II) in complex [Co(2-OHnic)₂(H₂O)₂] has nearly a regular compressed tetragonal bipyramidal arrangement. Presented at the 1st International Conference “Applied Natural Sciences” on the occasion of the 10th anniversary of the University of Ss. Cyril and Methodius, Trnava, 7–9 November 2007.     

Crystal structure of {aquaimidazole-[2-(2-carbamoylhydrazone)-propionato]} copper(II) nitrate

The crystal structure of {aquaimidazole[2-(2-carbamoylhydrazone)-propionato]}copper(II) nitrate [Cu(L)Im(H₂O)]NO₃ (I), where HL is the semicarbazone of pyruvic acid, Im is imidazole, is dtermined. The crystal structure of I contains two independent complexes IA and IB in which copper atoms coordinate once deprotonated tridentate HL, imidazole, and water molecules. Outer spheres of the complexes contain nitrate ions. In the compounds studied the coordination polyhedron of the copper atom is a distorted tetragonal pyramid. Its base is composed of carboxyl and carbamide oxygen atoms, azomethine nitrogen of monodeprotonated HL molecules, and the imidazole nitrogen atom. In the crystal, nitrate ions and imidazole molecules link the complexes via hydrogen bonds into 2D networks parallel to the (010) plane. These networks in turn are in pairs arranged into layers along the [010] direction due to hydrogen bonds between water molecules and oxygen atoms of nitrate ions, and also by water molecules and O3 atoms of the neighboring 2D networks. In the crystal, the π-π stacking interaction is observed between the imidazole rings from different layers and there is also a N-O…Cg (π ring) interaction inside the layers.     

Complexation of cobalt(II) perchlorate with crown ethers. Synthesis,properties and structure of complexes of cobalt(II) perchlorate with 16-crown-5 and its lariat derivatives

Complexes of cobalt(II) perchlorate with 16-crown-5 (L¹) and its two lariat derivatives, 15,15-dimethyl-16-crown-5 (L²) and 15-(2,5-dioxahexyl)-15-methyl-16-crown-5 (L³), have been prepared and characterized. The crystal structure of [Co(L³)H₂O)](ClO₄)_{_2} has been determined by X-ray crystallography. The cobalt(II) ion is heptacoordinated with five crown ether oxygen atoms at the equatorial plane, a side arm oxygen atom and a water molecule at the apical position. The coordination polyhedron of cobalt is a distorted pentagonal bipyramid with the average Co-O(crown) distance of 2.20(2)Å.     

Synthesis and Spectroscopic Characterization of New Lead(II) Thiosaccharinates. Molecular Structure of Bis(thiosaccharinato)tetrakis(pyridine)dilead(II) and Thiosaccharinato‐bis(1,10‐phenantroline)lead(II) Thiosaccharinate

Four new lead(II) thiosaccharinate complexes: [Pb(tsac)₂H₂O] (1) (tsac: thiosaccharinate anion), [Pb₂(tsac)₄(py)₄] (2) (py: pyridine), [Pb(tsac)(o‐phen)₂](tsac)·CH₃CN (3) (o‐phen: 1,10‐phenantroline), and [Pb(tsac)₂(bipy)] (4) (bipy: 2,2′‐bipyridine) were prepared. The infrared and electronic spectra as well as the thermal analysis of all the compounds were recorded and discussed. The thiosaccharinate anion acts in three different coordination forms, one of then reported for the first time. The crystal structures of complexes 2 and 3 have been determined by single crystal X‐ray diffractometry. In complex 2 , two monomeric moieties are joined together forming a symmetric bis‐μ‐sulphur bridged dimer by interaction of two lead(II) atoms through the exocyclic sulphur atoms of two thiosaccharinate ligands. The seven‐fold coordination sphere of each lead atom is completed by two pyridine nitrogen atoms and by another sulfur and two nitrogen atoms of the thiosaccharinate anions. In complex 3 , the lead(II) atom is coordinated by four nitrogen atoms of two 1,10‐phenantroline molecules and by the sulfur and nitrogen atoms of one thiosaccharinate ion. The second anion has an electrostatic interaction with the nucleus.     

Synthesis,Spectra, Thermal Analysis and Crystal Structure of Trans-Bis(2-Pyridinepropanol)Bis (Saccharinato)Cobalt(II)

The title complex, [Co(pypr)₂(sac)₂] (pypr = 2-pyridinepropanol and sac = saccharinate), has been prepared and characterized by elemental analysis, electronic and FTIR spectra, magnetic susceptibility measurements, thermal analysis and X-ray diffractometry. The complex crystallizes in triclinic space group PI with a = 8.1836(2), b = 10.0062(2), c = 10.4989(3) Å, α = 90.474(1), β = 107.989(1) and γ = 110.923(1)°. The cobalt(II) ion sits on a center of symmetry and is octahedrally coordinated by two pypr and two sac ligands. Both pypr and sac ligands occupy the trans positions of the coordination octahedron. The two pypr ligands are neutral and act as bidentate N- and O-donor ligands forming two symmetry-related seven-membered chelate rings around the cobalt(II) ion, while both sac ligands are O-coordinated through the carbonyl oxygen atoms. On heating the endothermic removal of two pypr ligands occurs in the first stages of decomposition and at higher temperatures the Co/sac intermediate decomposes to Co₃O₄ and finally to CoO.     

Three New Iron(II) Thiocyanato Coordination Polymers Based on 4,4′‐Bipyridine as Ligand and the Influence of Methanol on Their Structures

Reaction of iron(II) thiocyanate with 4,4‐bipyridine (bipy) in methanol leads to the formation of three new solvates of different composition depending on the reaction conditions: At room temperature two new ligand‐rich 1:2 (1:2 = ratio between metal and N‐donor ligand) polymorphic forms [Fe(NCS)₂(bipy)₂ · 2MeOH]_n ( 1I ) and [Fe(NCS)₂(bipy)(MeOH)₂ · (bipy)]_n ( 1II ) are obtained, whereas solvothermal conditions leads to the formation of the new ligand‐deficient 1:1 compound [{Fe(NCS)₂(bipy)(MeOH)}₂]_n ( 2 ). All crystal structures were determined by X‐ray single crystal structure analysis. In the crystal structure of modification 1I the metal atoms are coordinated by four bridging bipy ligands, which connect them into layers. The methanol molecules occupy voids in the structure. Compared to 1I in modification 1II the crystal structure contains of linear Fe–bipy–Fe chains, which are further connected by hydrogen bonds between coordinating MeOH and noncoordinated bipy ligands into layers. The ligand‐deficient 1:1 compound 2 shows a completely different coordination topology with linear Fe–bipy–Fe chains, which are connected by coordinating methanol molecules into double‐chains. In all compounds the thiocyanato anions are terminal N‐bonded to the metal atoms. Investigation of the thermal behavior of compound 1I shows a two‐step decomposition, in which ligand‐deficient intermediates are formed. Magnetic measurements on 1I reveal Curie–Weiss paramagnetism with increasing antiferromagnetic interactions on cooling.     

A novel cobalt(II) coordination polymer containing the fumarate anion and o‐phenanthroline

The self‐assembly of three crystallographically distinct fumar­ate ions, two unique cobalt(II) ions and two unique o‐phen­;anthroline mol­ecules results in a two‐dimensional polymeric structure with the formula [Co₂(C₄H₂O₄)₂(C₁₂H₈N₂)₂]_n, namely di‐μ‐fumatato‐bis(o‐phenanthroline)­dicobalt(II). The Co atoms are at the nodes of a two‐dimensional array linked by coordinated fumarate ligands. Each Co atom is coordinated in a distorted octahedral manner to four fumarate O atoms and two N atoms from the chelating phenanthroline ligands.     

Synthesis of new Cu(II), Ni(II) and Co(II) complexes with a bis-amide ligand functionalized with pyridine moieties: Spectral, magnetic and electrochemical studies

Three new copper(II), nickel(II) and cobalt (II) dinuclear complexes with a bis-amide ligand derived from tartaric acid have been prepared and characterized. For this purpose, the ligand (R,R)-(+)-di-N,N′-methylpyridino-tartramide (dmpt) was synthesized via the classical aminolysis of (R,R)-(+)-dimethyltartrate with pyridylmethylamine. The molecular structures of the complexes Na[Cu₂(dmptH₋₃)(CO₃)] · 8H₂O (1) and [Ni₂(dmptH₋₂)₂] · 9.75H₂O (2) were elucidated by X-ray diffraction, and the complex [Co₂(dmptH₋₃)(μ-OH)] · NaClO₄ · 5H₂O (3) by XAS. The crystal structure of (1) shows that the two metallic centres are in a square planar environment. Each copper(II) is bound to pyridyl and deprotonated amidic nitrogen atoms and to the oxygen atoms of hydroxyl and carbonato groups. In complex (2), both nickel atoms are in a distorted octahedral environment with an identical set of donors atoms, N₄O₂, coming from four nitrogen atoms of two pyridylmethylamido moieties and two oxygen donor atoms of alcohol groups. XAS analysis of complex (3) allows us to propose a CoN₂O₄ chromophore, with two nitrogen atoms coming from pyridyl and amidic groups and two bridged oxygen atoms from a deprotonated alcohol group and an hydroxyl group; the hexacoordination is achieved by two water molecules. The spectroscopic, electrochemical and magnetic properties of these complexes were investigated.     

Synthesis,Crystal Structure and Characterization of Polynuclear Potassium(I), Copper(II) and Cobalt(II) Complex with Acetylacetonethylenediamine

The title complex [K{Cu(acen)}₃]₂[Co(NCS)₄]·1/4CH₃OH (acen = acetylacetonethylenediamine anion) has been prepared and characterized. Single-crystal x-ray analysis reveals that the complex crystallizes in space group P I with a = 11.442(2), b = 15.098(3), c = 28.500(4) Å, α = 82.77(1), β = 83.58(1), γ = 85.07(1)°. The crystal consists of the complex [K{Cu(acen)}₃]⁺ cations, [Co(NCS)₄]^2? anions and methanol molecules. Three [Cu(acen)] molecules function as bridging ligands through phenolic O atoms to one K⁺ to give the tetranuclear [K{Cu(acen)}₃]⁺ cation. Each copper(II) atom in the cation is in a square-planar geometry, being coordinated by two oxygen atoms and two nitrogen atoms from a quadridentate acen ligand. The cobalt(II) atom is coordinated by four nitrogen atoms of thiocyanate ligands, forming a deformed tetrahedral environment. The IR and UV-Vis spectra have also been investigated.     

Synthesis and structure of complexes of Co(II) acetate and Zn(II) chloride with 2-aminobenzothiazole

Complexes of Co(II) acetate and Zn(II) chloride with 2-aminobenzothiazole were prepared, and their structures were studied by IR spectroscopy and single crystal X-ray diffraction. The complexes have the composition [Co(CH₃COO)₂(2-aminobenzothiazole)₂] and [Zncl₂(2-aminobenzothiazole)₂]. The coordination core has a distorted tetrahedral configuration. The metal ion coordinates two nitrogen atoms of the thiazole rings and two oxygen atoms of acetate ligands or two chloride ions.     

Two isomorphous imidazole (Him) complexes: [MCl2(Him)2(H2O)2] (M = Co and Ni)

The structures of aqua­di­chloro­bis(1H‐imidazole)­cobalt(II), [CoCl₂(Him)₂(H₂O)₂] (Him is 1H‐imidazole, C₃H₄N₂), (I), and aqua­di­chloro­bis(1H‐imidazole)­nickel(II), [NiCl₂(Him)₂(H₂O)₂], (II), are isomorphous and consist of monomers with inversion symmetry. The three monodentate ligands (imidazole, chlorine and aqua), together with their symmetry equivalents, define almost perfect octahedra. Hydro­gen‐bonding interactions via the imidazole and aqua H atoms lead to a three‐dimensional network.