Synthesis and structure of new thiourea-containing Cobalt(III) dioximates with the [TiF6]2− anion

The new Co(III) dioximates [Co(DH₂)(D)(Thio)₂]₂[TiF₆] ·2DMF (I), [Co(NioxH)₂(Thio)₂]₂[TiF₆] · 2.25H₂O (II), and [Co(DpgH)₂(Thio)₂]₂[TiF₆] · 4DMF · 1.5H₂O (III) have been synthesized and studied (DH₂ and D are, respectively, the dimethylglyoxime molecule and doubly charged anion; NioxH and DpgH are singly charged anions of 1,2-cyclohexanedione dioxime and diphenylglyoxime, respectively; Thio is thiourea; DMF is dimethylformamide). The composition and structure of the complexes have been studies by IR, UV, and NMR spectroscopy. The crystal structures have been determined by X-ray crystallography. The hydrogen bonds in the structures are formed by fluorine atoms of the [TiF₆]^2? anion with Co(III) complex cations and solvent molecules of crystallization. The amino groups of coordinated thiourea molecules are also involved in the hydrogen bond system, which is responsible for their different arrangement with respect to the equatorial planes of the Co(III) complex cations.     

Dicarbonylcyclopentadienyltellurophenyliron complexes as ligands

The reaction of CpFe(CO)₂TePh (I) with ferricinium hexafluorophosphate as an oxidant affords ionic complex {[CpFe(CO)₂]₂(μ-TePh)}⁺PF ₆ ^? (II) with the simultaneous formation of diphenylditellurium. The decarbonylation of compound II by Me₃NO followed by the addition of complex I affords trinuclear complex {[CpFe(CO)₂(μ-TePh)]₂Fe(CO)Cp}PF₆ (III). The corresponding tetrafluoroborate (IV) is synthesized similarly. The heating of compound I with PPh₃ gives CpFe(CO)(PPh₃)TePh (V) that reacts with ionic complex [CpMn(CO)₂(NO)]PF₆ (VI) to form binuclear heterometallic ionic complex [CpFe(CO)(PPh₃)(μ-TePh)Mn(CO)(NO)Cp]PF₆ (VII). A similar reaction of Cp′Fe(CO)₂TePh (Cp′ is methylcyclopentadienyl) with compound VI affords heterometallic [Cp′Fe(CO)₂(μ-TePh)Mn(CO)(NO)Cp]PF₆ (VIII). The structures of compounds II, IV, VII, and VIII are determined by X-ray diffraction analysis (CIF files CCDC 963285, 963286, 963288, and 963289, respectively).     

Synthesis and crystal structures of two new Schiff base cobalt(II) and nickel(II) complexes

The Schiff base ligand (HL) obtained from phenylmethanamine and 5-methoxysalicylaldehyde are used as ligands for Co(II) and Ni(II) resulting in complexes [Co(L)₂] (I) and [Ni(L)₂] (II), and their solid state structures were determined by X-ray crystallography. In both complexes, weak interactions play an important role in the molecular self-assembly. Complex I was stacked up to the 2D layers by C-H…O hydrogen bonds and C-H…π interactions. In contrast, complex II was extended into 2D sheet by C-H…O hydrogen bonds, the C-H…π interactions, and edge-to-face interactions.     

Heterometallic complexes of macrocyclic oxamide with polycarboxylates: Syntheses,crystal structures,and magnetic properties

Three complexes with the formula [Co(Ip)(CuL)(H₂O)₂] · H₂O (I), [Co(Ip)(NiL)(H₂O)₂] · H₂O (II), [Co(CuL)₂(Hbtc)(H₂O)] (III), (H₂Ip = m-isophthalic acid; H₂L = 2,3-dioxo-5,6,14,15-dibenzo-1,4,8,12-tetraazacyclo-pentadeca-7,13-dien; H₃Btc = 1,3,5-benzenetricarboxylic acid) were synthesized and structurally characterized by elemental analysis, IR and UV spectroscopy. Single-crystal X-ray analyses reveal that the complexes I and II contain neutral heterometallic binuclear CoM (for I and II, M = Cu, Ni, respectively) moieties, and complex III contains discrete neutral trinuclear CoCu₂ moieties. The structures of I–III consist of two-dimensional supramolecular architecture formed by strong O-H…O intermolecular hydrogen bonds. Furthermore, the magnetic properties of complex I were investigated and discussed in detail.     

Synthesis and study of tetraamminecobalt hydrogen hexamolybdometalates(III)

Tetraamminecobalt hydrogen hexamolybdoferrate [Co(NH₃)₄] · H[FeMo₆O₁₈(OH)₆] · 6H₂O (I) and tetraamminecobalt hydrogen hexamolybdogallate(III) [Co(NH₃)₄] · H[GaMo₆O₁₈(OH)₆] · 6H₂O (II) were synthesized and studied by mass spectrometry, thermogravimetry, IR spectroscopy, and X-ray diffraction. Crystals of I and II are monoclinic; a = 16.21 Å, b = 5.43 Å, c = 12.32 Å, β = 119.63°, V = 1092.11 ų, ρ_calcd = 2.21 g/cm³, and Z = 1 for I; a = 16.24 Å, b = 5.59 Å, c = 12.29 Å, β = 119.79°, V = 1064.05 ų, ρ_calcd = 2.15 g/cm³, and Z = 1 for II. Compounds I and II were used as catalysts for soft oxidation of natural gas.     

Complexes of Cu(II) and Co(II) nitrates with 3-Phenyl-5,5-dimethyl-5,6-dihydro-1,2,4-triazolo[3,4-a]isoquinoline

Complexes of Cu(II) and Co(II) nitrates with 3-phenyl-5,5-dimethyl-5,6-dihydro-1,2,4-triazolo[3,4-a]isoquinoline (L⁰) of the composition [CuL ₂ ⁰ (NO₃)₂] (I) and [CoL ₂ ⁰ (NO₃)₂] · CH₃CN (II) are synthesized and their crystal structures are determined by X-ray diffraction. The L⁰ ligand is coordinated to the metal atoms through the N atom in position 2 of triazole fragment. The coordination polyhedron of the Cu(II) atom is a square with two additional axial vertices, while that of the Co(II) atom is a tetrahedron with two additional vertices. The NO ₃ ^? groups in the structures of I and II perform similar anisobidentate function. Complexes I and II are studied by IR and electronic spectroscopy.     

Tansition metal complexes with 2-(1-(carboxymethyl)-2-methyl-1H-benzimidazol-3-ium-3-yl)acetate (HL): Synthesis and crystal structure of [Co(L)2(H2O)4] · 6H2O and [Cu(L)2(H2O)2] · 4H2O

Transition metal complexes of 2-(1-(carboxymethyl)-2-methyl-1H-benzimidazol-3-ium-3-yl)acetate (HL), namely [Co(L)₂(H₂O)₄] · 6H₂O (I) and [Cu(L)₂(H₂O)₂] · 4H₂O (II), have been synthesized by a hydrothermal procedure and characterized by X-ray crystallography, CIF files CCDC nos. 1007524 (I), 1007525 (II). Both I and II are mononuclear molecules. In I, the Co²⁺ ion is in octahedral coordiantion environment and surrounded by four O atoms from water molecules and two carboxylate O atoms of two deprotonated ligand (L^?) occupied six culmination. While in II, the Cu²⁺ ion is located in a square-planar geometry, bounded to two aqua O atoms and two carboxylate O atoms from L^?.     

Synthesis and crystal structure of Co(III) dioximates with the complex anion [SbF6]?

The complexes [Co(DioxH)₂L₂][SbF₆] · nH₂O, where DioxH is dimethylglyoxime monoanion (DioxH^?) or 1,2-cyclohexanedione dioxime (NioxH^?), L is aniline (An) or triphenylphosphine (PPh₃), were isolated from the CoX₂ · nH₂O-NaSbF₆-DioxH₂-L system (X = F or CH₃COO) in aqueous methanol. The complexes were studied by UV, IR, and NMR spectroscopy and by X-ray diffraction. The crystal structure of [Co(DH)₂(An)₂][SbF₆] · H₂O (I) and [Co(NioxH)₂(PPh₃)₂][SbF₆] (II) is stabilized by the electrostatic interactions between the Co(III) complex cations and outer-sphere fluorine-containing anions and by hydrogen bonds between structural units.     

Effect of heterometallic biscitratogermanates (-stannates) of Co(II) and Ni(II) on the polycondensation and properties of poly(glycol maleate phthalate) copolymers

The ability of heterometallic Ge(IV) and Sn(IV) complexes [Co(H₂O)₆][Ge(HCitr)₂] (I), [Co(H₂O)₆] [Sn(HCitr)₂] (II), [Ni(H₂O)₆][Ge(HCitr)₂] (III), [Ni(H₂O)₆][Sn(HCitr)₂] (IV), [Mg(H₂O)₆][Ge(HCitr)₂] (V), and [Mg(H₂O)₆][Sn(HCitr)₂] (VI) (H₄Citr is citric acid) to activate polycondensation of maleic and phthalic anhydrides with ethylene glycol was studied. Copolymerization of modified poly(glycol maleate phthalate) with triethylene glycol dimethacrylate was performed, and the copolymer characteristics were determined.     

Octahedral cluster Mo complexes (Bz3NH)3[Mo6OCl13] and (Bz3NH)2[Mo6Cl14] · 2CH3CN: Synthesis, crystal structure and properties

The salts (Bz₃NH)₃[Mo₆OCl₁₃] (I) and (Bz₃NH)₂[Mo₆Cl1₄] · 2CH3CN (II) were obtained by reacting melted tribenzylamine with cluster Mo compounds. Compound II contains a known cluster anionic complex [Mo₆Cl₁₄]^2?. Compound I includes novel cluster anionic complex [Mo₆OCl₁₃]^3?, where one internal Cl atom is replaced by the O atom. Complex II exhibits phosphorescence in a long-wavelength region of visible spectrum.     

Synthesis and study of hydrogen hexamolybdonickelate and hydrogen hexamolybdozincate with the cobaltammine cation

[Co(NH₃)₆] · H₂[NiMo₆O₁₈(OH)₆] · 6H₂O (I) and [Co(NH₃)₆] · H₂[ZnMo₆O₁₈(OH)₆] · 6H₂O (II) have been synthesized and studied by mass spectroscopy, thermogravimetry, and X-ray powder diffraction. The crystals of compounds I and II are monoclinic, Z = 1; for compound I: a = 16.10 Å, b = 5.58 Å, c = 12.22 Å, β = 117.86°, V = 1045.14 ų, and ρ_calcd = 2.26 g/cm³; for compound II: a = 16.12 Å, b = 5.52 Å, c = 12.12 Å, β = 117.90°, V = 1043.21 ų, and ρ_calcd = 2.21 g/cm³.     

Asymmetric and symmetric cobalt(III) dioximates with pyrazinecarboxamide: Synthesis and crystal structure

A number of novel complexes of cobalt(III) trans-dioximates containing pyrazinecarboxamide were obtained: [CoBr(DfgH)₂(Pzca)] · 0.125H₂O (I), [CoCl(NioxH)₂(Pzca)] (II), [CoCl(DmgH)(NioxH)(Pzca)] · 0.5C₂H₅OH · 0.5H₂O (III), and [CoCl(DmgH)₂(Pzca)] (IV), where DmgH, DfgH, and NioxH are the monoanions of dimethylglyoxime, diphenylglyoxime, and cyclohexane-1,2-dione dioxime, respectively; Pzca is pyrazinecarboxamide. Complexes I?CIII were examined by X-ray diffraction. In these complexes, the Co(III) atom has an octahedral environment with the pseudomacrocyclic fragment (DioxH)₂ in the equatorial plane (DioxH is the ??-dioxime residue). The latter is stabilized by hydrogen bonds O-H?O. In all the complexes, the organic ligand is monodentate and coordinated through one N atom of the heterocycle so that it is trans to the halide anion.     

Coordination compounds with the general formula trans-[M(18-crown-6)(C5HO2F6)2] as structural-thermochemical analogs. The complexes trans-[Pb(18-crown-6)(C5HO2F6)2] and trans-[Ba(18-crown-6)(C5HO2F6)2]

The molecular geometries of the complexes trans-[M(18-crown-6)(C₅HO₂F₆)₂] (where M = Ca, Sr, Ba (I), Zn, Cd, Sn, Pb (II), Fe, Co, Eu, and Yb) were modeled by the molecular mechanics method with fixed R(M-O) distances. The shielding degrees of the central metal atom in these complexes were calculated and the number and types of possible intermolecular contacts between their molecules in the structure were determined. The intermolecular interactions involve identical fragments (atoms) of the ligands: the CF₃ groups of the hexafluoroacetylacetonate ligands and the methylene fragments of the crown ether. Previously unknown complex II and complex I were synthesized according to an original procedure. The structure and thermochemical properties (including sublimation by the Knudsen method) of complex II were studied. As in complex I, the metal cation in complex II is in the cavity of the macrocycle of the crown ether; the hexafluoroacetylacetonate ligands are trans relative to that cation. The presumed similarity of complexes I and II in thermochemical characteristics was confirmed experimentally. Both the complexes melt in close temperature intervals and sublime at the same temperature (～10^?2 mm Hg) without decomposition. The enthalpies of sublimation of complexes I and II, as well as the entropy contributions to their volatilities, are equal to within the experimental error.     

Synthesis and Structure of Co(III) Complexes with 2-Pyridinecarboxylic Acid

The Co(III) complexes with pyridinecarboxylic acid, Na[Co(Pc)₂(NO₂)₂] (I) and NH₄[Co(Pc)₂(NO₂)₂] (II), where Pc is the 2-pyridinecarboxylate anion, have been synthesized and studied by X-ray diffraction. In the crystal, the complex anions are combined through the Na⁺ and NH ₄ ⁺ cations. In II, the anion and the cation are combined by hydrogen bonds.     

Crystal structure,thermal behavior,and microbiological activity of a thiosemicarbazide-type ligand and its cobalt complexes

The synthesis of a potentially bioactive mixed-valence Co^III/Co^II complex with 2-acetylpyridine S-methylisothiosemicarbazone (HL) ligand is described. The crystal and molecular structure of the formed [Co^IIIL₂][Co^IICl₃ py]·Me₂CO (I) compound (py stands for pyridine) is determined by single-crystal X-ray crystallography. It’s thermal decomposition along with the decomposition of the ligand and six structurally related complexes with formulas [CoL₂]NO₃·MeOH (1), [CoL₂]Br·MeOH (2), [CoL₂]HSO₄·MeOH (3), [CoL₂]₂[Co^II(NCS)₄] (4), [Co(HL)(L)]I₂·2MeOH (5), and [Co(HL)(L)][Co^IICl₄]·MeOH (6) was determined by simultaneous TG/DSC measurements. The decomposition pattern is evaluated using TG/DTA-MS data. The results were related to the solvent/moisture content and the decomposition mechanism of the compounds. The antimicrobial activity of the ligand and of all the complexes was tested in vitro for selected gram-negative and gram-positive bacteria and fungi. The activity of the ligand against all tested bacteria is comparable with those obtained for standard antibiotics, while it is less active against fungi. Surprisingly, the activity of the complexes is very low. The low antimicrobial activity of the complexes may be in connection with their high thermodynamic and kinetic inertness in solution. The results are also supported by the relatively high thermal stability of the complexes.     

Synthesis and crystal structures of the Zn(II) and Co(II) complexes containing the reduced derivative nitronyl nitroxide

Two complexes of formulas [Zn(Hfac)₂(IM-IMH-Bph)] (I) and [Co(Hfac)₃](IM-Bph) (II), where IM-Bph = 2,2′-bis(1′-oxyl-4′,4′,5′,5′-tetramethylimidazoline-2′-yl)-bis(2-formylphenyl) ether; Hfac = hexafluoroacetylacetonate, have been synthesized and characterized by single-crystal X-ray diffraction. The X-ray analysis demonstrates that both I and II are mononuclear complexes. In I, each zinc ion is five-coordinated with four oxygen atoms from two Hfac ligands and one oxygen atom from nitroxide. Complex II contains one Co(III) atom with six oxygen atoms from three Hfac ligands and uncoordinated IM-Bph diradical, in which the Co²⁺ ion and NIT-Bph biradical can undergo the redox reaction.     

Adduct formation of cadmium(II) N,N-cyclo-hexamethylenedithiocarbamate, [Cd2{S2CN(CH2)6}4], with morpholine: Synthesis, molecular structure, and thermal behavior of a crystalline adduct cis-[Cd{NH(CH2)4O}2{S2CN(CH2)6}2]

The reaction of [Cd₂{S₂CN(CH₂)₆}₄] (I) with morpholine gives a crystalline adduct of cadmium N,N-cyclo-hexamethylenedithiocarbamate [Cd{NH(CH₂)₄O}₂{S₂CN(CH₂)₆}₂] (II), whose coordination sphere includes two molecules of the donor base. The structural organization and thermal behavior of II is studied by X-ray diffraction analysis and simultaneous thermal analysis in comparison with the original binuclear cadmium complex I. The central cadmium atom (coordination number 6) coordinates two morpholine molecules and two structurally equivalent S,S’-anisobidentate ligands HmDtc to form a chromophore [CdN₂S₄] with the structure of a distorted octahedron. The thermal destruction of II proceeds in two stages and includes consecutive steps of dissociation of the Cd-N bonds followed by the desorption of morpholine and thermolysis of the dithiocarbamate moiety of the adduct to form CdS as the final product. The structure of binuclear [Cd₂{S₂CN(CH₂)₆}₄] is refined for a correct refinement of the geometric characteristics of compounds I and II.     

Hydrothermal synthesis, crystal structures, and properties of two Co(II) complexes based on 4-bromoisophthalic acid and N-donor ligands

Two new Co(II) complexes, [Co₂(H₂O)(Bipy)₂(Bript)₂] _n (I) and [Co(H₂O)(Phen)(Bript)] · H₂O (II), where H₂Bript = 4-bromoisophthalic acid, Bipy = 2,2??-bipyridine, and Phen = 1,10-phenanthroline, have been synthesized and characterized by elemental analysis, IR, and single-crystal X-ray diffraction. Complex I has binuclear units in which two Co²⁺ ions are bridged by two carboxylate groups and a coordinaiod-water molecule, and the binuclear units are connected by Bript to generate a 1D helical chain. These 1D helical chains are further linked by ????? stacking interactions to form a 3D supramolecular network, while complex II has a 2D layer motif. In I and II, there exists extensive hydrogen bonding interactions. The thermal behavior of the two corresponding complexes have briefly been investigated.     

Diaquabromo(18-crown-6)rubidium and triaqua(18-crown-6)barium dibromide monohydrate: Synthesis and crystal structures

Two complexes are synthesized: diaquabromo(18-crown-6)rubidium [RbBr(18-crown-6)(H₂O)₂] (I) and triaqua(18-crown-6)barium dibromide monohydrate [Ba(18-crown-6)(H₂O)₃]²⁺ 2Br^? · H₂O (II). The orthorhombic structure of compound I (space group Pnma, a = 10.124 Å, b = 15.205 Å, c = 12.544 Å, Z = 4) and the monoclinic structure of compound II (space group C 2/c, a = 17.910 Å, b = 10.315 Å, c = 14.879 Å, β = 123.23°, Z = 4) are determined by a direct method and refined by the full-matrix least-squares method in the anisotropic approximation to R = 0.063 (I) and 0.042 (II) for all 2293 (I) and 3363 (II) independent measured reflections (CAD-4 automated diffractometer, λMoK _α). The complex molecule [RbBr(18-crown-6)(H₂O)₂] in compound I and the randomly disordered cation [Ba(18-crown-6)(H₂O)₃]²⁺ in compound II are of the host-guest type: their Rb⁺ or Ba²⁺ cation (its coordination number is nine) is located in the cavity of the 18-crown-6 ligand and coordinated by all six O atoms. In structure I, the coordination polyhedron of Rb⁺ is a distorted hexagonal pyramid with a triple apex at the Br^? ligand and two O atoms of the water molecules. In structure II, the Ba²⁺ polyhedron is a distorted hexagonal bipyramid with one apex at the O atom of the water molecule and the other split apex at two O atoms of water molecules.     

Synthesis and Structure of Different-Metal Different-Ligand Germanium(IV) and Cobalt(II) or Copper(II) Complexes with 1-Hydroxyethylidenediphosphonic Acid and 1,10-Phenanthroline

Different-metal different-ligand complexes [{Co(Phen)₃}₂{Co(Phen)(H₂O)₄}₂][{Ge(μ-OH)(μ- Hedp)}₆Cl₂] (I), [{Cu(Phen)₂(H₂O)}₂(HPhen)₂][Ge(μ-OH)(μ-Hedp)]₆ · 20H₂O (II) (H₄Hedp = 1-hydroxyethylidenediphosphonic acid, Phen = 1,10-phenanthroline) were synthesized and studied by X-ray diffraction. According to X-ray diffraction data (CIF files CCDC nos. 1573112 (I), 1573113 (II)), compounds I and II are cation–anion type complexes in which the anions are represented by {[Ge(μ-OH)(μ-Hedp)]⁶}^6– and, in the case of I, two additional Cl^– ions, while the cations are [Co(Phen)₃]²⁺, [Co(Phen)(H₂O)₄]²⁺ in I and [Cu(Phen)₂(H₂O)]²⁺, HPhen⁺ in II. In the crystals of compounds I and II, the cations, anions, and water molecules are combined by numerous intermolecular hydrogen bonds, giving rise to a 3D network.