Showing papers in "Journal of Coordination Chemistry in 2004"
TL;DR: In this paper, the interactions of cephalexin (Hcepha) with transition and d10 metal ions have been investigated by physicochemical and spectroscopic methods.
Abstract: The interactions of cephalexin (Hcepha) with transition and d10 metal ions have been investigated. The complexes [M(cepha)Cl]nH2O [M = Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II)] were characterized by physicochemical and spectroscopic methods. The IR and 1H NMR spectra of the complexes suggest that cephalexin behaves as a monoanionic tridentate ligand. In vitro antibacterial activities of Hcepha and the complexes were tested.
63 citations
TL;DR: In this article, the synthesis, structure, physico-chemical investigation and biological studies of some metal complexes of thiocarbohydrazone ligands are described and preliminary antimicrobial screening showed that the ligands and their metal complexes possess antimicrobial activity towards bacteria and fungi.
Abstract: The synthesis, structure, physico-chemical investigation and biological studies of some metal complexes of thiocarbohydrazone ligands are described. The ligands were obtained by condensation of N,N′-thiocarbohydrazide with carbonyl compounds such as 2-hydroxyacetophenone or 5-chlorosalicylaldehyde. A variety of binuclear or mononuclear complexes were obtained with the ligands in mono-, bi- and/or tri-deprotonated forms. The bonding sites are the azomethine nitrogen atom, phenolic oxygen atom and thiol sulfur atom. The metal complexes exhibit either tetrahedral or octahedral structures. Preliminary antimicrobial screening showed that the ligands and their metal complexes possess antimicrobial activity towards bacteria and fungi.
56 citations
TL;DR: In this paper, the structure of mononuclear Au(III) complexes of the peptides H-His-Met-OH (D) and H-Gly-Gli-Met Met-OH(T) and their N-protected forms Ac-D and Ac-T were structurally characterized by means of IR, MS and NMR.
Abstract: Mononuclear Au(III) complexes of the peptides H-His-Met-OH (D) and H-Gly-Gly-Met-OH (T) and their N-protected forms Ac-His-Met-OH (Ac-D) and Ac-Gly-Gly-Met-OH (Ac-T) were structurally characterized by means of IR, MS and NMR. In the complexes with dipeptides [AuLCl2]Cl (L = D or Ac-D), Au(III) is coordinated through S and imidazole N atoms from methionine and histidine fragments of the ligands forming macrochelate rings at mol ratio Au : L = 1 : 1. Additionally, Au(III) is coordinated by two terminal chloride ions in a square-planar arrangement. In complexes with the tripeptides [AuL′Cl] (L′ = T or Ac-T), however, the metal ion is coordinated in a tridentate fashion, through S and two N atoms, also at mol ratio M : L = 1 : 1. The fourth position of Au(III) is occupied by a Cl− ligand.
44 citations
TL;DR: A lead-II complex of 2,2′-bipyridine (bpy), acetate and thiocyanate has been synthesized and characterized by C H N elemental analysis, IR, 1H N, 13C NMR and 207Pb NMR spectroscopy as mentioned in this paper.
Abstract: A new lead(II) complex of 2,2′-bipyridine (bpy), acetate and thiocyanate has been synthesized and characterized by C H N elemental analysis, IR, 1H NMR, 13C NMR and 207Pb NMR spectroscopy. The structure of [Pb(bpy)(NCS)(CH3COO)] n was confirmed by X-ray crystallography. Single-crystal X-ray data show the complex to be a one-dimensional polymer as a result of thiocyanate ligand bridging with the basic repeating monomeric units [Pb(bpy)(NCS)(CH3COO)]. The Pb atom has an unsymmetrical five-coordinate geometry, being coordinated by two nitrogen atoms of bpy, two oxygen atoms of the acetate and one nitrogen atom of the thiocyanate anion. The arrangement of the bpy, acetate and nitrate ligands exhibits a coordination gap around the Pb(II) ion, occupied possibly by a stereoactive lone pair of electrons on lead(II), and the coordination around the lead atoms is hemidirected. There are π–π stacking interactions between the parallel aromatic rings.
43 citations
TL;DR: In this paper, a series of manganese, nickel, cobalt, copper, and zinc complexes of 2-(acetichydrazido-N-methylidene-α-naphthol)-benzothiazol (H2L) was prepared and characterized by elemental analysis, IR, UV, magnetic susceptibility, thermogravimetric analysis (TGA), molar conductance and ESR measurements.
Abstract: A new series of manganese(II), nickel(II), cobalt(II), copper(II) and zinc(II) complexes of 2-(acetichydrazido-N-methylidene-α-naphthol)-benzothiazol (H2L) was prepared and characterized by elemental analysis, IR, UV–VIS, magnetic susceptibility, thermogravimetric analysis (TGA), molar conductance and ESR measurements. Molar conductances of the complexes in DMF are commensurate with their nonelectrolytic nature. IR spectral data show that the ligand can be bidentate and/or tridentate. ESR spectra of the solid copper(II) Complexes 8 and 9 show a d x2 − y2 ground state with covalent character. The fungicidal activities of the ligand and its metal complexes against Aspergillus niger and Fusarium oxysporum are discussed.
38 citations
TL;DR: In this paper, a single crystal X-ray structure determination revealed that the title complex salt crystallizes in the orthorhombic space group Pnma with a = 18.230(2), b = 8.591(2)
Abstract: Reddish-orange single crystals of hexaamminecobalt(III) chloride selenate trihydrate, [Co(NH3)6]ClSeO4· 3H2O, have been prepared by reacting aqueous solutions of hexaamminecobalt(III) chloride and potassium selenate in a 1 : 1 molar ratio. The salt was characterized by elemental analyses, thermogravimetry, magnetic moment and spectroscopic studies (IR, electronic). A single crystal X-ray structure determination revealed that the title complex salt crystallizes in the orthorhombic space group Pnma with a = 18.230(2), b = 8.591(2), c = 8.593(2) A, V = 1345.9(4) A3, Z = 4, R = 0.0400 and Rw = 0.0980. In the salt the network of hydrogen bonds between the hexaamminecobalt(III) cation, water molecule, chloride and oxygen atoms of the selenate ion represents the second sphere coordination and also suggests that [Co(NH3)6]3+ may be used as an anion receptor for the selenate ion.
38 citations
TL;DR: In this article, a glassy carbon electrode modified with Co(II)-tetrabenzoporphyrin as adsorbed layers or as a supramolecular system was used for the electroreduction of carbon dioxide.
Abstract: The electro-reduction of carbon dioxide was studied by using a glassy carbon electrode modified with Co(II)-tetrabenzoporphyrin as adsorbed layers or as a supramolecular system. In order to obtain the supramolecular electrode, 4-aminopyridine was chemically bonded to the electrodic surface. On this surface, a first layer of porphyrins was anchored by the pyridine as a fifth ligand. Packed on the first layer of porphyrins, a supramolecular system is formed. The electrode modified with physically adsorbed layers of porphyrins does not show catalytic response toward the electroreduction of CO2. However, the supramolecular electrode is very stable and shows a high catalytic response.
38 citations
TL;DR: In this paper, the bimetallic salt hexaamminecobalt(III) chloride molybdate trihydrate, [Co (NH3)6]ClMoO4·3H2O, has been prepared by reacting hot aqueous solutions of hexa-ammincobals and sodium molybdate dihydrate in a 1:1 molar ratio.
Abstract: Orange, single crystals of the bimetallic salt hexaamminecobalt(III) chloride molybdate trihydrate, [Co (NH3)6]ClMoO4·3H2O, have been prepared by reacting hot aqueous solutions of hexaamminecobalt(III) chloride and sodium molybdate dihydrate in a 1:1 molar ratio. The salt was characterized by elemental analyses and spectroscopic studies (IR and electronic). The title complex salt crystallizes in orthorhombic, space group Pnma, with a = 18.408(2), b = 8.672(1), c = 8.661(1) A, V = 1382.6(3) A3, Z = 4 and R = 0.0255. A single-crystal X-ray structure determination revealed the presence of discrete ions [Co(NH3)6]3+, Cl− and and three lattice water molecule in the solid state. The formation of this salt suggests that [Co(NH3)6]3+ may be used as an anion receptor for the molybdate ion.
37 citations
TL;DR: In this paper, a series of new bis(N-aryl-3,5-di-tert-butylsalicylaldiminato)copper(II) complexes (I), prepared from 3-5-detert-Butyl salicylaldehyde and mono-substituted anilines, and their spectroscopic properties as well as electrochemistry and reactivity toward PPh3 are described.
Abstract: A series of new bis(N-aryl-3,5-di-tert-butylsalicylaldiminato)copper(II) complexes (I), prepared from 3,5-di-tert-butylsalicylaldehyde and mono-substituted anilines, X-C6H4NH2(X = H, o-F, Cl, Br, CH3, CH3O; p-F, Cl, Br, CH3, CH3O, t-Bu and 5,6-benzo), and their spectroscopic properties as well as electrochemistry and reactivity toward PPh3 are described. Comparison of g ‖ (2.223–2.249), A ‖ (150–170 G) tensors and the axial symmetry parameter, g ‖/A ‖, (140–155 cm) of I with those of model Cu(II) complexes reveals that the coordination site is distorted from square planar toward tetrahedral geometry. The di-tert-butyl groups on the salicylaldehyde moiety unlike those introduced on the aniline rings do not facilitate reactivity toward PPh3. Electrochemical studies of I in acetonitrile solutions reveal highly irreversible behavior, due to chemical or stereochemical changes subsequent to electron transfer. In the oxidation of some complexes with (NH4)2Ce(NO3)6 in acetonitrile at 300 K, along with decreasing ...
37 citations
TL;DR: In this paper, a single-crystal X-ray diffraction, elemental analyses and IR spectra were used to characterize the H3O complex, which possesses both π-π stacking and hydrogen-bonding interactions for three-dimensional (3D) networks.
Abstract: The novel complex (H3O)2[Cu(2,6-pydc)2]·H2O (pydc = pyridinedicarboxylic acid) (1) has been synthesized in aqueous solution and characterized by single-crystal X-ray diffraction, elemental analyses and IR spectra. X-ray structural analysis revealed that the novel complex possesses both π–π stacking and hydrogen-bonding interactions for three-dimensional (3D) networks. Crystal data for 1: a = 13.454(3), b = 10.266(2), c = 13.783(3) A, α = 90.00, β = 115.29(3), γ = 90.00°, Z = 3, R 1 = 0.0423, wR 2 = 0.1217.
35 citations
TL;DR: In this article, the coordinative properties of synthetically modified carbohydrates to metal cations are reviewed and the influences of complex-formation conditions on chemical properties of modified carbohydrates, as well as on organic reactions (especially diastereoselective ones), are examined.
Abstract: The coordinative properties of synthetically modified carbohydrates to metal cations are reviewed. Such metal complexes are distinct, owing to the structural diversity of the ligands and coordination modes. The influences of complex-formation conditions on chemical properties of modified carbohydrates, as well as on organic reactions (especially diastereoselective ones), are examined. In addition, this manuscript demonstrates the practical importance of the coordination interactions.
TL;DR: Three Keggin-type polyoxometalates functionalized by amino acids were synthesized and characterized by elemental analysis, IR and 1H NMR spectra and single-crystal X-ray diffraction as mentioned in this paper.
Abstract: Three Keggin-type polyoxometalates functionalized by amino acids, (C5H13N2O2)2(H3O)PMo12O40·8H2O 1, (C5H14N2O2)2SiMo12O40·12H2O 2 and (C5H14N2O2)2GeMo12O40·12H2O 3, were synthesized and characterized by elemental analysis, IR and 1H NMR spectra and single-crystal X-ray diffraction. The X-ray crystallographic study showed that the structures of the three compounds involved N–H···O and O–H···O hydrogen bonds among the protonated ornithine cations, water molecules and the heteropolyanion cluster, and thus represent a model interaction between polyoxometalates and proteins. These complexes display inhibitory actions to the human cancer cells Hela and PC-3 m in vitro.
TL;DR: Several new complexes of Schiff bases obtained by the condensation of 1,2-bis(p-aminophenoxy)ethane and 1, 2-bis (m-, 3-di-tert-butyl-2-hydroxybenzaldehyde have been synthesized, and characterized by elemental analyses, FT-IR, UV-VIS, 1H NMR spectroscopy, magnetic susceptibility measurements and cyclic voltammetry as mentioned in this paper.
Abstract: Several new complexes of Schiff bases obtained by the condensation of 1,2-bis(p-aminophenoxy)ethane and 1,2-bis(m-aminophenoxy)ethane with 3,5-di-tert-butyl-2-hydroxybenzaldehyde have been synthesized, and characterized by elemental analyses, FT-IR, UV–VIS, 1H NMR spectroscopy, magnetic susceptibility measurements and cyclic voltammetry. The metal to ligand ratios of the Co(II) and Cu(II) complexes were found to be 1 : 1. The coordination of the Schiff base appears to occur through the two azomethine nitrogens and two o-OH groups. Electrochemical data suggest the existence of copper(II)/copper(I) and cobalt(II)/cobalt(I) redox couples in DMSO along with an irreversible oxidation peak assigned to the oxidation of ligands for all of the complexes.
TL;DR: In this article, the synthesis and characterization of [Cu(CH3CCl2CO2)2(3mpyc)2] (1) (3-MPyc = methyl-3-pyridyl carbamate) and [Cu (CH3CHBrCO2]2(2-pyme)2 ] (2) (2pyme = 2-polycyclic polycyclic organomethylmethanol) are reported.
Abstract: The synthesis and characterization of [Cu(CH3CCl2CO2)2(3-mpyc)2] (1) (3-mpyc = methyl-3-pyridylcarbamate) and [Cu(CH3CHBrCO2)2(2-pyme)2] (2) (2-pyme = 2-pyridylmethanol) are reported. The compounds under study were characterized by IR, electronic spectroscopy and X-ray analysis. The molecular structure of both Complexes 1 and 2 is mononuclear. The coordination environment around each copper(II) atom is a distorted tetragonal bipyramid.
TL;DR: In this paper, the Schiff base N-salicylidene-2-hydroxyaniline (shaH2) with M(CO)6 (M=Cr and W) in THF under reduced pressure resulted in the formation of CrO2( CO)2(shaH 2) (1).
Abstract: Interaction of the Schiff base N-salicylidene-2-hydroxyaniline (shaH2) with M(CO)6 (M=Cr and W) in THF under reduced pressure resulted in the formation of CrO2(CO)2(shaH2) (1) and W(CO)2(shaH)2 (4). The two complexes MoO(sha) (2) and Mo2O4(sha)2 (3) were isolated from the reaction of Mo(CO)6 with shaH2 in air, depending on the reaction period. All complexes were characterised by elemental analysis, IR, mass and 1H NMR spectroscopy. The structural studies of the complexes revealed that the ligand shaH2 bonds to the metal through the oxygen atoms of the hydroxyl groups and the nitrogen atom of the imine group. Magnetic studies of 1 showed it to be paramagnetic with μeff = 2.8 BM, suggesting that Cr is in a high-spin (d2) electronic configuration. The other complexes 2–4 showed diamagnetic behaviour. Electronic spectra of the complexes in different donor solvents displayed weak visible bands due to ligand-to-metal charge transfer. The thermal properties of the complexes were investigated by thermogravimetry ...
TL;DR: Two novel compounds, [Cu2(pydc)2]2(inta)2(H2O)2 ]·3H2Os 1 and [Cu 2(Pydc2]5]·2H 2O 2, have been synthesized in aqueous solution and characterized by single-crystal X-ray diffraction, elemental analyses and IR spectra.
Abstract: Two novel compounds, [Cu2(pydc)2(inta)2(H2O)2]·3H2O 1 (pydc = 2,6-pyridinedicarboxylic acid, inta = isonicotinic acid) and [Cu(pydc)2][Cu(H2O)5]·2H2O 2, have been synthesized in aqueous solution and characterized by single-crystal X-ray diffraction, elemental analyses and IR spectra. Compound 1 exhibits reverse saturable absorption and self-defocusing. X-ray structural analysis reveals that Compounds 1 and 2 both possess π–π stacking and hydrogen-bonding interactions forming three-dimensional (3D) networks. Crystal data for 1: a = 7.2345(14), b = 12.219(2), c = 17.069(3) A, α = 90.44(3), β = 91.82(3), γ = 93.56(3)°, Z = 1, R1 = 0.0435, wR2 = 0.1216. Crystal data for 2: a = 8.3708(17), b = 27.386(6), c = 9.6170(19) A, α = 90.00, β = 98.14(3), γ = 90.00°, Z = 3, R1 = 0.0742, wR2 = 0.2160.
TL;DR: The reaction between NiA(ClO4)2 and NaHL2 has led to the formation of a highly unusual trimetallic bis-[triscyanoximato) nickel(II)] anionic complex anion instead of the expected Ni(II) macrocyclic complex with coordinated cyanoxime ligands as mentioned in this paper.
Abstract: The reaction between the NiA(ClO4)2 and NaHL2 {where A = 14ane[N4], the macrocyclic ligands derived from the product of template condensation of 2,6-diacetylpyridine with aliphatic 3,3′-diaminodipropylamine, NH2(CH2)3NH(CH2)3NH2; and L = 2-cyano-2-isonitrosoacetamide anion, ACO− (amidecyanoxime, NC-C(NO)-C(O) )} has led to the formation of a highly unusual trimetallic bis-[ fac-(triscyanoximato) nickel(II)] anionic complex anion instead of the expected Ni(II) macrocyclic complex with coordinated cyanoxime ligands. Two equivalent and symmetric trigonal-prismatic NiL units are connected to form the [NaNi2L6]− anion by the presence of a central sodium cation. The latter is located between two NiL anions and has an octahedral NaO6 geometry comprised of oxygen atoms of the nitroso group of the cyanoxime ligand. The oxime ligand is planar and adopts a cis-anti configuration in the complex.
TL;DR: In this paper, a tetradentate, N2O2-type Schiff base, synthesized from 1,2-bis-(o-aminophenoxy)ethane and 2-hydroxynaphthalin-1-carbaldehyde, forms stable complexes with transition metal ions such as Cu(II, Ni(II), VO(IV) and Zn(II) in DMF.
Abstract: A novel tetradentate, N2O2-type Schiff base, synthesized from 1,2-bis-(o-aminophenoxy)ethane and 2-hydroxynaphthalin-1-carbaldehyde, forms stable complexes with transition metal ions such as Cu(II), Ni(II), VO(IV) and Zn(II) in DMF. Microanalytical data, elemental analyses, magnetic measurements, 1H NMR, UV, visible and IR-spectra as well as conductance measurements were used to confirm the structures.
TL;DR: In this paper, the complex bis(n-o-methylphenyl-N′-ethoxycarbonylthiourea)copper(I) chloride was prepared by reaction of cupric chloride with the corresponding thiourerea derivative, and its structure determined by X-ray diffraction methods.
Abstract: The complex bis(N-o-methylphenyl-N′-ethoxycarbonylthiourea)copper(I) chloride was prepared by reaction of cupric chloride with the corresponding thiourea derivative. The complex was characterized by IR and 1H NMR and its structure determined by X-ray diffraction methods. The complex is monoclinic, space group P21/n with cell dimensions a = 8.014(3), b = 21.018(7), c = 15.891(5) A and β = 101.537(6). Two thiourea ligands and one Cl atom bond to Cu(I) to form a three-coordinate complex with trigonal planar coordination geometry. Intramolecular H-bonds influence the thiourea coordination properties and stabilize the configuration of the complex.
TL;DR: The title complex (C7H6N2)3(C4H5NO4)Co·2H2O) has been prepared and its crystal structure determined by single-crystal X-ray diffraction methods.
Abstract: The title complex, (C7H6N2)3(C4H5NO4)Co·2H2O, has been prepared and its crystal structure determined by single-crystal X-ray diffraction methods. The cobalt atom is octahedrally coordinated by three benzimidazole molecules and an iminodiacetate anion. The anion coordinates facially as a tridentate. Extensive intermolecular hydrogen bonding and C−H· · ·π interactions occur in the crystal. Thermal decomposition of the complex has been studied by thermogravimetry and differential scanning calorimetry. The IR spectral assignments were based on the molecular structure.
TL;DR: In this paper, the photochemical reaction of metal carbonyls with salicylaldehyde methanesulfonylhydrazone (salmsh) was used to synthesize five new complexes, [M(CO)5(salmh)] (M = Cr; Cr; 1, Mo; Mo; 2, W; W;
Abstract: Five new complexes, [M(CO)5(salmsh)] (M = Cr; 1, Mo; 2, W; 3), [Re(CO)4Br(salmsh)], 4, and [Mn(CO)3 (salmsh)], 5, have been synthesized by the photochemical reaction of metal carbonyls with salicylaldehyde methanesulfonylhydrazone (salmsh). The complexes have been characterized by elemental analyses, EI mass spectrometry, FT-IR and 1H NMR spectroscopy. The spectroscopic studies show that salmsh behaves as a monodentate ligand coordinating via the imine N donor atom in 1–4 and as a tridentate ligand in 5.
TL;DR: In this paper, two types of complex structures were characterized for Zn(RaaiR′)4]-ClO42·6H2O with 1-alkyl-2-(arylazo)imidazoles.
Abstract: Zn(ClO4)2·6H2O reacts with 1-alkyl-2-(arylazo)imidazoles [RaaiR′, where R = H (a), Me (b); R′ = Me (1), Et (2)] affording orange–yellow [Zn(RaaiR′)4](ClO4)2 (3,4) complexes. When excess sodium azide is added to the reaction, orange–red, dimeric azido-complexes of the type [Zn(RaaiR′)(N3)(μ-1,1-N3)]2 (5,6) are obtained. Both types of complex were characterized. Structures were confirmed by single-crystal X-ray diffraction studies of [Zn(HaaiEt)4](ClO4)2 (3b) and [Zn(HaaiMe)(N3)(μ-1,1-N3)]2 (5a).
TL;DR: A series of cobalt(II) and copper (II) complexes of (2-acetylpyridine)-(5,6-diphenyl-[1,2,4]triazin-3-yl) hydrazone, APyTHy, L, having the formulae [LMCl2]·nH 2O, [L2Cu(H2O)2](ClO4)2)2 and [L 2M]X2·n H2O (X = OAc or ClO4
Abstract: A series of cobalt(II) and copper(II) complexes of (2-acetylpyridine)-(5,6-diphenyl-[1,2,4]triazin-3-yl) hydrazone, APyTHy, L, having the formulae [LMCl2]·nH2O, [L2Cu(H2O)2](ClO4)2 and [L2M]X2·nH2O (X = ClO4 or OAc; M = Co or Cu and n = 0, 2 or 4) were isolated and characterized by elemental analysis, molar conductance, magnetic moment and IR, electronic and ESR spectral measurements. The IR spectra indicate that APyTHy behaves as a neutral tridentate ligand, coordinating via a triazine-N, azomethine-N and pyridine-N, except for [LCuCl2] and [L2Cu]X2·nH2O (X = OAc or ClO4), where it acts as a bidentate, not using the triazine-N in complexation. The magnetic moment and electronic spectral data suggest a distorted octahedral structure for 1 : 2 Co(II) complexes, a tetrahedral geometry for 1 : 2 Cu(II) complexes and a trigonal bipyramidal structure for [LCu(H2O)2](ClO4)2 and [LMCl2]·nH2O (M = CoII or CuII; n = 0 or 2) complexes. Upon heating the green [LCuCl2]·2H2O, brown square planar [LCuCl2] was produced....
TL;DR: In this paper, the distortion of the coordination polyhedron, the arrangement of the donor atoms and the packing structure of 2,6-bis(hydroxymethyl)pyridine (dhmp) complexes were investigated in terms of the different kinds of anions and cations.
Abstract: 2 : 1 (L : M) Complexes of 2,6-bis(hydroxymethyl)pyridine (dhmp) with different Co(II) salts [CoCl2·6H2O, Co(SCN)2, Co(NO3)2·6H2O, CoSO4·7H2O and Co(OTos)2·6H2O] and Ni(II) salts [NiCl2·6H2O, Ni(NO3)2·6H2O, NiSO4·7H2O and Ni(OTos)2·6H2O] have been prepared (1–9) and studied by infrared spectroscopy and X-ray crystallography. Influences on the distortion of the coordination polyhedron, the arrangement of the donor atoms and the packing structure of the complexes were investigated in terms of the different kinds of anions and cations. In the metal chloride Complexes 1 and 2, water of hydration was found, while in Complex 3 the counterion (SCN–) acts as a ligand. The crystal structures of all complexes, except 3, show N2O4 hexacoordinated metal ions; in 3 the coordination environment is N4O2. Complex 1 is another exception in containing cobalt(III) instead of cobalt(II) as for the other complexes with cobalt salts. Logically, in Complex 1, one of the dhmp ligands is mono-deprotonated. In the neutral Complexe...
TL;DR: In this paper, the protonated imidazole diphosphopentamolybdenum polyoxometalate (C4H7N2)4[HP2Mo5O23]·H3O· 4.5H2O has been synthesized and its structure has been determined by single-crystal X-ray diffraction.
Abstract: The protonated imidazole diphosphopentamolybdenum polyoxometalate (C4H7N2)4[HP2Mo5O23]·H3O· 4.5H2O has been synthesized and its structure has been determined by single-crystal X-ray diffraction. This compound crystallizes in the triclinic crystal system, space group P(−1), a = 10.171(2), b = 11.839(2), c = 20.170(4) A, α = 75.69(3), β = 84.56(3), γ = 64.90(3)°, V = 2130.8(7) A3, Z = 2 and R = 0.0329. The compound is composed of [HP2Mo5O23]5− clusters and and H3O+ cations as well as water of crystallization, and forms a supramolecular network structure through hydrogen bonds. The monoprotonated polyanions are held together by two strong hydrogen bonds [d O…O = 2.582(7) and 2.581(8) A]. Density functional theory (DFT) calculation has been carried out to investigate the electronic properties of the [H n P2Mo5O23](6− n )− (n = 0, 1, 2) polyanions. Mulliken charges for all atoms have been analyzed. The results show that the negative charges delocalize over all types of oxygen atoms, and molybdenum and phosphor...
TL;DR: In this article, a novel copper complex, [Cu(dipic)(H2O)2] n (H2Dipic = 2,6 pyridinedicarboxylic acid), was synthesized and its crystal structure determined by X-ray diffraction, which has a polymeric structure of infinite 1D zigzag chains, consisting of six-coordinate Cu(II) units.
Abstract: A novel copper complex, [Cu(dipic)(H2O)2] n (H2dipic = 2,6-pyridinedicarboxylic acid), was synthesized and its crystal structure determined by X-ray diffraction. The complex has a polymeric structure of infinite one-dimensional (1D) zigzag chains, consisting of six-coordinate Cu(II) units. Each copper(II) ion is in a distorted octahedral environment with a CuNO5 core: two oxygen atoms and one nitrogen atom from one dipic anion, one oxygen atom from an adjacent dipic ligand and two oxygen atoms from coordinated water. Each dipic anion connects two copper ions via a μ2-oxygen atom. The zigzag 1D-chains are linked by extensive hydrogen bonds to form 2D infinite sheets.
TL;DR: Schiff-base complexes of ruthenium (1-5) have been synthesized using Schiff-base ligands derived by condensation of either 1,2-phenylenediamine with aldehydes (salicyldehyde, 2-pyridinecarboxaldehyde) or acetylacetone with amines (2-aminophenol, 2aminomethyl pyridine). All complexes were characterized by analytical, spectroscopic, conductance, magnetic moment and electrochemical studies as discussed by the authors.
Abstract: Schiff-base complexes of ruthenium (1–5) have been synthesized using Schiff-base ligands derived by condensation of either 1,2-phenylenediamine with aldehydes (salicyldehyde, 2-pyridinecarboxaldehyde) or acetylacetone with amines (2-aminophenol, 2-aminomethylpyridine). All complexes were characterized by analytical, spectroscopic, conductance, magnetic moment and electrochemical studies. At room temperature, complexes 1–5 catalyze the oxidation of both saturated and unsaturated hydrocarbons using tert-butylhydroperoxide (t-BuOOH). A mechanism involving formation of and transfer from a reactive high valency Ru(V)-oxo species as the catalytic intermediate is proposed for the processes.
Abstract: Two novel zinc complexes [Zn2(bte)2(phth)2](H2O)4 (1) and [Zn(bte)(terph)](H2O)2 (2) (phth = 1,2-benzenedicarboxyl, terph = 1,4-benzenedicarboxyl, bte = bis(1,2,4-triazole-1-yl)ethane) were synthesized and characterized and their crystal structures were determined by X-ray diffraction analysis. Complex 1 crystallizes in the orthorhombic space group Pna21, with a = 11.0742(10), b = 14.4132(13), c = 22.4188(18) A, V = 3578.4(5) A3, Z = 4; R 1 = 0.0495, wR 2 = 0.1026. Complex 2 crystallizes in the triclinic space group 1, with a = 9.468(6), b = 9.682(5), c = 10.410(6) A, α = 101.533(8), β = 104.783(9), γ = 92.042(5)°, V = 900.3(9) A3, Z = 2; R 1 = 0.0520, wR 2 = 0.1193. A two-dimensional (2D) network in 1 is formed through helical chains linking Zn2(phth)2 14-membered rings forming 50-membered macrometallacyclic rings. The 2D rhombic network in 2 is formed through bridging terph ligands linking Zn2(bte)2 18-membered rings.
TL;DR: In this paper, the interaction of metal carbonyls with the tetradentate Schiff base bis(salicylaldehyde)phenylenediimine (salphenH2) was studied in THF.
Abstract: Interaction of metal carbonyls M(CO)6 (M = Cr, Mo and W) with the tetradentate Schiff base bis(salicylaldehyde)phenylenediimine (salphenH2) was studied in THF. Under reduced pressure, reaction of salphenH2 with M(CO)6 (M = Cr, Mo) yielded Cr(CO)2(salphen) 1 and MoO(CO)(salphen) 2. The complexes MoO2(salphenH)2 3 and W2O6(salphenH2) 4 were isolated from reactions in air. All the complexes were characterized by elemental analysis, mass spectrometry and IR and 1H NMR spectroscopy. Spectroscopic studies of the reported complexes revealed the proposed structures. The UV-vis spectra of the complexes in different solvents showed bands due to either metal-to-ligand or ligand-to-metal charge transfer. Thermal properties of the chromium and molybdenum complexes were investigated by thermogravimetric techniques.
TL;DR: In this article, the title compound of the triclinic space group with a π-π stacking interaction involving thiazole rings occurs between adjacent supramolecular chains.
Abstract: The title compound crystallizes in the triclinic space group with a = 7.194(3), b = 9.790(5), c = 12.492(1) A, α = 82.407(16), β = 86.664(15), γ = 89.882(15)°. The Mn(II) complex assumes distorted octahedral coordination geometry, formed by diaminobithiazole (DABT), an oxydiacetate dianion (ODA) and a water molecule. The tridentate ODA ion chelates to the Mn(II) atom in a meridional configuration. Each carboxyl group coordinates to the Mn(II) atom as a monodentate. Uncoordinated carboxyl oxygen atoms are involved in a hydrogen-bonding network. DABT chelates to the Mn(II) atom with a coplanar configuration. Coordinated water is hydrogen bonded to carboxyl groups of ODA of a neighboring complex to form supramolecular chains. A π–π stacking interaction involving thiazole rings occurs between adjacent supramolecular chains. A difference of 180 cm−1 between asymmetric and symmetric stretching vibrations of the carboxyl group corresponds to the extensive hydrogen-bonding network involving the carboxyl group.