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1
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Intermolecular interactions in 2,4-dinitrophenylhydrazine hydrochloride hydrate: X-ray structural and quantum mechanical study

100%
Kruszynski R.
Open Chemistry
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2008
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vol. 6
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issue 4
542-548
EN
2,4-dinitrophenylhydrazine hydrochloride hydrate (I) was determined by X-ray crystallography, and the intermolecular interaction energies were calculated in terms of Natural Bond Orbital analysis. The asymmetric unit of (I) consists of a dinitrophenylhydrazinium cation, a chloride anion and a water molecule. The interatomic distances and angles in (I) show no unusual values. In the structure there are intermolecular N-H⊎⊎⊎O, N-H⊎⊎⊎Cl, O-H⊎⊎⊎Cl, C-H⊎⊎⊎O hydrogen bonds with bonding energy ranging form 16.03 to 0.76 kcal mol−1. These hydrogen bonds create the following N1 motifs: 6D, S(5), S(6), C(6), C(9). N1D motifs become infinite at the third level and are 2C 32(6), C 32(7). [...]
2
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Synthesis, crystal structure, spectroscopic and thermal investigations of neodymium(III) biphenyl-4,4′-dicarboxylate framework

100%
Łyszczek R., Mazur L.
Open Chemistry
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2012
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vol. 10
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issue 4
1165-1174
EN
The three-dimensional complex {[Nd(bpdc)1.5(DMF)]·1.4DMF}n (DMF=N,N′-dimethylformamide, bpdc=biphenyl-4,4′-dicarboxylate) was synthesized using the solvothermal method. The crystal structure of the neodymium(III) complex has been determined by single-crystal X-ray diffraction method at 100(2) K. The polymeric structure consists of neodymium polyhedra bridged by bpdc ligands. Eight-coordinated Nd(III) atoms are surrounded by seven oxygen atoms from six bpdc moieties and one oxygen atom from the DMF molecule. The 3D structure of the complex contains two types of channels occupied by DMF molecules. Thermal analysis revealed that DMF molecules are lost in a stepwise manner. The infrared spectrum confirmed full deprotonation of acid and presence of DMF molecules in the structure. [...]
3
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Methyl- and methoxysalicylatocopper complexes with 2-pyridylmethanol: Synthesis, spectral properties, structure and EPR characterization in solid-state and in solution

100%
Repická Z., Puchoňová M., Husáriková L., Monco J., Koman M., Mazúr M., Valigura D.
Open Chemistry
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2012
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vol. 10
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issue 5
1506-1515
EN
The syntheses and characterizations of salicylatocopper(II) complexes of the formula Cu(X-sal)2(2-pyme)2 (X = 3-MeO (1), 4-MeO (2), 3-Me (3), 4-Me (4) and 5-Me (5), where 3-MeOsal− = 3-methoxysalicylate, 4-MeOsal− = 4-methoxysalicylate, 3-Mesal− = 3-methylsalicylate, 4-Mesal− = 4-methylsalicylate, 5-Mesal− = 5-methylsalicylate anion, and 2-pyme = 2-pyridylmethanol) are reported. The composition was determined by elemental analysis, and ligand coordination modes have been determined by spectroscopic methods (IR, UV-VIS). The crystal structure determination of [Cu(3-MeOsal)2(2-pyme)2] (1) and [Cu(5-Mesal)2(2-pyme)2] (5) have confirmed conclusions originally based on spectral data. EPR measurements of frozen water/methanol solutions containing different copper(II): 2-pyme molar ratios have indicated presence of complexes with only two nitrogen donor atoms bonded to each central atom. [...]
4
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Structure, conformation and hydrogen bonding of two amino-cycloalkanespiro-5-hydantoins

100%
Todorov P., Petrova R., Naydenova E., Shivachev B.
Open Chemistry
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2009
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vol. 7
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issue 1
14-19
EN
The crystal structures of 3-amino-cycloheptanespiro-4′-imidazolidine-2′,5′-dione (I) {systematic name: 3-amino-1,3-diazaspiro[4.6] undecane-2,4-dione} and 3-amino-cyclooctanespiro-4′-imidazolidine-2′,5′-dione (II) {systematic name: 3-amino-1,3-diazaspiro[4.7] dodecane-2,4-dione}, have been determined. In both compounds the polar hydantoin groups cause molecules to aggregate via N-H...O and N-H...N interactions, forming a layer structure, in which the cycloalkane rings project outwards from the central, more polar, region. The observed molecular structure is compared with that calculated by density functional theory methods. [...]
5
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The crystal structure of Ho4Ni11In20

100%
Tyvanchuk Y., Svitlyk V., Kalychak Y.
Open Chemistry
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2012
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vol. 10
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issue 2
354-359
EN
The polycrystalline Ho4Ni11In20 was obtained by arc-melting of the elements. The subsequent high temperature procedure was used for single crystal growth. Crystal structure of the compound was investigated by X-ray single crystal method: U4Ni11Ga20 type, C 2/m, a = 22.4528(17), b = 4.2947(3), c = 16.5587(13) Å, β = 124.591(5)°, R1 = 0.0276, wR2 = 0.0493 for 1989 independent reflections with [I>2σ(I)]. The structure is composed of three-dimensional network from Ni and In atoms in which Ho atoms fill distorted pentagonal channels. [...]
6
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Synthesis and crystal structure of 1-ethyl-3-(phenyl)-1,2,3-triazolium percholorate

100%
Doreswamy B., Mahendra M., Anandalwar S., Prasad J., Mantelingu K., Basappa, Rangappa K.
Open Chemistry
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2003
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vol. 1
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issue 4
477-490
EN
The isolation of stable carbenes of the Arduengo (1a) and Wanzlick (2a) type has prompted us to look for stable nitrenium ions of the related structural type 1-ethyl-3-(phenyl)-1,2,3-triazolium perchlorate (6+). The title compound C10H14Cl N3O4 was isolated and structure was investigated by X-ray crystallography. It crystallizes in the monoclinic space group P21/c with cell parameters a=6.697(4) Å, b=9.724(9) Å, c=19.844(2) Å and Z=4. The final residual factor is R1=0.0471 for 1545 reflections with I>2σ(I). The structure exhibits intermolecular hydrogen bonds.
7
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A novel redox-active calix[4]arene-tetrathiafulvalene dyad

100%
Zhao B.-T., Zhu X.-M., Peng Q.-M., Yan Z.-N., Derf F., Sallé M.
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EN
A novel redox-active calix[4]arene-TTF 5 was prepared by the reaction of p-tert-butylcalix[4]arene 4 with the tosylated TTF 3 in the presence of cesium fluoride. The structure of the dyad 5 was identified by X-ray diffraction analysis, and the preliminary electrochemical properties of 5 were investigated by cyclic voltammetry (CV), for which two reversible one-electron waves were observed. Moreover, the UV-vis absorption spectra studies show that the dyad 5 undergoes progressive oxidation at the TTF moiety in presence of increasing amounts of Cu2+ or Hg2+. [...]
8
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Physicochemical characteristics of 2-, 3- and 4-methylpyridinium tetrachloroferrates(III)

100%
Wyrzykowski D., Wera M., Sikorski A., Jacewicz D., Chmurzyński L.
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EN
The crystal structure of 2-methylpyridinium tetrachloroferrate(III) was determined. The iron cation is tetracoordinated by chloride anions, and it adopts a slightly distorted tetrahedral coordination with three angles smaller, two almost equal and one larger than the tetrahedral. The compound is isostructural with its 3-, and 4-methylpyridinium analogues. The thermal properties of 2-, 3- and 4-methylpyridinium tetrachloroferrates(III) have been studied using TG and DSC techniques. The compounds exhibit a high stability in the melt. [...]
9
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The crystal structure of Sm4Ni11In20 and its relation to other indium-rich compounds

100%
Tyvanchuk Y., Svitlyk V., Pustovoychenko M., Kalychak Y.
Open Chemistry
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2014
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vol. 12
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issue 2
227-232
EN
Polycrystalline Sm4Ni11In20 was obtained by arc-melting of metal ingots. A subsequent high temperature treatment was used for single crystal growth. The Sm4Ni11In20 crystal structure (U4Ni11Ga20 type; C2/m, a = 22.5457(3) Å, b = 4.34929(5) Å, c = 16.5479(2) Å, β = 124.592(2)°, R1 = 0.0358, wR2 = 0.0934) was determined by single crystal synchrotron radiation X-ray diffraction from 2014 independent reflections with I > 2σ(I). Sm4Ni11In20 extends the R 4Ni11In20 (R = Y, Gd, Tb, Dy, Ho) series of phases. The R 4Ni11In20 and RNi3In6 (LaNi3In6 type; R = La, Ce, Pr, Nd, Eu) series have similar compositions. Their structures share similar fragments; in particular the rare earth atom coordination polyhedra are pentagonal prisms with additional atoms.
10
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A dimeric copper coumarin complex: synthesis and crystal structure of [{Cu(4-methyl-7-(salicylideneamino)coumarin)2}2]

88%
Aazam E., EL Husseiny A., Hitchcock P., Alshehri J.
Open Chemistry
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2008
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vol. 6
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issue 2
319-323
EN
A binuclear copper complex [{Cu(L)2}2], C68H48Cu2N4O12C (where L is 4-methyl-7-(salicylideneamino)coumarin), has been synthesized and characterized using elemental analysis, molar conductance measurements, and infrared, ultraviolet and ESR spectrosopy. The molecular structure of title compound, determined by single-crystal X-ray diffraction studies, reveals that the two symmetric Cu(L)2 units are associated into a dimer by rather long Cu...O bonds. The Cu(II) ions are bridged via the phenolic oxygen of one of the monomers and have distorted trigonal bipyramidal conformation geometry. Within each monomer the two methylsubstituted coumarin skeletons are trans to one another, but adopt a parallel arrangement with respect to the other monomer. Only half of the complex molecule can be found in the asymmetric unit, Z′ = 0.5, the other half is generated by the symmetry centre. [...]
11
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New 5-bromo-2-hydroxybenzaldehyde S-ethylisothiosemicarbazone and its mixed-ligand Cu(II) complex with imidazole: synthesis, characterization and DFT calculation

88%
Takjoo R., Akbari A., Ahmadi M., Rudbari H., Bruno G.
Open Chemistry
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2013
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vol. 11
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issue 11
1844-1851
EN
A new Schiff base ligand of 5-bromo-2-hydroxybenzaldehyde S-ethyl-isothiosemicarbazone (H2L) was synthesized and its mixed-ligand Cu(II) complex was also prepared by reaction of Cu(NO3)2·3H2O with H2L and imidazole. Their structures were fully characterized by elemental analysis, FT-IR, molar conductivity and UV-Vis methods. The analytical data suggest that the metal, H2L and imidazole ratios in the Schiff base complex are 1:1:1. Single crystal diffraction was also used to better understand the molecular structure of the Cu(II) complex. The results of physico-chemical analyses of the Schiff base complex reveal the coordination geometry around the central atom is square planar. The H2L ligand (NNO donor) is coordinated to the metal center as a tridentate bionegatively agent. Another position of the square planar geometry is occupied by the imidazole ligand. Furthermore, computational studies of the new complex were performed by carrying out DFT calculations. Geometry optimization and natural band analysis of the complex is discussed in further detail. [...]
12
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Unusual potassium-oxalate coordination in the two-dimensional trimetallic [CoCl(NH3)5][KCr(C2O4)3]·0.5H2O complex

88%
Wrzeszcz G., Wojtczak A., Zawadzka M.
Open Chemistry
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2014
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vol. 12
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issue 6
652-658
EN
A new heterometallic compound, [CoCl(NH3)5][KCr(C2O4)3]·0.5H2O (1), has been synthesized and characterized by elemental analysis, IR and electronic spectra, thermal analysis, variable temperature magnetic susceptibility measurements, and single crystal X-ray diffraction. Compound 1 consists of two-dimensional [{KCr(C2O4)3}n]2n− layers, [CoCl(NH3)5]2+ ions and water molecules. Within the 2-D layer, three different types of oxalate coordination modes are present. Each K cation is coordinated by eight oxygen atoms from oxalate groups and also weakly interacts with the ninth oxygen atom. The extensive network of hydrogen bond is formed between the [KCr(C2O4)3]2− layer and the [CoCl(NH3)5]2+ ions. These interactions involve all hydrogen atoms of ammonia ligads and water molecule.
13
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Role of temperature in the numerical analysis of CaO under high pressure

88%
Bhardwaj P., Singh S.
Open Chemistry
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2010
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vol. 8
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issue 1
126-133
EN
In this paper we focus on the elastic and thermodynamic properties of the B1 phase of CaO by using the modified TBP model, including the role of temperature. We have successfully obtained the phase transition pressure and volume change at different temperatures. In addition elastic constants and bulk modulus of B1 phase of CaO at different temperatures are discussed. Our results are comparable with the previous ones at high temperatures and pressures. The thermodynamical properties of the B1 phase of CaO are also predicted. [...]
14
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Synthesis, structures, and spectroscopic properties of copper(I) complexes bearing 7-acetamido-4-methyl-1,8-naphthyridin-2-carbaldehyde azine and 1,2-bis(diphenylphosphino)ethane ligands

88%
Chi S.-M., Wang Y.-F., Gan X., Wang D.-H., Fu W.-F.
Open Chemistry
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2009
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vol. 7
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issue 4
923-928
EN
A new ligand napaa (napaa = 7-acetamido-4-methyl-1,8-naphthyridin-2-carbaldehyde azine) and its two dinuclear copper(I) complexes, Cu2(napaa)(dppe)2(ClO4)2 (1) and Cu2(napaa)(PPh3)4(BF4)2 (2) (dppe = 1,2-bis(diphenylphosphino)ethane) and PPh3 = triphenylphosphine) were synthesized and characterized, and the structure of 1 was determined by X-ray crystal analysis. Each copper atom in 1 has a distorted tetrahedral geometry in which the metal center is associated to napaa and dppe ligands displaying chelating coordination modes and the naphthyridine rings of napaa are almost coplanar. The two complexes exhibit similar electronic absorption spectra with λmax at about 366 nm, which can be tentatively assigned to metal-to-ligand charge-transfer (MLCT) transition. The assignment was further supported by density functional theory (DFT) calculations. [...]
15
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Applicability of Gd-doped BaZrO3, SrZrO3, BaCeO3 and SrCeO3 proton conducting perovskites as electrolytes for solid oxide fuel cells

88%
Zając W., Rusinek D., Zheng K., Molenda J.
Open Chemistry
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2013
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vol. 11
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issue 4
471-484
EN
Four proton conducting oxides of perovskite structure: BaZrO3, SrZrO3, BaCeO3 and SrCeO3 doped with 5 mol.% of gadolinium are compared in terms of crystal structure, microstructure, sinterability, water sorption ability, ionic transference number, electrical conductivity and stability towards CO2. Relations between proton conductivity, structural and chemical parameters: pseudo-cubic unit cell volume, lattice free volume, tolerance factor, crystal symmetry and electronegativity are discussed. The grain boundary resistance is shown to be the limiting factor of total proton-conductivity for the materials examined. The highest proton conductivity was observed for BaCeO3, however, it turned out to be prone to degradation in CO2-containing atmosphere and reduction at high temperatures. On the other hand, Ba and Sr zirconates are found to be more chemically stable, but exhibit low electrical conductivity. Electrical conductivity relaxation upon hydration is used to calculate proton diffusion coefficient. Selected materials were tested as electrolytes in solid oxide fuel cells. [...]
16
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Octahedral CuII and NiII complexes manifesting with N′-[1-(pyridin-2-yl)ethylidene] acetohydrazide: Structural outlooks and spectral characteristics

88%
Datta A., Huang J.-H., Clegg J., Liu P.-H., Chuang S.-J.
Open Chemistry
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2013
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vol. 11
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issue 1
116-122
EN
A tridentate hydrazone precursor, N′-[1-(pyridin-2-yl)ethylidene]acetohydrazide (L) (1:1 refluxed product of acetichydrazide and 2-acetylpyridine), produced two octahedral CuII and NiII derivatives, [CuL2]·NO3 (1) and [NiL2]·ClO4·H2O (2). Both are subjected to X-ray diffraction system, and structural investigation shows that the central metal atom (CuII or NiII) adopts a distorted octahedral geometry with N4O2 donor sets by coordination of a pair of independent hydrazone precursors. Besides X-ray study, IR and UV-vis spectra, thermal analysis and room temperature magnetic moments are utilized for establishing significant characteristics of both complexes. It is apparent that the M-Npyridine bonds are slightly longer than the M-Nimino bonds, Cu1-N1 and Cu1-N4 [2.300(2) and 2.038(2) Å] for 1 and Ni1-N1 and Ni1-N4 [2.075(2) and 2.084(1) Å] for 2, Cu1-N2 and Cu1-N5 [2.062(1) and 1.932(1) Å] for 1 and Ni1-N2 and Ni1-N5 [2.008(2) and 1.975(2) Å] for 2, respectively. As per our observation, the effective magnetic moment value (µeff) is found to be 1.77 B.M. for 1 and 3.06 BM for 2, respectively.
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The structural, magnetic, hydrogenation and electrode properties of REMg2Cu9−xNix alloys (RE=La, Pr,Tb)

88%
Pavlyuk V., Rozycka-Sokolowska E., Marciniak B., Paul-Boncour V., Dorogova M.
Open Chemistry
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2011
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vol. 9
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issue 6
1133-1142
EN
The LaMg2Cu9, PrMg2Cu9, LaMg2Cu4Ni5, PrMg2Cu4Ni5 and TbMg2Cu6Ni3 alloys were prepared for the investigations of crystal structure, magnetic and hydrogen storage properties. The magnetic properties of several REMg2Cu9−xNix compounds have been studied up to 9 T and from 2 to 300 K. Tb compounds show a ferrimagnetic (with Ni) or antiferromagnetic (without Ni) behaviour, which can be attributed to the Tb magnetic structure. At high temperature a paramagnetic Curie Weiss behaviour is observed and the effective moment corresponds to that of Tb. A magnetic contribution of Pr moment is observed in both Pr compounds, with larger magnetization for PrMg2Cu4Ni5 and a transition at 3 K. The hydrogen absorption occurs at 95 bar for LaMg2Cu9 (3 H f.u.−1) and above 2 bars for LaMg2Cu4Ni5 (1.6 H f.u.−1). The effect of Cu-Ni substitution on the electrochemical properties of LaMg2M9 ternary alloys was investigated leading to maximum discharge capacity of 250–310 mAh g−1. [...]
18
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Self-assembled hydrogen-bonded coordination networks in two copper(II) carboxylates with 4-pyridylmethanol

88%
Maroszová J., Moncol J., Padělková Z., Sillanpää R., Lis T., Koman M.
Open Chemistry
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2011
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vol. 9
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issue 3
453-459
EN
The crystal and molecular structure of [Cu(nif)2(4-PM)2]·CH3OH (1) and [Cu(2-Clbz)2(4-PM)2(H2O)] (2), (where nif = niflumate anion, 2-Clbz = 2-chlorobenzoate anion and 4-PM is the 4-pyridylmethanol), have been determinated by X-ray crystallography. The Cu2+ cation in (1), is coordinated by two pairs of oxygen atoms from asymmetric bidentate niflumate anions and by a pair of pyridine nitrogen atoms from monodentate 4-pyridylmethanol ligands in trans position forming an extremely elongated bipyramid. The Cu2+ cation in (2), is coordinated by a pair of oxygen atoms from monodentate 2-chlorobenzoate anions, further by a pair of pyridine nitrogen atoms from monodentate 4-pyridylmethanol ligands and finally by a water oxygen atom forming a tetragonal-pyramidal coordination polyhedron. The molecules of both complexes in crystal structures are linked by O-H…O hydrogen bonds, which created a three-dimensional hydrogen-bonding networks. The Π-Π stacking interactions are also observed in crystal structures of complex 2. The spectral properties (IR and electronic spectra) of both complexes were also investigated.
19
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A new zinc complex of 1-propyl-1H-benzo[d] imidazole: synthesis, characterization and electrocatalysis

88%
Zhuang R., Jian F., Wang K.
Open Chemistry
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2010
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vol. 8
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issue 3
646-651
EN
The present work reports the synthesis, characterization and performance of a new zinc(II) complex of [Zn(C3H7-bim)2Br2] (bim = benzimidazole) as electrocatalyst for trichloroacetic acid and bromate reduction. Its structure was characterized by X-ray crystallography, IR spectroscopy and elemental analysis. The zinc atom adopts a distorted tetrahedral geometry by coordinating to two bromine atoms and two nitrogen atoms from two 1-propyl-1H-benzo[d]imidazole ligands. The electrochemical behavior and electrocatalysis of the zinc complex bulk-modified carbon paste electrode (Zn-CPE) have been studied by cyclic voltammetry. The Zn-CPE shows good electrocatalytic activities toward the reduction of trichloroacetic acid and bromate. The detection limit and the sensitivity are 0.05 μM, 67.43 μA μM−1 for trichloroacetic acid detection, and 0.02 μM, 69.94 μA μM−1 for bromate detection, respectively. This modified electrode shows good reproducibility, high stability, low detection limit, technical simplicity and possibility of rapid preparation, which is important for practical applications. [...]
20
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Synthesis, characterization and crystal structure analysis of a novel oxo-centered mixed-metal complex containing unsaturated bridging carboxylates

88%
Yazdanbakhsh M., Lotfian N., Tavakkoli H., Boese R.
Open Chemistry
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2011
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vol. 9
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issue 4
585-589
EN
A novel oxo-centered trinuclear mixed-metal carboxylate complex with unsaturated bridging ligands [Fe2Cr(µ3-O)(C3H3O2)6(H2O)3]·NO3·4H2O has been synthesized and characterized by means of Elemental analyses, Infrared spectroscopy and Crystal structure analysis. The compound crystallizes isotypically in the monoclinic space group type P21/c. In the compound, each M(III) cation is coordinated by six O atoms from four unsaturated carboxylate groups as bridging ligands, one water molecule as the terminal ligand, and a µ3-oxygen atom in the center of an equilateral triangle. The infrared spectra show resolved bands arising from νasym(COO) and νsym(COO) vibration of bridging carboxylate ligands along with those of νasym(M2M′O) vibration in the complex. The difference between symmetrical and asymmetrical (COO) ligands indicate that the acrylate bridge is present in the structure of complex. [...]
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