- Synthesis, thermal study and some properties of Zn(II), Cd(II) and Pb(II) compounds with mono-, di- and trichloroacetates
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New complexes with formulae: Zn(CClH2COO)2·2H2O, Zn(CCl2HCOO)2·2H2O, Zn(CCl3COO)2·2H2O, Cd(CCl2HCOO)2·H2O, Cd(CCl3/su
- Czylkowska,Raducka,Mierczyński
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- Crystal Structures of Cadmium Phosphidechlorides Cd7P4Cl6and Cd4P2Cl3
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The crystal structure of Cd7P4Cl6(I) has been redetermined and of Cd4P2Cl3(II) solved based on the single crystal X ray diffraction experiments. Crystal data: I, cubic space groupPa3,a=11.936(1) A,z=4, andR=0.0226 for 398 independent reflections and 28 refined parameters; II, cubic space groupPa3,a=12.135(1) A,z=8, andR=0.0256 for 466 independent reflections and 29 refined parameters. Both phases crystallize in a space groupPa3, but have quite different crystal structures. The structure of I comprises a three-dimensional cationic net ∞3[Cd3P2]2+and discrete octahedral anions (CdCl6)4-. The structure of II is based on a fcc packing of cadmium atoms with octahedral and tetrahedral interstices filled with either chlorine or phosphorus atoms or P-P pairs.
- Shevelkov, Andrei V.,Reshetova, Ludmila N.,Popovkin, Boris A.
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- The Tetrachloridoaurates(III) of Zinc(II) and Cadmium(II)
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The first salt-like compounds of dications with [AuCl4]– anions are reported. The compounds Zn[AuCl4]2·(AuCl3)1.115 (1) and Cd[AuCl4]2 (2) are obtained from reactions of MCl2 (M = Zn, Cd) and elemental gold in liquid chlorine at ambient temperature under autogenous pressure and subsequent annealing at 230 °C. The structure of 1 represents an incommensurately modulated composite [superspace group C2/c(α0γ)0s] built of two subsystems. The first subsystem contains chains of zinc(II) tetrachloridoaurate(III), which feature a slightly distorted octahedral coordination of Zn and can be described by the Niggli formula 1∞{Zn[AuCl4]1/1[AuCl4]2/2}. The second subsystem consists of Au2Cl6 molecules, which are located in channels built up by the first subsystem. The structural parameters of the hosted Au2Cl6 molecules show only small deviations from neat AuCl3. The crystal structure of Cd[AuCl4]2 (2) consists of chains built of Cd2+ ions coordinated by bridging [AuCl4]– anions and alternating Cd-Au sequence. Cd has a distorted octahedral coordination environment.
- Landvogt, Christian,Beck, Johannes
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- REFLECTION SPECTRA OF CdCl2-CdBr2 MIXED CRYSTALS IN THE REGION OF BAND GAP EXCITONS.
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The low lying exciton spectra were measured on CdCl//2-CdBr//2 mixed crystals using the cleaved surfaces. The purpose is to investigate how the crystal field contributes to the exciton transitions in the mixed system and to obtain some information about t
- Kondo,Matsumoto
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- Oxidation of cadmium with dicarbonylcyclopentadienyliron chloride in dimethylformamide
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The kinetic and activation parameters of oxidation of cadmium with dicarbonylcyclopentadienyliron chloride in dimethylformamide were determined. The apparent equilibrium constants, enthalpy, and entropy of adsorption of the reactants on the metal surface
- Usanov,Maslennikov,Spirina,Maslennikov
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- Thermal studies N-(2-aminoethyl)-1,3-propanediamine and N-(3-aminopropyl)-1,3-propanediamine complexes of cadmium(II)
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[Cd(aepn)2]X2 · nH2O (where aepn is N-(2-aminoethyl)-1,3-propanediamine, and n = 1 when X is Cl- and Br-, n = 0 when X is 0.5SO2-4, 0.5SeO2-4, NO-/sup
- Mondal, Arunendu,Pariya, Chandi,Ghosh, Ashutosh,Chaudhuri, Nirmalendu Ray
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- Metal exchange between cadmium complexes with natural porphyrins and cobalt chloride in ethanol
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Metal exchange reactions between Cd chlorophyll (a) or Cd pheophorbide (a) and cobalt chloride in ethanol were studied by spectrophotometry. The order of the reaction was determined. It was found that the metal exchange follows the stoichiometric mechanis
- Zvezdina,Berezin,Berezin
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- One-dimensional Cd metal string complex: Synthesis, structural and thermal properties of [(HPy)3(Cd3Cl9)] ∞
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The cadmium metal string complex of [(HPy)3(Cd 3Cl9)]∞ (Py = pyridine) was prepared. Its structural and thermal properties were also investigated. Its existing form in gas phase has been elucidated by density functional calculations. The crystal structure consists of protonation pyridine cations and infinite one-dimensional chains of [Cd3Cl9]3- anions. Each Cd atom is octahedrally surround by bridged chlorine atoms, giving rise to polymeric chain along the a-axis. The pyridinium lie in the middle of the chain to balance the charge. The DFT study indicates that the HOMO orbital of optimized structure is mainly localized on the middle six chloride ions and the LUMO is delocalized. Differential thermal gravimetric analysis shows there is no presence of any structural phase transitions.
- Jian, Fang Fang,Zhao, Pu Su,Wang, Qing Xiang,Li, Ying
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- [PtCl6] and [Cd(NH3)4][PtCl6] as precursors for intermetallic compounds PtZn and PtCd
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Double complex salts (tetraamminezinc and tetraamminecadmium hexachloroplatinates) have been synthesized. Their thermal properties have been studied, as well as the products of their degradation in hydrogen and helium atmospheres. Optimal thermolysis sche
- Zadesenets,Venediktov,Shubin,Korenev
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- Synthesis, crystal and electronic structure of Cd2PCl 2: Influence of cation on characteristic structural features of pnictide halides of Group 12 metals
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Cadmium phosphide chloride Cd2PCl2 was prepared by the ampule synthesis method at 770 K. Crystals were obtained from the gaseous phase by the chemical transport reaction. The crystal structure of Cd 2PCl2 is built of the P2Cd6 octahedra, which are linked in layers by sharing four equatorial vertices. The layers alternate in a fashion analogous to that observed in the K 2NiF4 structural type and are linked in a three-dimensional framework through the halogen atoms. The characteristic features of the crystal and electronic structures of pnictide halides M 2PCl2 (M = Cd or Hg) were considered based on X-ray diffraction data and results of quantum-chemical calculations.
- Olenev,Oleneva,Shevelkov,Popovkin
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- Tuning the inclusion properties and solid-state reactivity of second sphere adducts using conformationally flexible bidentate ligands
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Second-sphere coordination refers to any intermolecular interaction with the ligands directly bound to the primary coordination sphere of a metal ion. In this article, we have successfully applied the second-sphere coordination approach in the construction of versatile host frameworks that can accommodate various guest molecules. We have used a family of bidentate flexible molecules as second-sphere ligands, and the tetrachlorometalate anion [MCl4]2- (where M = Cu, Co, Cd, Zn, and Hg) as the primary coordination sphere to synthesize new second sphere adducts. By introducing an alkyl spacer -(CH2)n- (n = 1, 2, 3, 4) to bibenzylamine (L0), the ligands L1, L2, L3, and L4 with higher degree of flexibility were synthesized. Different guest molecules such as alcohol, acetic acid, acrylic ester, or acetonitrile can be included in the host framework self-assembling diprotonated L1-L4 and [MCl4]2-, leading to a novel type of supramolecular assemblies: CH3CH2OH[L2]2H+·[CuCl4]2- (2), CH3OH[L3]2H+·[MCl4]2- (3), CH3COOH[L3]2H+·[CuCl4]2- (4), CH2CHCOOCH3'[L3]2H+·[MCl4]2- (5-7), CH3CN·H2O'[L4]2H+·[MCl4]2- (8-9), and CH3OH'[L4]2H+·[MCl4]2- (10). L2 forms the quasi-chelating charge-assisted N-H···Cl hydrogen bonds with [MCl4]2- that can transform in the solid-state to a chelated coordination complex following a mechanochemical dehydrochlorination reaction. By increasing the number of methylene groups, ligands L3 and L4 exhibit considerable conformational diversity due to the higher flexibility induced by the backbone chains. The -(CH2)n- spacer lengths of the ligands influences the structural dimensionality, and its solid-state mechanochemical reactivity preventing the transformation from salt [L3-4]2H+·[MCl4]2- to the chelating coordination complex [(MCl2)(L3-4)]. Moreover, the thermal stability of the second sphere adducts has been monitored by thermogravimetric analyses and X-ray powder diffraction (PXRD). We demonstrate that some of the second sphere adducts are dynamic, showing reversible guest release/uptake involving crystalline-to-amorphous-to-crystalline phase transformations. QuantumMechanical (QM) demonstrate that ligands with backbone lengths longer than -(CH2)2- are reticent to react via dehydrochlorination reaction because of the backbone chain length, the symmetry and orientation of the frontier molecular orbitals (FMOs), while for the -(CH2)2-, the length and orientation of the FMOs is optimal for the reaction to occur.
- Guo, Fang,Wang, Xu,Guan, Hong-Yu,Yu, Hai-Bin,Li, Lei,Chen, Shan-Shan,Famulari, Antonino,Martí-Rujas, Javier
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- New halide glasses of the CdX2-PbX2-Kl (X=Cl Br) systems
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The glass forming regions and some properties of the CdBr2-PbBr2-Kl (10 to 50 mol% CdBr2, 10 to 70 mol% PbBr2, 20 to 40 mol% Kl), CdCl2-PbBr2-Kl (10 to 50 mol% CdCl2, 10 to 80 mo
- Petrova, B.,Frumar M.,Stranska, E.,Hlozanek, I.
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- Crystal structure and fluorescence of supramolecular compound [Cd 3Cl6C6N2O8H 22]n
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A novel trinuclear supramolecular compound of [Cd3Cl 6C6N2O8H22]n has been synthesized under alanine with cadmium chloride to the reaction in aqueous solution conditions, and characterized by elemental analyses, FT-IR spectroscopy, X-ray diffraction, DTA-TG. Its crystal structure was determined from single crystal X-ray diffraction. The title compound crystallizes in monoclinic system with space group P21/n. The crystal structure of the compound is characterized by forming a trinuclear 3D supramolecular structure with three cadmium(II) ions, six chloride ions, two molecules D, L-alanine in salt, two coordinated water molecules and two crystal water molecules. Cd(1) is distorted octahedrally coordinated with two oxygen atoms (from the adjacent amino acid and water molecule) and four chloride ions; Cd(2) is smaller extent distorted octahedrally coordinated with two oxygen atoms (from the adjacent amino acids) and four chloride ions. Cd(1) and Cd(2) connected by the bridge bonds of μ2-Cl, μ3-Cl and the carboxyl oxygen into ID chain structure, which further connected by hydrogen bonds to form 3D supramolecular network. Fluorescence test showed that the compound has a good photoluminescence property, respectively. Pleiades Publishing, Ltd., 2011.
- Guo, Ge,Sun, Ruzhong,Dang, Yuanlin
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- Potentiometric Study of Cadmium(II) Halide and Thiocyanate Complexes in Methanol. Determination of Thermodynamic Stability Constants of Third and Fourth Complexation Step
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The stability constants, K3 and K4, of IIXn>2-n (X-=Cl-, Br-, NCS-) complexes in methanol have been determined by X- ion measurements with Ag-
- Soe, Khin Nwe,Doe, Hidekazu,Kitagawa, Toyokichi
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- STUDIES ON TRANSITION-METAL PICOLINE COMPLEXES - I. PREPARATION AND THERMOANALYTICAL INVESTIGATIONS.
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A large number of transition-metal picoline halides were prepared, and their thermal decompositions were investigated by TG, DTG, DTA and thermomicroscopy. The compounds were classified on the basis of their thermal properties and two possible mechanisms of thermal decomposition were established.
- Liptay,Borbely-Kuszmann,Nagy
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- On the chemical vapor transport of ternary transition metal- and earth
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The chemical vapor transport of transition metal tungstates MWO4 (M=Mn, Co, Ni, Cu, Zn, Cd) was investigated in dependence on mean transport temperature (923 K to 1223 K) and amount of transport agent Cl2. All tungstates migrate in a temperature gradient ΕT = 100 K from the region of higher temperature to the lower temperature with migration rates of 0.5 to 8 mg/h depending on experimental conditions. The transport behaviour was determined by continuous measurement of mass change during the transport experiments. The results were compared to thermo chemical calculations and the influence of moisture content discussed in detail. MgWO4 migrates under the influence of Cl2 in a temperature gradient 1273 K to 1173 K (migration rate 0.7 mg/h), CaWO4 and SrWO4 in a temperature gradient 1423 K to 1323 K (migration rate 0.1 mg/h).
- Steiner, Udo
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- On the mechanism of the metal exchange in natural cadmium porphyrins
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The kinetics of the exchange of the Cd2+ ions in the complexes with the natural protogroup porphyrins (protoporphyrin, mesoporphyrin, deuteroporphyrin, and hematoporphyrin) for the Zn2+ ions is studied. The stoichiometric ratios of components in the reaction of cadmium exchange for zinc in acetonitrile and DMSO are established. The results obtained are compared with the previously published data for the reaction withthe Co2+ ions. The activation mechanism of the metal exchange reaction is considered, depending on the effect of the nature of substituents in porphyrin, d-metal ions, and a solvent.
- Berezin,Zvezdina,Berezin
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- Synthesis, characterization and calorimetric study of zinc group halide adducts with aniline
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The adducts ZnCl2·2an, ZnBr2·1.5an, CdCl2·2an, CdBr2·2an, CdI2·2an, HgCl2·2an and HgBr2·2an (where an = aniline) were synthesized and characterized by elemental analysis, infrare
- da Silva Jr., Umberto G.,de Oliveira, ótom A.,de Farias, Robson F.
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- Second harmonic generation in boracites
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The M3B7O13X (M=Mg, Ni, Cd; X=Cl, Br, I) boracites were synthesized and characterized by x-ray diffraction and second harmonic generation. Their nonlinear optical susceptibility was estimated using the Phillips-Van Vechten
- Zagudailova,Plachinda,Berdonosov,Stefanovich,Dolgikh
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- Cd8As7Cl: A Novel Pnictidohalide with a New Structure Type
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A novel cadmium arsenide chloride, Cd8As7Cl (I), has been prepared by a two-step stoichiometric synthesis. It crystallizes in the cubic space groupP23 (No. 195) with a unit cell parametera=7.2660(10) A (Z=1). The crystal structure has been solved based on single-crystal X-ray diffraction data (ω-2θscans, least-squares refinement onF2) toR=0.0258 and wR2=0.0435. I possesses a new type of crystal structure that is described as a distorted (not dense) primitive cubic packing of cadmium atoms, the cubic voids of which are filled by either arsenic or chlorine atoms or As-As pairs. The structure of I exhibits a position disorder for one-half of the cadmium atoms. The As-As pairs are cubically surrounded by eight cadmium atoms, the As-As separation being 2.43 A, which is longer than in all known cadmium and mercury arsenide halides. Attempts to synthesize the corresponding bromide and iodide failed.
- Shevelkov, Andrei V.,Reshetova, Ludmila N.,Popovkin, Boris A.
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- Formation of cadmium chlorides via cadmium dissolution in chloride melts
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The kinetics and mechanism of the formation of complex Cd(I) ions via the reaction of metallic cadmium with Cd2+ ions in the Cd 0-CdCl2-ZnCl2-NH4Cl system are studied spectroscopically. The formation of Cd22+ and Cd23+ is evidenced by absorption bands around 270 and 335 nm, respectively, in the electronic spectrum of the melt. The anode current efficiency is determined for cadmium electrorefining in a chloride melt. A mechanism is proposed for the anodic dissolution of cadmium at different current densities and process temperatures. Pleiades Publishing, Inc., 2006.
- Kozin,Omel'chuk
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- Dielectric phase transition triggered by the order-disorder transformation of cyclopropylamine in a layered organic-inorganic halide perovskite
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Cyclic organic amines are emerging as excellent building blocks to assemble organic-inorganic hybrid phase transition materials due to their flexible cyclic structure. Herein, we used a three-membered ring organic amine, cyclopropylamine, assembling a layered organic-inorganic hybrid dielectric phase transition compound ([C3H5NH3]2[CdCl4], CPA) that displays a remarkable switchable dielectric response induced by an order-disorder transformation of the organic moiety. More specifically, the dielectric constant of CPA can be tuned between high- and low-dielectric states at ~273 K, which demonstrates its potential application in a switchable dielectric field. In addition, theoretical analysis of electronic band structures suggests that CPA exhibits a direct-band-gap with the value of 5.20 eV. This solid-state structural phase transition triggered by ordering of a three-membered ring organic amine is reported for the first time, and it highlights a new potential strategy to design switchable dielectric materials.
- Han, Shiguo,Liu, Xitao,Zhang, Jing,Ji, Chengmin,Wu, Zhenyue,Tao, Kewen,Wang, Yuyin,Sun, Zhihua,Luo, Junhua
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- [Cd2(Te6O13)][Cd2Cl 6] and Cd7Cl8(Te7O17): Novel tellurium(IV) oxide slabs and unusual cadmium chloride architectures
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Initial attempts to prepare new Ln-Cd-Te-O-Cl compounds led to the isolation of two novel cadmium tellurium(IV) oxychlorides with two different types of structures, namely, [Cd2(Te6O13)] [Cd2Cl6] and Cd7Cl8(Te 7O17). Both compounds feature novel polymeric tellurium(IV) oxide anions and unusual cadmium chloride substructures. The structure of [Cd2(Te6O13)][Cd 2Cl6] is composed of 1D [Cd2Cl 6]2- double chains and (002) [Cd2(Te 6O13)]2+ layers. The 1D Te6O 132- slab of the [Cd2(Te6O 13)]2+ layer is formed by TeO3, TeO 4, and TeO5 groups via corner- and edge-sharing, and it contains six- and seven-membered tellurium(IV) polyhedral rings. The structure of Cd7Cl8(Te7O17) features a 3D network with long-narrow tunnels along the b axis. The two types of structural building blocks are 1D [Te7O17]6- anions and unusual corrugated [Cd7Cl8]6+ layers based on cyclohexane-like Cd3Cl3 rings.
- Jiang, Hai-Long,Mao, Jiang-Gao
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- Energetics of formation of adducts of N-methyl-2-pyrrolidone with zinc(II) family metal halides - A thermochemical study
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Thermochemical data for adducts of N-methyl-2-pyrrolidone (NMP) with zinc(II), cadmium(II) and mercury (II) halides have been obtained from solution calorimetry. The technique provided the values for the dissolution enthalpies (ΔiH0) of MX2 (M = Zn, Cd, Hg; X = Cl, Br, I) metal halides, the NMP lactam and MX2.nNMP adducts, which were used to determine the standard molar enthalpies of acid-base reaction in the condensed state (ΔrH0) for the adducts, by using appropriate thermodynamic cycles. From ΔrH0 values and literature data, the following thermochemical parameters have been calculated: standard enthalpy of formation (ΔfH0), standard enthalpy of decomposition (ΔdH0), standard lattice enthalpy (ΔlattH0), standard enthalpy of acid-base reaction in the gaseous phase (ΔgH0) and the mean dissociation enthalpy of the metal-oxygen bond, D (M-O) have been established. In order to evaluate the methyl group influence on the donor oxygen strength of the NMP lactam, the obtained thermochemical data are compared with those previously published for analogous 2-pyrrolydone (BuL) compounds. The influence of the ionic and covalent character of the metal halides has been taken into account in the metal-oxygen interaction processes.
- Nunes, Ana L.C.,De Queiroz, Jose C.,Dias, Francisco S.,Vieira, Eunice F.S.
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- Solution and solid study of Zn(II) and Cd(II) complexes with N-(6-amino-3,4-dihydro-3-methyl- 5-nitroso-4-oxo-pyrimidin-2-yl)-glycine as ligand. Crystal structures of [ZnL2(H2O)4]·6H2O and {[Cd(μ-L)Cl(H2O)2]·H2O}(n)
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Reactions of N-(4-amino-1,6-dihydro-1-methyl-5-nitroso-6-oxo-pyrimidin-2-yl)glycine with Zn(II) and Cd(II) (1:1 and 1:4 metal/ligand ratios, in aqueous media at 35 °C and 0.1 M KCl ionic strength) were studied by potentiometric methods. This study has revealed a similar qualitative behaviour to that found by us for this family of N-pyrimidine aminoacids, the primary coordination site being either the pyrimidine or the carboxylate group depending on whether the ligand acts in neutral form or deprotonated, respectively. In solid state two complexes were obtained by working in 1:1 metal-to-ligand ratio: [Zn(L)2(H2O)4]·6H2O and {[Cd(μ-L)Cl(H2O)2]·H2O}(n), which were characterised by IR and NMR spectroscopies, TG and DSC techniques and single crystal X-ray diffraction. The former complex is mononuclear with the Zn(II) ion hexacoordinated in a distorted octahedral geometry. The coordination sphere is formed by four water molecules and two ligands coordinating in a monodentate fashion through the carboxylate group. The Cd(II) complex consists of a 1D infinite chain, with the metal ion heptacoordinated in a distorted pentagonal bipyramid. The ligand bridges the metal ions coordinating in a bis-didentate fashion through the pyrimidine and the carboxylate group. The nature of these complexes is very different to that shown by the Zn(II) and Cd(II) complexes with the related methionine derivative, which is attributed to he effect of the R substituent on the aminoacid moiety. (C) 2000 Elsevier Science S.A.
- Arranz-Mascarós,López-Garzón,Gutierrez-Valero,Godino-Salido,Moreno
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- Binding forms of gold(III) from solutions by cadmium diethyl dithiocarbamate: Thermal behavior and role of secondary interactions in the supramolecular self-assembly of polymeric Complexes ([Au{S2CN(C 2H5)2}2][AuCl4]) n and [Au{S2CN(C2H5) 2}Cl2] n
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The chemisorption interaction between the binuclear cadmium diethyl dithiocarbamate (EDtc), [Cd2{S2CN(C2H 5)2}4], (chemisorbent I) and AuCl3 solutions in 2 M HCl results in the formation of polymeric gold(III) complexes: ([Au{S2CN(C2H5)2} 2][AuCl4]) n (II) and [Au{S 2CN(C2H5)2}Cl2] n (III) with the same Au: EDtc: Cl ratio (1: 1: 2). The alternating centrosymmetric cations and anions of complex II are structurally self-assembled to form linear polymeric chains: the gold atom in [Au{S2CN(C 2H5)2}2]+ forms secondary Au(1)...Cl(1) bonds (3.7784 A) with two neighboring [AuCl 4]- anions. This binding is additionally strengthened by secondary S(1)...Cl(1) interactions (3.4993 A). The mixed-ligand complex III comprises two structurally non-equivalent molecules [Au{S 2CN(C2H5)2}Cl2]: A - Au(1) and B - Au(2), each being in contact with two nearest neighbors through pairs of unsymmetrical secondary bonds: Au(1)...S(1)a/b 3.4361/3.6329; and Au(2)...S(4)c/d 3.4340/3.6398 A. At the supramolecular level, this gives rise to independent zigzag-like polymeric chains, (...A...A...A...) n and (...B...B...B...) n along which antiparallel isomeric molecules of III alternate. The chemisorption capacity of cadmium diethyl dithiocarbamate calculated from the gold(III) binding reaction is 963.2 mg of gold per 1 g of the sorbent. The recovery conditions for the bound gold were elucidated by simultaneous thermal analysis of II and III. The DSC curves reflect different sets of heat effects, because thermolysis occurs for complex molecules (III) or for cations and anions (II). Nevertheless, the patterns of experimental TG curves are similar despite different structures of the complexes. The final product of thermal transformations is reduced gold.
- Rodina,Ivanov,Gerasimenko
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p. 100 - 108
(2014/03/21)
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- Thermal decomposition of complexes of cadmium(II) and mercury(II) with triphenylphosphanes
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A series of substituted triphenylphosphane complexes of the type CdL 2X2 (L= triorthotolylphosphane or trimetatolylphosphane; X=Cl-, Br- or I-) and HgL2X 2 (L=triphenylphosphane or triorthotolylphosphane) was prepared fresh. The thermal decomposition was carried out in air with heating rate programmed at 10°C min-1 and it revealed that the complexes with ortho derivative were less stable and the triphenylphosphane moiety leaves along with halogen in the first step. All the complexes were stable up to 210°C. However, the stability order of the tetrahedral complexes was X=Cl>Br. Values of n, E, lnA and ΔS # have been approximated and compared. Complexes having Br have higher E a, lnA and ΔS # values than that having Cl.
- Verma,Verma,Bhushan,Verma
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p. 725 - 729
(2008/10/09)
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- Cadmium(II) complexes of 1,2-di(imino-4′-antipyrinyl)ethane
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Cadmium(II) complexes of the Schiff base 1,2-di(imino-4′-antipyrinyl) ethane (GA) having general formulae [Cd(GA)]X2; (X = NO 3-, ClO4-) and [Cd(GA)X 2]; (X = Cl- Br- or I-) have been synthesized and characterized by elemental analysis, electrical conductance in non-aqueous solvents, infrared and electronic spectra as well as thermogravimetric analysis. In all these complexes, GA acts as a neutral tetradentate ligand coordinating through both the carbonyl oxygens and both the azomethine nitrogens. Both the anions are coordinated in the halide complexes while these remain as counter ions in the perchlorate and nitrate complexes. Thermal decomposition behavior of the nitrate complex indicates that it is stable up to 234°C and undergoes a three-stage decomposition pattern yielding the anhydrous Cadmium(II) oxide as the final residue. Copyright
- Deepa,Madhu,Radhakrishnan
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p. 883 - 888
(2008/10/09)
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- Thermal decomposition kinetics of some aniline complexes of zinc group metals
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The kinetics and mechanism of thermal decomposition of aniline complexes of zinc group metals have been studied using non-isothermal thermogravimetry. Kinetic parameters have been calculated for each of the decomposition stages using the Coats-Redfern equation. The mechanisms of the reactions have also been found out, and the rate controlling processes are found to be either random nucleation with the formation of one nucleus on each particle (Mampel equation) or phase boundary reaction with cylindrical symmetry or spherical symmetry.
- Sikha,Indrasenan
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p. 1393 - 1402
(2007/10/03)
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- On the chemistry of fluoroorgano derivatives of group 13 elements. 2: Synthesis and characterization of the 1:1-adducts of In(C6F5)3 with acetonitrile, glyme, and DMAP (DMAP = 4-(N,N-dimethylamino)-pyridine), and [PNP][In(C6F5)4](PNP = bis(triphenylphosphinanyliden)-immonium)
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In(C6F5)3 · CH3CN and In(C6F5)3 · glyme were synthesized from InCl3 and Cd(C6F5)2 in CH3CN or glyme in 43% and 35% yield, respectively. Replacement of CH3CN or (C2H5)2O by DMAP yielded the corresponding 1:1-adduct. [PNP][In(C6F5)4] was best prepared from the corresponding cesium salt which was best synthesized from the reaction of stoichiometric amounts of In(C6F5)3 · CH3CN, (CH3)3 SiC6F5 and CsF in good yield. _[PNP][In(C6F5)4] crystallizes in the triclinic space group P1, a = 1104.9(4) pm, b = 1442.4(6) pm, c = 1833.8(8) pm, α = 110.87(2)°, β = 92.04(3)°, γ = 96.55(3)°, Z = 2.
- Choi, Zel-Ho,Tyrra, Wieland,Adam, Arnold
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p. 1287 - 1292
(2008/10/08)
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- Transition metal complexes with pyrazole-based ligands. Part 6. Synthesis, characterization and thermal decomposition of cadmium complexes with 3(5)-amino-5(3)-methylpyrazole
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The synthesis, IR spectra and thermal analysis of tetrahedral or octahedral Cd(II)-complexes of 3(5)-amino-5(3)-methylpyrazole (L), as represented by the general formula CdX2L2.nH2O (X = NCS(1-), NCO(1-), Cl(1-), n =2; 1/2SO4(2-), n = 1), and of the complex Cd(OASc)2L3.H2O are described . Thermal decomposition of the acetato complex results in an intermediate, appearing in the 480-580 K range. On the basis of the IR-spectrum andthe results of elemental analysis of the intermediate, a decomposition scheme is proposed. Because of the involvement of a different anion, the thermal decomposition of the other complexes differs from that of the a cetato complex.
- Szecsenyi, K. Meszaros,Iveges, E. Z.,Leovac, V. M.,Vojinovic, Lj. S.,Kovacs, A.,et al.
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- Orthorhombic Phase of Cadmium Phosphochloride Cd3PCl3: Crystal Structure
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X-ray crystal structure of the orthorhombic phase of Cd3PCl3 synthesized by the ampule technique is determined (space group Pnma, a = 13.028(4) ?, b = 7.957(3) ?, c = 7.0050(10) ?, V = 726.2(4) ?3, Z = 4). The structure of this phase is based on a distorted two-layer stacking of chlorine and cadmium atoms, in which half of the octahedral sites and 1/8 of the tetrahedral sites are occupied in an orderly way by cadmium atoms. The structural difference between the orthorhombic and hexagonal phases of Cd3PCl3 is determined. Analysis of the crystal structure of cadmium and zinc pnictide halides of the general formula M3ZX3 (where M = Zn or Cd, Z = P or As, X = Cl or I) shows that the structure type of these compounds depends on the size of the halogen atom.
- Shevel'kov,Dikarev,Popovkin
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p. 1121 - 1123
(2008/10/08)
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- Preparations and properties of tris(perfluoroalkyl) arsenic and antimony(III, V) compounds
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As(Rf)3 and Sb(Rf)3 (Rf = C2F5, C4F9, C6F13) are prepared in good yields by the polar reactions of AsCl3 and SbCl3/su
- Naumann, Dieter,Nowicki, Gabriele,Sassen, Karl-Josef
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p. 1183 - 1189
(2008/10/09)
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- Thermal investigation and stereochemical studies of some cyclic diamine complexes of nickel(II), zinc(II) and cadmium(II) in the solid state. Part III
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Monochloroacetato (MCA) cyclic diamine (piperazine (pipz); N-methylpiperazine (mpipz); 1,4-diazacycloheptane (dach)) complexes of nickel(II), zinc(II) and cadmium(II) were synthesized. A thermal investigation was carried out and the stereochemical changes which occurred during thermal decomposition were studied. The complexes were characterized with the help of elemental and thermal analyses and IR spectral and magnetic moment data. They were found to have the compositions: [Ni(pipz)(MCA)2(H2O)2], [NiL2(MCA)2]·2H2O (L =mpipz or dach), [Zn(pipz)(MCA)2]·H2O, [Zn(mpipz)(MCA)2]·2H2O, (Zn(dach)(MCA)2], [Cd(pipz)2(MCA)2]·2H2O and [CdL2(MCA)2] (L = mpipz or dach). Attempts to prepare N,N'-dimethylpiperazine complexes failed. Configurational and conformational changes were studied using thermal analysis and IR spectral and magnetic moment (in the case of nickel(II) complexes) data. All the complexes of nickel(II) and cadmium(II) appeared to possess an octahedral structure, whereas those of zinc(II) appeared to be tetrahedral. Thermodynamic parameters such as activation energy Ea, enthalpy change ΔH and entropy change ΔS for the dehydration and decomposition reactions of the complexes were evaluated using some standard methods. The order of stability of the complexes (with respect to Ea) follows the trend pipz ? mpipz ? dach. A linear correlation obtained by plotting Ea> vs. ΔS shows that a system with a higher entropy change ΔS will require less energy Ea for decomposition.
- Singh, Langonjam Kanhai,Mitra, Samiran
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- Preparation, characterization, and structural aspects of transition-metal complexes with 4,7,10-trioxa-1,13-dithia[13](2,5)-1,3,4-thiadiazolophane
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The title compound 5 readily forms discrete 2:1 (ligand to metal) complexes with Cu(II), Co(II), and Ni(II) nitrates and with CuBr2 and a highly crystalline polymeric 2:3 (ligand to metal) complex with CdCl2. The complexes have been characterized by chemical analysis, FAB mass spectrometry, 1H NMR spectroscopy (for the diamagnetic Cd(II) complex 10), electronic spectral studies, and EPR spectroscopy. Structures of the free ligand and its complexes with CuBr2 and CdCl2 have also been determined. X-ray crystal structure determinations have shown that the macrocyclic ligand does not accommodate the metal ions inside the cavity but rather coordinates on the exterior through a nitrogen atom(s). The heterocyclic ring acts as a monodentate ligand in the trans square-planar Cu(II) complex 9 and as a bridging bidentate ligand in the octahedral Cd(II) complex 10. Cd atoms in 10 are linked through bis(μ-chloro) bridges into infinite chains, the macrocyclic units serving as bridging ligands through the two nitrogen atoms. C10H16N2O3S3 (5) is tetragonal, P41212 (or P43212), with a = 9.3369 (11) A?, c = 15.761 (2) A?, Z = 4, and R = 0.027 for 1653 observations. CuBr2(C10H16N2O3S 3)2 (9) is triclinic, P1, with a = 8.3452 (13) A?, b = 9.2414 (10) A?, c = 11.7586 (8) A?, α = 71.313 (7)°, β = 78.347 (9)°, γ = 63.120 (12)°, Z = 1, and R = 0.043 for 3033 observations. Cd3Cl6(C10H16N2-O 3S3)2·2CH3OH (10) is triclinic, P1, with a = 10.133 (3) A?, b = 10.187 (2) A?, c = 11.740 (2) A?, α = 72.834 (11)°, β = 68.327 (15)°, γ = 63.52 (2)°, Z = 1, and R = 0.020 for 3206 observations.
- Bonomo, Raffaele,Bottino, Francesco,Fronczek, Frank R.,Mamo, Antonino,Pappalardo, Sebastiano
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p. 4593 - 4598
(2008/10/08)
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- COMPLEXES OF GROUP IIb METALS WITH DITHIOOXAMIDES V - VIBRATIONAL SPECTRA AND THERMAL ANALYSIS OF THE CdLX2 COMPLEXES
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In acid media, CdX2 forms non-electrolyte CdLX2 (L=DTO, NN'DMDTO, TMDTO; X=Cl, Br, I) complexes with dithiooxamides.The ligands act as bidentates with S,S coordination.A thorough vibrational analysis (i.r. and Raman) has been performed for the Cd(H2NCSCSNH2)X2 (X=Cl, Br, I), the Cd(CH3NHCSCSNHCH3)X2 (X=Br, I) and the CdX2 (X=Cl, Br, I) complexes, by NH/ND and CH3/CD3 isotopic substitution.Stereochemistries varying from tetrahedral to octahedral structures are proposed based on spectroscopic evidence and the positions of the metal-ligand vibrations can be explained in terms of the HSAB principle.The thermal behaviour of the complexes has been studied, using isothermal as well as non-isothermal techniques.
- Geboes, Peter,Plakatouras, John,Desseyn, Herman O.
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p. 821 - 832
(2007/10/02)
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- Etude des complexes et fluores et chlores du cadmium dans les melanges eau-HF
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The formation of fluoride and chloride complexes in water-hydrogen fluoride mixtures has been studied using polarography.The reduction of the complexation by the fluoride ions from CdF3- down to CdF+ is in good agreement with the reduction of the fluoride ion activity, R0(F) with increasing HF concentration.At higher HF concentration than 60percent, the half-wave potential for the reduction of cadmium is shifted in a pattern that cannot be explained by flluoride in complexation.The formation of CdCl3- and CdCl42- has been observed in H2O-HF-KCl mixtures when the HF concentration was increased to 60percent.
- Beaudoin, Rejean,Menard, Hugues
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p. 236 - 241
(2007/10/02)
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- Nicotine Complexes of Zinc(II), Cadmium(II) and Mercury(II)
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Complexes of nicotine(nic), M(nic)nX2 (M = Zn or Cd; n = 2, X = Cl, Br, I or NCS; M = Hg, n = 1, X = Cl, Br or I) have been prepared.The conductivity measurements indicate that the complexes are nonionic.The complexes have been characterised on the basis of analytical, IR and PMR spectral, and thermal studies.
- Muralidharan, S.,Udupa, M. R.,Nagaraja, K. S.
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- Light-sensitive diazonium trifluoromethane sulfonates
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Provided are light-sensitive diazonium compounds known as diazonium trifluoromethane sulfonates, which have the structural formula: STR1 wherein D --N=N-- is the cation of a light-sensitive, aromatic diazonium compound. The diazonium trifluoromethane sulfonates are prepared as the reaction product of trifluoromethyl sulfonic acid, or a salt thereof, and a diazonium compound. Said diazonium trifluoromethane sulfonates find utility in diazography formulation for both positive- and negative-working diazotype photoreproduction systems, and as latent polymerization initiators activatable by irradiation.
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