- New organically templated thiocyanatocadmates and chlorocuprate(ii): synthesis and structural characterization
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With various organic base molecules as the countercations, five new thiocyanatocadmates [H2(tmen)][Cd(SCN)4] (tmen = N,N,N′,N′-tetramethylethylenediamine) 1, [H2(tmba)][Cd2(SCN)6] (tmba = N,N,N′,N′-te
- Guo, Bing,Zhang, Xiao,Yu, Jie-Hui,Xu, Ji-Qing
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- A thermochemical study of adducts of 2-pyrrolidone with zinc(III), cadmium(II) and mercury(II) halides
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The standard molar enthalpies of acid-base reactions in the condensed state (Δ(r)H(0)) of the adducts MX2 . nBuL (where M is Zn, Cd, Hg; Xis Cl, Br, I; n = 1, 2, 3; BuL is 2-pyrrolidone) were determined from e nthalpies of dissolution (Δ(i)H(0)) of metal halide ligands and adducts, at 298.15 K, obtained by calorimetric methods in solution. Using the values of Δ(r)H(0) and auxiliary data from the literature the standard enthalpies of formation (Δ(f)H(0)), decomposition (Δ(d)H(0)) and lattice enthalpy (Δ(latt)H(0)) of these adducts weredetermined. The enthalpy of vaporization of BuL, Δ(vap)H(0)(BuL), was found to be 41.71+/-0.56 kJ mol**-1 and, from this value, the entha lpies of reaction in the gaseous state (Δ(g)H(0)) were estimated. The values of Δ(g)H(0) were used in calculations of the mean dissociation enthalpy of the metal-oxygen bond, D(M-O), of the obtained adducts, and are correlated with energetic parameters of the metal halides.
- Vieira, Eunice F. S.,Queiroz, Jose C. de,Dias, Francisco S.
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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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- Investigation on the thermal decomposition some heterodinuclear Ni II-MII complexes prepared from ONNO type reduced Schiff base compounds (M II=ZnII, CdII)
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N,N'-bis(salicylidene)-1,3-propanediamine (LH2), N,N'-bis(salicylidene)-2,2'-dimethyl-1,3-propanediamine (LDMH2), N,N'-bis(salicylidene)-2-hydroxy-1,3-propanediamine (LOH3), N,N'-bis(2-hydroxyacetophenylidene)-1,3-propanediamine (LACH2) and N,N'-bis(2-hydroxyacetophenone)-2,2'-dimethyl-1,3-propanediamine (LACDMH 2) were synthesized and reduced to their phenol-amine form in alcoholic media using NaBH4 (LHH2, LDM HH2, LOHHH2, LACHH 2 and LACDMHH2). Heterodinuclear complexes were synthesized using Ni(II), Zn(II) and Cd(II) salts, according to the template method in DMF media. The complex structures were analyzed using elemental analysis, IR spectroscopy, and thermogravimetry. Suitable crystals of only one complex were obtained and its structure determined using X-ray diffraction, NiLACH?CdBr2?DMF2, space group orthorhombic, Pbca, a=20.249, b=14.881, c=20.565 A and Z=8. The heterodinuclear complexes were seen to be of [Ni?ligand?MX 2?DMF2] structure (ligand=LH2-, LDM H2-, LOHH2-, LACH2-, LACDMH2-, M=ZnII, CdII, X=Br-, I-). Thermogravimetric analysis showed irreversible bond breakage of the coordinatively bonded DMF molecules followed by decomposition at this temperature.
- Aksu,Durmus,Sari,Emreguel,Svoboda,Fuess,Atakol
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p. 541 - 547
(2008/10/09)
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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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- 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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- Thermodynamic Properties of PbBr2-CdBr2 and PbBr 2-CdBr2-KBr Melts
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The temperature dependence of the saturation vapor pressure in the PbBr2-CdBr2 and PbBr2-CdBr2-KBr systems was studied using the boiling-point method. The obtained results were used to calculate the vapor composition and the thermodynamic characteristics for the systems under study.
- Burylev,Moisov,Kritskaya,Kostenko
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p. 2076 - 2078
(2007/10/03)
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- Thermal studies and vibrational analyses of m-methylaniline complexes of Zn(II), Cd(II) and Hg(II) bromides
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The complexes having the MBr2L2 (M: Zn, Cd and Hg; L: m-methylaniline) formulae have been prepared and characterized by their elemental analyses, thermogravimetric analyses, IR and Raman spectral studies. IR and Raman bands of the complexes have been assigned as compared with the free ligand. Coordination effects on the internal modes of m-methylaniline have been discussed. Vibrational spectra propose that the [ZnBr2(mMA)2] complex is in a tetrahedral environment around Zn(II) ion with C2v symmetry whereas Cd(II) and Hg(II) complexes have 5-coordinate polymeric bromide bridged structures.
- Golcuk,Altun,Kumru
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p. 1841 - 1847
(2007/10/03)
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- Cd5P2Br4: First Cadmium Analogue of the Millon's Base Salts
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A new cadmium pnictide halide - Cd5P2Br4 - was synthesized, and its structure was determined (R = 0.0525). The compound crystallizes in the orthorhombic symmetry system, space group Pna21 (a = 12.189 ?, b = 7.7080 ?, c = 13.664 ?, Z = 4). A characteristic feature of the Cd5P2Br4 structure is a distorted tridymite-type framework composed of cadmium and phosphorus atoms. The framework cavities accommodate discrete tetrahedral groups CdBr4. Such a structure makes it possible to classify the new compound as the first cadmium-phosphorus analogue of Millon's base salts. The structure of Cd5P2Br4 is compared to the structure of Hg5P2Br4, another phosphorus-containing analogue of Millon's base salts.
- Shatruk,Reshetova,Shevel'kov,Popovkin
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p. 495 - 499
(2008/10/08)
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- Synthesis and crystal structure of Cd2SbBr2
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New cadmium bromoantimonide Cd2SbBr2 is prepared by the standard tube method. Its crystal structure is solved by the direct methods and refined to R = 0.0328 for 1374 independent reflections and 69 variable parameters. The compound crystallizes in the monoclinic space group P21: a = 8.244(1), b = 9.920(1), c = 8.492(1) A, β = 116.80(1)°. The presence of binuclear Sb24- anions (Sb-Sb = 2.78 A) with an octahedral environment comprised of six cadmium atoms is the most interesting feature of the structure. The Sb2Cd6 octahedra share equatorial vertices to form layers. The layer alternation motif is close to that reported for cadmium and mercury chloroarsenides.
- Reshetova,Shevel'kov,Popovkin
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p. 819 - 822
(2008/10/09)
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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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- 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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p. 282 - 285
(2008/10/08)
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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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p. 165 - 175
(2008/10/09)
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- The Catalytic Life of CdBr2-KBr and Its Affect on the Rate of Indole Formation from Aniline and Ethylene Glycol
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In the liquid-phase synthesis of indole from aniline and ethylene glycol (EG), a CdBr2-KBr catalyst gave a high yield of indole.In recycling experiments using the catalyst in an autoclave, the yield of indole remained stable and the inorganic comonents of the catalysts did not suffer degeneration.The time course of the reaction under pressure and high temperature was evaluated using a newly devised autoclave.The rate of formation of indole was determined to be proportional to the concentrations of both EG and the catalyst.Based on these findings for the reaction over CdBr2-3KBr, it is clear that this catalyst provides a simple and low-cost catalytic process for the formation of indole.
- Seto, Takatoshi,Kujira, Katsufumi,Iwane, Hiroshi,Imanari, Makoto
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p. 3665 - 3670
(2007/10/03)
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- Reactions of sterically hindered organozinc and organocadmium compounds containing functional silicon centres. Crystal structures of Zn2 and Cd2
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The compound (Me3Si)2CCl2 was converted by treatment with BuLi/Et2O/THF and then with Me2HSiCl into (Me3Si)2CCl(SiMe2H).Further lithiation with BuLi gave LiC(SiMe3)2(SiMe2H), which reacted with ZnBr2 to yield Zn2.Thence, several new org
- Al-Juaid, Salih S.,Eaborn, Colin,Habtemariam, Abraha,Hitchcock, Peter B.,Smith, J. David
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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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- 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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- 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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- 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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p. 2981 - 2983
(2007/10/02)
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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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- 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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p. 2379 - 2384
(2008/10/08)
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