- Synthesis and structure determination of two neutral cadmium thiophenolate clusters
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The polynuclear complexes [Cd8S(SPh)14(DMF) 3] (1) and [Cd17S4(SH)2(SPh) 24(PPh3)2] (2) were prepared by an organometallic synthesis route. X-ray diffraction on single-crystals revealed a hexagonal closed packing of the cluster unit in 1 in the triclinic space group P1. Compound 2 crystallized in the monoclinic space group C2/c. In contrast to related cluster compounds, the ligand sphere of 1 is expanded resulting in an unusual trigonal-bipyramidal coordination of one of the cadmium ions. The heterogeneous composition of the ligand sphere of 2 results in the formation of individual cluster molecules. Copyright
- Gruber, Franziska
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- Thermal decomposition of Cd(CH3COO)2· 2H 2O studied by a coupled TG-DTA-MS method
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The thermal decomposition of cadmium acetate dihydrate in helium and in air atmosphere has been investigated by means of a coupled TG-DTA-MS method combined with X-ray diffraction analysis. Dehydration of Cd(CH 3COO)2·2H2O is a two-stage process with Cd(CH3COO)2H2O as intermediate. The way of Cd(CH3COO)2 decomposition strongly depends on the surrounding gas atmosphere and the rate of heating. CdO, acetone and CO 2 are the primary products of decomposition in air. In helium decomposition goes by two parallel and consecutive reactions in which intermediates, Cd and CdCO3, are formed. Metallic cadmium oxidizes and cadmium carbonate decomposes giving CdO. Some of the metallic cadmium, depending on the heating rate and the concentration of oxygen, evaporates. Acetone is partially oxidized in secondary reactions with oxygen.
- Malecka, Barbara
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- Electrochemical synthesis of cadmium(II) carboxylates compounds at sacrificial cadmium anode
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Cadmium carboxylates and their coordination complexes are synthesized by using an electrochemical technique in the presence of different carboxylic acids (RCOOH) using cadmium and a platinum as the anode and cathode respectively and tetrabutyl ammonium chloride as a supporting electrolyte. The electrochemical oxidation of anodic cadmium in acetonitrile solution with different carboxylic acids or with 1,10-phenanthroline (phen) and 2,2'-bipyridyl (bipy) yield the complexes Cd(OOCR)2 and Cd(OOCR)2L (L = phen or bipy), respectively. The results from spectroscopic studies FTIR, elemental analysis and physical measurements confirm the existence of bonding between the carboxylate groups of different carboxylic acids with cadmium. Current efficiencies of all these synthesized compounds are also discussed.
- Bala, Kanchan,Singh, Baljit
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p. 336 - 340
(2017/01/24)
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- Reactions of Cd(OAc)2·2H2O with variously substituted pyridines. Efforts to unravel the factors that determine structure/nuclearity of the products
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The reactions of Cd(OAc)2·2H2O with variously substituted pyridines in methanol afforded unique one-dimensional coordination polymers (1D CPs), [Cd2(μ2-κ2:κ1-OAc)2(μ2-κ1:κ1-OAc)2L2] (L = NC5H5 (1), NC5H4Me-3 (2), and NC5H3Me2-3,5 (3)) and [Cd3(μ3-κ1:κ2-OAc)3(μ2-κ2-OAc)(μ2-κ2:κ1-OAc)2(NC5H3Me2-3,4)2] (4), and discrete and bimolecular complexes, [(Cd(OAc)2(NC5H3Me2-3,4)2(H2O)2] (5), [Cd(κ2-OAc)2(NC5H4Me-4)2(H2O)]·[Cd(κ2-OAc)2(H2O)2)] (6), [Cd(κ2-OAc)2L2L′]·xH2O (x = 0, L′ = H2O, L = NC5H4(OMe)-4 (7); NC5H4tBu-4 (8); x = 2, L = L′ = NC5H4(NMe2)-4 (9·2H2O)). The products were characterised by elemental analysis, IR, solution NMR (1H and 13C), solid-state CP-MAS 13C{1H} and 113Cd NMR, TGA/DTA analyses, and single crystal X-ray diffraction. Phase purity of 1-4 was verified by powder X-ray diffraction (PXRD). Plausible mechanisms of formation of the products are proposed based on a point zero charge model. 4 represents the first cadmium containing 1D CP that possesses a tridentate bridging (μ3-κ1:κ2) acetate coordination mode and 6 represents the first structurally characterised bimolecular cadmium(II) complex containing two different neutral cadmium(II) coordination species per formula unit. 9·2H2O was calcined at 500 °C to afford CdO as confirmed by PXRD and the morphology of CdO was studied by scanning electron microscopy.
- Saxena, Priya,Thirupathi, Natesan
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supporting information
p. 238 - 250
(2015/07/27)
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- Highly-improved performance of TiO2 nanocrystal based quantum dot light emitting diodes
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We have fabricated quantum dot based light emitting diodes (QLEDs) with 3 nm-titanium oxide (TiO2) nanocrystals used as the electron transport layer (ETL). Different thicknesses of TiO2 films were fabricated under the post-annealing conditions (at 100°C) from 30 min to 120 min, leading to significantly enhanced electrical characteristics and increased luminance intensity of the QLED device due to better crystallization of TiO 2 films. The blue shift of the electroluminescence (EL) peak was observed as evidence of the enhanced electron injection from the TiO2 film to the quantum dot emission layer. As a result, the highly stable QLED device was fabricated and the EL intensity was improved from 25 cd m -2 to 390 cd m-2 with a 49% decrease in the turn-on voltage. The Royal Society of Chemistry 2013.
- Qasim, Khan,Chen, Jing,Li, Zhi,Lei, Wei,Xa, Jun
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p. 12104 - 12108
(2013/09/02)
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- Precursors for mixed metal oxide nanoparticles: Synthesis and characterization of μ-oxoalkoxides of some bivalent metals and their β-diketonates
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New heterobimetallic derivatives of the type M{OAl(OPri) 2}2 (M = Sn, Pb, Cd) have been prepared by the reactions of M(OAc)2 with Al(OPri)3 in 1:2 molar ratio in hydrocarbon solvent (xylene/toluene) with the continuous liberation of isopropyl acetate. Furthermore, reactions of M{OAl(OPri) 2}2 (M = Ca, Pb, Cd) with β-diketones (acetylacetone, benzoyl acetone) have also been carried out to obtain modified derivatives. These new derivatives have been characterized by elemental analyses and spectroscopic [IR, NMR (1H, 13C, 27Al and 119Sn)] studies.
- Sharma, Malti,Bhagi, Ajay K.,Sharma, Harish K.,Priti, Ritu Kansal,Kumar, Ram,Kapoor, Pramesh N.
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p. 256 - 260
(2007/10/03)
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- Spectropotentiometric Study of the Complexation Equilibrium in the H2TAP(Br)4 H2TAP(Cl)4-(CH3COO)2Cd-HClO 4-DMSO System at 298 K
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A method for the direct measurement of the equilibrium constant of reaction for the formation of porphyrin complexes is proposed. According to this method, the equilibrium in the reaction MX2 + H2P R1 ? R-1 MP + 2HX is established under the condition that the forward reaction (R1) is suppressed, whereas the back reaction (R-1) is initiated. The applicability of this method to the formation of Cd2+ complexes with tetrachloroand tetrabromotetraazaporphyrins in DMSO in the presence of HClO4 is demonstrated.
- Ivanova,Simonova,Sheinin,Chizhova,Berezin
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p. 1611 - 1615
(2008/10/08)
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- Ultrasonic Absorption Study of the Complex Formation of Cadmium(II) Carboxylates in Aqueous Solution
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Ultrasonic absorption of aqueous cadmium(II) acetate, propionate, and n-butyrates has been measured with a pulse technique over a frequency range 3-260 MHz.The single relaxations observed in the metal-rich concentration regions are attributed to the complex formation of cadmium(II) carboxylates via the Eigen-Tamm mechanism of stepwise association.The reaction parameters are determined from the concentration dependences oh the relaxation frequency and amplitude.The association constant for outer-sphere complexing and the rate constant for ligand substitution lie in the range 0.91-1.14 and (4.1-5.4) * 108 s-1, respectively, both being almost independent of the nature of the carboxylate ions, in contrast to the zinc(II) carboxylates previously reported.The volume changes of the outer-sphere complexing and those of the ligand substitution are determined to be 1.7-2.4 and 4.6-6.7 cm3 mol-1, respectively; these values are very different from those of cadmium(II) thiocyanate reported earlier.
- Tamura, Kiyoshi
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p. 3425 - 3429
(2007/10/02)
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