Cadmium Perchlorate Research Articles

Pillared, 3D metal-organic frameworks with rectangular channels. Synthesis and characterization of coordination polymers based on tricadmium carboxylates.

Hydro(solvo)thermal reactions between cadmium(II) perchlorate and 4-pyridinecarboxaldehyde in the presence of various guest molecules have resulted in a series of 3-D coordination polymers based on tricadmium carboxylates [Cd6(isonicotinate)10(H2O)2](ClO4)2(EtOH)4(H2O)4, 1, [Cd3(isonicotinate)5 (EtOH)](ClO4)(EtOH)(4-nitroaniline)0.5, 2, and [Cd6(isonicotinate)11](ClO4)(EtOH)2(H2O)2(4-cyanopyridine)0.5, 3. X-ray single crystal structure determinations show that they exhibit similar pillared, 3D framework structures based on tricadmium carboxylate building blocks. Rectangular channels are clearly present in these polymeric networks and are occupied by perchlorate anions and disordered guest molecules. Quantitative NMR and X-ray powder diffraction studies and thermogravimetric analyses (TGA) reveal that these coordination networks are capable of accommodating different guest molecules. More significantly, the guest molecules can be readily removed via evacuation to result in nanoporous polymeric coordination networks retaining the framework structures of the pristine solids. Crystal data for 1: monoclinic space group P2(1)/n, a = 19.041(1) A, b = 23.654(1) A, c = 21.568(1) A, beta = 95.440(1) degrees, and Z = 4. Crystal data for 2: triclinic space group P1, a = 12.050(1) A, b = 12.277(1) A, c = 19.103(1) A, alpha = 91.669(1) degrees, beta = 96.850(1) degrees, gamma = 117.945(1) degrees, and Z = 2. Crystal data for 3: monoclinic space group P2(1)/n, a = 19.038(1) A, b = 23.834(1) A, c = 21.756(1) A, beta = 97.580(1) degrees, and Z = 4.

Towards rational synthesis of polar solids. Synthesis and X-ray structures of cadmium(II) meta-pyridinecarboxylate coordination polymers †

Two cadmium(II) coordination polymers, Cd2L14(μ-H2O) 1 and Cd2L24(μ-H2O) 2 [L1 = (E)-4-(2-thiazolyl)ethenylbenzoate, L2 = (E)-4-(3-pyridyl)ethenylbenzoate] based on meta-pyridinecarboxylate bridging ligands, were synthesized by the reactions of cadmium perchlorate and the corresponding benzonitrile precursor ligands under hydro(solvo)thermal conditions. Although both compounds 1 and 2 are constructed from the Cd2Ln4(μ-H2O) building block, X-ray single crystal structure determinations show that 1 adopts a 2-D polymeric network structure while 2 exhibits a 3-D framework structure as a result of the slightly different configurations of the bridging pyridinecarboxylate ligands. Owing to the presence of the bridging water molecules, both 1 and 2 crystallize in centrosymmetric space groups.

Wet Chemical Synthesis of Highly Luminescent HgTe/CdS Core/Shell Nanocrystals

We have recently reported the wet chemical synthesis of colloidal HgTe nanocrystals in aqueous solution at room temperature. This novel material exhibits very strong and broad photoluminescence (PL) in the near infrared, with the exact wavelength depending on the synthetic conditions. The preparation was an extension to the previously published work on cadmium chalcogenide nanocrystals, i.e., CdS, CdSe, and CdTe, and used 1-thioglycerol as the size-regulating capping agent. Particles with a large distribution of sizes in the 3±6 nm diameter range were produced. Luminescence quantum efficiencies (QEs) of around 50 %, which are among the highest ever reported for a colloidal system, and stability towards oxidation indicate that the surface of the HgTe nanocrystals is extremely well-passivated. Typically, the PL from the freshly prepared material is around 1050 nm, but this moves to longer wavelengths with time, accompanied by an apparent drop in QE, until after two weeks the luminescence has shifted out to around 1200 nm. This aagingo process continues indefinitely, albeit at a slower rate, and presents real cause for concern for the long-term stability of such materials in device applications. In addition, if the colloidal nanocrystal solutions are heated, then a similar but more rapid process occurs with the PL shifting to beyond 1500 nm and the QE dropping to < 1 % with just a few minutes refluxing at 100 C. Again, this lack of stability to heating could be problematic in certain applications if high optical pump powers are used in laser or amplifier devices. A similar, although less-pronounced, effect is also observed in 1-thioglycerol-stabilized CdTe nanoparticles, which undergo a red shift of the PL under prolonged reflux. Whether this shift is caused by a gradual aripeningo of the nanocrystals with heat and/or time, or actually represents a compositional change will be discussed at a later date. Needless to say, the effect is undesirable and for HgTe to be a useful material, operating at the strategic near-infrared telecommunications wavelengths, the problem has to be eliminated. A possible way of achieving this is to cap the surface of the nanocrystals with a higher bandgap inorganic layer. These acore/shello composite materials can increase the luminescence quantum yield due to improved passivation of the surface, and also tend to be more physically robust than the abareo organically passivated clusters. This should therefore produce a much more stable material where not only the aagingo process is suppressed, but which is more tolerant to the processing conditions necessary for incorporation into useful devices. Examples of such core/shell structures include CdSe/ZnS, CdS/ZnS, CdSe/CdS, CdSe/ZnSe, and CdS/HgS with reports of roomtemperature QEs of up to 50 % for the CdSe/ZnS material. It was therefore decided to attempt to overcoat our HgTe nanocrystals with a layer of CdS in order to produce a physically stable core/shell heterostructure. The abareo 1-thioglycerol-stabilized HgTe colloidal nanocrystals were prepared in aqueous solution at room temperature using the method described previously. In order to coat these abareo organically capped nanocrystals with a layer of CdS, H2S gas buffered in N2 was passed through a vigorously stirred, dilute aqueous solution of HgTe nanocrystals and cadmium(II) perchlorate at a pH of around 10 in the presence of extra 1-thioglycerol stabilizer. The mixture was initially slightly turbid, but this cleared upon injection of the H2S, resulting in a clear, goldenbrown solution. This solution was then refluxed for about 30 min as a check of the robustness of the HgTe/CdS system. In order to fully characterize the material, optical absorption and photoluminescence spectra were recorded at all stages of the synthesis, as well as X-ray diffraction (XRD) patterns and high-resolution transmission electron microscopy (HRTEM) images to confirm the presence of HgTe/CdS core/shell particles in the final solution. The optical absorption data is shown in Figure 1, comparing the freshly prepared abareo HgTe prior to capping, and the subsequent HgTe/CdS material. A clear aexcitonico peak is visible for the bare HgTe sample at 850 nm, which clearly shifts to the red when the CdS capping is introduced. The increased optical density at shorter wavelengths could be indicative of some discrete CdS or HgCdTeS alloyed nanoparticles being formed in addition to the core/shell material. The effect of aging and/or heating the samples, both capped and uncapped, is to red-shift and broaden the absorption edges into the region where water absorption caused by a slight cell-mismatch prevents the recording of good-quality spectra. These are, therefore,

The temperature dependence of EPR spectra of Cu(II)-doped hexakis(imidazole)cadmium(II) perchlorate

EPR spectra of powder samples of Cu(II)-doped Cd(Im) 6(ClO 4) 2 are studied at X-band over a wide temperature range, 7–300 K. The observed g and copper hyperfine tensors are found to be strongly temperature dependent and are interpreted in terms of Jahn–Teller effect involving a d x 2− y 2 ground state. Single crystal spectra indicate the presence of two misaligned elongated tetragonal octahedral CuN 6 chromophores. The g tensor of Cu(II)-doped Cd(Im) 6(ClO 4) 2 is axially symmetric, implying that the orthorhombic strain component is insignificant. Influence of the structure of host crystals on the observed behaviour is discussed by comparing the EPR results of Cu(Im) 6 2+ in different lattices.

Schiff-Base Podates – X-ray, NMR and Ab Initio Molecular-Orbital Studies of the Cadmium(II) Complexes of Linear and Three-Armed Podands in Solution and Solid State

Cadmium(II) complexes of two Schiff bases, 1,3-di(pyridine-2-carboxaldimino)propane (C15H16N4, L1)[1] and tris[4-(2′-pyridyl)-3-aza-3-butenyl]amine (C24H27N7, L2)[2] are described. An efficient route utilising molecular sieves for the synthesis of Schiff bases is presented. The ligands L1 and L2 can be described as linear and three-armed podands, respectively, L1 being conformationally flexible and L2 preorganised. Cadmium perchlorate in methanol with L1 yields a crystalline complex [Cd(L1)2](ClO4)2 (1), the structure of which was determined by X-ray structure analysis. The complex 1 has an unusual nonsymmetrical 8-coordinated helical structure and crystallizes in an acentric space group (Cc, no. 9) as a pure enantiomer due to spontaneous resolution. Solution studies of 1 in CHCl3/DMSO (10:1) and pure DMSO were performed using 1H-, 13C-, 113Cd-NMR and 1H,15N z-GS HMBC spectroscopy and they suggest a reorientation of 1 into the more symmetrical 4-coordinate complex due to the flexible nature of L1. The preorganised, potentially tetra-, hexa- or heptadentate, three-armed podand L2 and its in situ complexation with the Cd2+ cation were investigated by 1H-, 13C-, 113Cd-NMR and 1H,15N z-GS HMBC spectroscopy. The results support the formation of a highly symmetrical helical 6-coordinate podate [CdL2](NO3)2 (2). The structure of 2 has also been verified by ab initio HF-MO calculations using a standard 3-21G* basis set (Lan2DZ for Cd).

Crystal Structure of N,N-Dimethylthioformamide Solvates of the Divalent Group 12 Ions with Linear Coordination Geometry for Mercury(II), Tetrahedral for Zinc(II), and Octahedral for Cadmium(II).

The crystalline solvates of the divalent group 12 metal ions with the soft sulfur donor N,N-dimethylthioformamide display an unusual variation in coordination number and geometry with two, four, and six ligands attached to the mercury(II), zinc(II), and cadmium(II), ions, respectively. Bis(N,N-dimethylthioformamide)mercury(II) perchlorate precipitates from acetonitrile solution when adding less than 2 equiv of N,N-dimethylthioformamide, while the zinc and cadmium solvates crystallize from saturated N,N-dimethylthioformamide solutions. The disolvate [Hg(SCHN(CH(3))(2))(2)](ClO(4))(2) crystallizes in the monoclinic space group P2(1)/n (No. 14) with a = 6.208(1) Å, b = 15.239(7) Å, c = 8.681(2) Å, beta = 99.30(3) degrees, and Z = 2. Centrosymmetric mercury(II) complexes with strong collinear bonds to two N,N-dimethylthioformamide molecules, Hg-S 2.350(2) Å, are joined by double bridges of perchlorate ions in chains along the a-axis by four weak interactions between the mercury and the perchlorate oxygen atoms, mean Hg-O distance 2.84 Å. Tetrakis(N,N-dimethylthioformamide)zinc trifluoromethanesulfonate, [Zn(SCHN(CH(3))(2))(4)](CF(3)SO(3))(2), crystallizes in the triclinic space group P&onemacr; (No. 2) with a = 10.487(3) Å, b = 12.910(3) Å, c = 13.489(5) Å, alpha = 68.800(4) degrees, beta = 69.260(4) degrees, gamma = 74.06(1) degrees, and Z = 2, with the zinc ions tetrahedrally surrounded by four N,N-dimethylthioformamide ligands, mean Zn-S distance 2.34 Å. Also the cadmium solvate of corresponding composition, [Cd(SCHN(CH(3))(2))(4)(CF(3)SO(3))(2)], crystallizes in the space group P&onemacr;, with a = 8.670(1) Å, b = 9.529(1) Å, c = 10.685(1) Å, alpha = 75.20(1) degrees, beta = 66.97(1) degrees, gamma = 65.31(1) degrees, and Z = 1, although the structure comprises centrosymmetric tetrakis(N,N-dimethylthioformamide)bis(trifluoromethanesulfonato)cadmium(II) complexes in which four Cd-S bonds (mean 2.65 Å) and two weaker Cd-O bonds at 2.470(2) Å to the trifluoromethanesulfonate ions give rise to a pseudo-octahedral coordination around the cadmium ion. When using perchlorate instead as counterion, hexakis(N,N-dimethylthioformamide)cadmium perchlorate, [Cd(SCHN(CH(3))(2))(6)](ClO(4))(2), crystallizes in the space group P2(1)/n with a = 12.757(1) Å, b = 7.4681(6) Å, c = 19.732(2) Å, beta = 96.31(1) degrees, and Z = 2. The mean Cd-S bond distance increases to 2.715 Å in the fully solvated cadmium ion with almost regular octahedral coordination geometry to its six centrosymmetrically related ligands. The effect of the weak internal hydrogen bonding occuring between the hydrogen atom of a -CHS group and the sulfur atom of neighboring N,N-dimethylthioformamide ligands is discussed.

Size Quantization in Electrodeposited CdTe Nanocrystalline Films

We describe the deposition and characterization of nanocrystalline CdTe films which exhibit size quantization. The CdTe films were electrodeposited from a dimethylsulfoxide solution of tri-(n-butyl)phosphine telluride and cadmium perchlorate at 100 °C. The stoichiometry of the films depends on applied potential and solution composition. The films contained about 5−10% Te excess and exhibited small blue shifts (0.1−0.2 eV) in their optical spectra. XRD and electron microscopy indicated a typical crystal size of ca. 8 nm. Pulse reverse plating was used to improve the film stoichiometry. The nanocrystal size could be controlled by the pulse parameters, and almost stoichiometric films with average crystal sizes from 4 to 7 nm were obtained, showing increases in bandgap up to 0.8 eV. Annealing the films resulted in gradual crystal growth and corresponding spectral red shifts until the bulk bandgap was reached. X-ray photoelectron spectroscopy (XPS) showed phosphorous incorporation in the films. The small cryst...

Spectroscopic and crystallographic characterisation of cadmium complexes incorporating a bidentate phosphine ligand

The 1∶1 stoichiometric addition of the bidentate phosphine ligand 2,2-dimethyl-2-sila-1,3-bis(diphenylphosphino)propane (L2) to a range of cadmium(II) salts produced a series of moisture-sensitive complexes of general formula [CdX2(L2)] (X = Cl 1, Br, I, SCN or NO3). These complexes have been investigated by vibrational and multinuclear (31P and 113Cd) NMR spectroscopy and by X-ray crystallography. Complex 1 crystallises in the orthorhombic space group P212121, with a = 9.2862(10), b = 15.386(2), c = 20.724(3) Å, U = 2960.9(6) Å3 and Z = 4. The metal centre exhibits four-co-ordinate, tetrahedral geometry, with the ligand bound in a bidentate manner. Both the solution- and solid-state cross-polarisation magic angle spinning 31P NMR spectra of the complexes show clearly resolved 113Cd–31P and 111Cd–31P one bond couplings in a 113Cd∶111Cd ratio of 1.044∶1.046 as expected. Vibrational spectroscopy indicates that each complex is mononuclear, with no evidence for bridging species; [Cd(NO3)2(L2)] features monodentate nitrate groups. The addition of 2 equivalents of the ligand to cadmium perchlorate yields a complex which has been established as [Cd(L2)2][ClO4]2 by spectroscopic and conductance studies.

The X-ray crystal structure of bis(dicyclohexyldithiophosphato)cadmium(II)

The compound bis(dicyclohexyldithiophosphato)cadmium(II), [Cd{S 2P (OCy) 2} 2], has been obtained by reacting cadmium(II) perchlorate with the sodium salt of dicyclohexyldithiophosphoric acid in ethanol. Its structure was solved by X-ray diffraction. The structure consists of dimers in which each metal centre is coordinated by a chelating ligand and two bridging ligands, giving a coordination number of 4. The two bridging ligands and the two cadmium atoms form an eight-membered ring with a twisted chair conformation.

Synthesis and Structure of the Zinc(II) and Cadmium(II) Complexes Produced in the Photoluminescent Enhancement of Ninhydrin Developed Fingerprints Using Group 12 Metal Salts

Abstract The complexation reactions involving Ruhemann's purple (RP) and either zinc(II) or cadmium(II), which are made use of in the enhancement of latent fingerprints that have undergone preliminary development with ninhydrin, have been investigated under a variety of conditions. Contrary to earlier reports it is now clear that metal complexes with either a 1:1 or 1:2 metal:ligand ratio can be formed under certain conditions. Polar solvents, which cause extensive ionization of the metal salt, facilitate the formation of the 1:2 complex whereas less polar solvents allow the formation of 1:1 complexes through retention of a covalently bound anion in the primary coordination sphere. Thus, Zn(RP)2 can be prepared from seemingly any zinc(II) salt and NaRP in water or methanol. It is a highly insoluble and kinetically stable red powder with fluorescence emission bands at 590 and 640 nm. The structure of an orange 1:1 Zn:RP complex, produced as crystals from ZnCl2 and NaRP in a 5:1 chloroform:methanol mixture, has been solved by X-ray diffraction and shown to correspond to a formula of NaZn2(RP)2Cl3CH3OH. This material is very rapidly decomposed into its components by water. The previously reported 1:1 Cd:RP complexes, which are red, form under a much wider range of conditions than their zinc(II) counterparts, however, if cadmium(II) perchlorate is combined with RP in water or methanol Cd(RP)2 precipitates instead. This is a golden-brown powder showing a strong fluorescence.

Synthesis, crystal structure and spectroscopic properties of bis(diphenyldithiophosphinato)cadmium(II)

Reacting cadmium(II) perchlorate with the ammonium salt of diphenyldithiophosphinic acid in ethanol yielded the title compound, which crystallized in the triclinic space group P 1 with a = 9.273(1), b = 10.426(1), c = 13.845(3) Å, α = 94.38(1), β = 103.16(1), γ = 104.63(1)° and Z = 2. The crystal contains dimeric complexes in which two cadmium atoms and two bridging ligands form an eight-membered ring, the coordination of each metallic centre being made up to four by an additional S,S-dentate chelating diphenyldithiophosphinate ligand. Solid state vibrational spectra (IR and Raman) and multinuclear NMR spectra in DMSO solution ( 13C, 31P and 113Cd) are discussed and compared with those of aliphatic cadmium(II) dithiophosphinates.

Cadmium(II) Perchlorate Complexes with Group VB Donor Ligands

Cadmium(II) Perchlorate Complexes with Group VB Donor Ligands

Synthesis and complexation studies of mesocyclic and macrocyclic polythioethers. 9. Crystal and molecular structure of (1,4,7,10,13-pentathiacyclopentadecane)cadmium(II) perchlorate hydrate: a seven-coordinate cadmium

Synthesis and complexation studies of mesocyclic and macrocyclic polythioethers. 9. Crystal and molecular structure of (1,4,7,10,13-pentathiacyclopentadecane)cadmium(II) perchlorate hydrate: a seven-coordinate cadmium

Cation Exchange Studies of Cadmium Chloride, Bromide and lodide Complexes in Aqueous Acetone Solution

The distribution equilibria between cadmium (II) chloride, bromide, iodide and perchlorate complexes and the cation exchange resin in aqueous acetone solutions have been investigated. Formation constants of cadmium halides or perchlorate have been calculated from the distribution coefficients of cadmium in aqueous acetone solutions containing 10, 20, 30 and 40 v/v% water. Cadmium concentrations of the solutions have been measured by the atomic absorption spectrophotomer equipped with a carbon tube atomizer. The logarithmic values of constants in 10 v/v% aqueous acetone are: β1Cl =6.25, β2Cl =11.05 and β3Cl =14.59 for cadmium chloride, β1Br=6.97 and β2Br=10.35 for cadmium bromide, β1I=7.02 and β2I=11.80 for cadmium iodide, β1ClO4=2.18 for cadmium perchlorate. Formation constants of cadmium chloride are lower than those of cadmium iodide because of soft basicity of cadmium.

Differences in nature and stability of cadmium complexes with Group 15/Group 16 donor ligands as determined by multinuclear (phosphorus-31, selenium-77, cadmium-113) magnetic resonance and electrochemical techniques

Multinuclear ({sup 31}P, {sup 77}Se, {sup 113}Cd) magnetic resonance and electrochemical studies have been carried out to investigate the nature and stability of cadmium complexes with Ph{sub 2}PCH{sub 2}P(E)Ph{sub 2} (E = S (dpmS), Se (dpmSe)) and Ph{sub 2}P(E)CH{sub 2}P(E)Ph{sub 2} (E = S (dpmS{sub 2}), Se (dpmSe{sub 2})) in dichloromethane solution. The NMR studies indicate a cadmium preference for selenium or sulfur rather than phosphorus coordination in the dpmE complexes but are limited in scope with the NMR technique to examination rather than phosphorus coordination in the dpmE complexes but are limited in scope with the NMR technique to examination of the 1:2 cadmium to ligand stoichiometry due to the labile nature of the systems in the presence of excess ligand. Cadmium-selenium coupling is observed in some cases. The electrochemical reductions of both (Cd(dpmE){sub 2}){sup 2+} and (Cd(dpmE{sub 2}){sub 2}){sup 2+} at a mercury electrode are reversible two-electron processes. Ligand coordination numbers of 4 and 6 are attained with the dpmE complexes, but the dpmE{sub 2} complexes have a maximum ligand coordination number of 4 even at very high ligand to metal concentration ratios. The magnitudes of the calculated stability constants suggest that all of the dpmE and dpmE{submore » 2} complexes of cadmium(II) are essentially nondissociated in solution. The use of a Cd(Hg) amalgam electrode allows examination of the voltammetry of these cadmium systems in the presence of substoichiometric ligand concentrations and reemphasizes the high stability of the dpmE and dpmE{sub 2} complexes. The preference of cadmium for the group 16 donor atoms rather than phosphorus in the dpmE complexes is confirmed by an investigation of the interactions of cadmium perchlorate with PPh{sub 3} and PPh{sub 3}Se and by suitable mixing experiments. 25 refs., 4 figs., 5 tabs.« less

An X-Ray Diffraction Study on the Structure of Solvated Cadmium(II) Ion and Tetrathiocyanatocadmate(II) Complex in N,N-Dimethylformamide

Abstract The structure of solvated cadmium(II) ion and the tetrathiocyanatocadmate(II) complex in N,N-dimethylformamide (DMF) has been determined by means of X-ray diffraction at 25 °C. The radial distribution curve for a cadmium(II) perchlorate DMF solution is well explained in terms of the presence of the octahedral [Cd(dmf)6]2+ complex with the Cd–O bond length of 229.6(4) pm, which is practically the same as that within [Cd(dmso)6]2+ in DMSO and [Cd(H2O)6]2+ in H2O. It is also found that the tetrathiocyanatocadmate(II) complex has a tetrahedral structure, [Cd(NCS)3(SCN)]2−, with three Cd–N and one Cd–S bonds, the distances being 223(2) and 257(2) pm, respectively. The coordination structure of the complex in DMF is different from that found in aqueous solution, [Cd(NCS)2(SCN)2]2−.

Multinuclear NMR studies of the divalent metal binding site of NADP-dependent isocitrate dehydrogenase from pig heart

The metal activator site of NADP-dependent isocitrate dehydrogenase from pig heart has been probed by using 113Cd and 25Mg NMR as well as manganese paramagnetic relaxation of nuclei in the fast-exchanging ligands alpha-ketoglutarate and adenosine 2'-monophosphate. Cadmium NMR shows that cadmium, bound to the enzyme in the presence of isocitrate, has a resonance at 9 ppm relative to cadmium perchlorate, while the free Cd-isocitrate complex has a resonance at -23 ppm. Comparison with model compounds and previously studied proteins indicates that cadmium is coordinated with six oxygen ligands. Measurements as a function of cadmium concentration give a dissociation constant of 66 microM and a dissociation rate constant of 1.5 X 10(4) s-1 at pH 7.0. 25Mg NMR demonstrates that the line width of the magnesium resonance is increased upon binding to isocitrate dehydrogenase. A further increase in line width is observed upon addition of isocitrate. Measurement of line widths as a function of temperature reveals that in the binary complex between magnesium and enzyme, exchange is the major contributor to broadening while in the ternary complex containing isocitrate, the intrinsic relaxation in the bound state is also important, suggesting an increase in the dissociation rate constant for magnesium from the ternary complex. Paramagnetic relaxation studies of nuclei of alpha-ketoglutarate, bicarbonate, and adenosine 2'-monophosphate locate the divalent metal within the active site. The results with adenosine 2'-monophosphate show that atoms in the adenosine moiety of the coenzyme are at least 8 A from the metal site.(ABSTRACT TRUNCATED AT 250 WORDS)

Thermochemical properties of cadmium perchlorate and its hydrates

1. The enthalpies of solution in water at 25°C have been measured and the standard enthalpies of formation determined for (in kJ/mole): Cd(ClO4) ΔHsoln=-114.0 ±0.7, ΔHf298° =-219.7 + 1.2, Cd(C104)2·2H2O ΔHsoln=-57.84 ±0.5, ΔHf298°=-847.5 ±1.2. 2. The enthalpies have been calculated for the successive hydration of cadmium perchlorate up to the dihydrate and the hexahydrate.

Electrodeposition of CdS using nonaqueous triphenylstibine sulfide

Using a room temperature solution of cadmium perchlorate and triphenylstibine sulfide in propylene carbonate, thin film n-CdS has been deposited on a variety of substrates. The resulting films require no annealing to be photoactive. Stoichiometry was confirmed by Rutherford backscattering analysis. The deposited CdS has a bandgap of 2.63 eV and exhibited good photoresponse in a photoelectrochemical cell. At elevated temperatures (above 80°C), the deposition proceeds electrolessly. Preliminary results using films deposited by a superimposed ac current on a dc current are also reported.

Structures of monomethylcarbonato- and hydrogencarbonato(1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane)cadmium(II) perchlorate, [Cd(O2COCH3)(Me4[14]aneN4)](ClO4) (I) and [Cd(O2COH)(Me4[14]aneN4)](ClO4) (II)

Structures of monomethylcarbonato- and hydrogencarbonato(1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane)cadmium(II) perchlorate, [Cd(O2COCH3)(Me4[14]aneN4)](ClO4) (I) and [Cd(O2COH)(Me4[14]aneN4)](ClO4) (II)