Sol-Gel Derived Silica Films with Ultrafine Copper, Copper Sulfide and Copper Selenide Particles

A development of the silica-based sol-gel materials in the form of films containing ultrafine copper compounds and metallic copper is presented. Semiconductor nanoparticles with new optical features due to size effects and unique chemical properties of copper are produced. The chemical state of copper-containing dopants was manipulated by the sequence of chemical transformations monitored with XRD and optical absorption spectroscopy and discussed together with other recent data (XPS, TEM). A number of nanocrystalline phases of sulfides and selenides controllable by preparation conditions were detected in the films. The chemical composition of the dopants controls optical absorption both in the visible and near IR ranges.     

Single-Source Molecular Precursor for Synthesis of Copper Sulfide Nanostructures

As a new precursor, [bis(thiosemicarbazide)copper(II)]chloride; ([Cu(TSC)₂]Cl₂), complex was used in thermal decomposition process for the synthesis of Cu₂S nanocrystals. The steric hindrance of the precursor raises the need of using co-surfactant, therefore oleylamine (C₁₈H₃₇N) and triphenylphosphine (C₁₈H₁₅P) were applied as solvent and surfactant of the reaction. CuS nanocrystals were synthesized via hydrothermal decomposition of [bis(thiosemicarbazide) copper(II)] without any surfactant. The products were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and photoluminescence spectroscopy. Synthesized copper sulfide nanostructures have average size of 20–50?nm. Finally, optical properties of the products were examined and investigated by PL spectra.     

Determination of Stability Constants of Copper(I) Chelates with 1,10-Phenanthroline by Thermal Lensing

Using investigations of the copper(I)–1,10-phenanthroline system as an example, it is shown that thermal lensing can be used for determining stability constants at a level of concentrations one–two orders of magnitude lower compared to conventional spectrophotometry, with better precision of measurements. The values of stability constants are log₂= 11.7 ± 0.7 without regard for stepwise chelation, and logK ₁= 5.9 ± 0.3, logK ₂= 5.4 ± 0.3, and log₂= 11.3 ± 0.6 taking into account stepwise chelation. It is shown that, when shifting from microgram to nanogram amounts of reactants in the determination of stability constants by thermal lensing, changes in the kinetic parameters of the reaction studied should be taken into account. The thermal-lens limit of detection of copper(I) is 2 × 10^–8M; the linear calibration range is 4 × 10^–8–2 × 10^–5M (488.0 nm, pump power 120 mW). The data obtained were used for determining copper(I) in the hydrogen sulfide layer of the Baltic Sea.     

Thermal Decomposition of Copper(I) Thiocarbamide Chloride Hemihydrate

Two combinations of simultaneous thermoanalytical techniques (TG+DTA and TG+EGA) were used to study the thermal decomposition of the title compound in order to gain a better insight into the spray pyrolytic processes leading to Cu2-xS and CuInS2 thin films. After dehydration a complex sequence of reactions starts above 220°C leading through several intermediates to the formation of CuO in air at 1000°C. In an inert atmosphere Cu2S is formed which in helium above 800°C partly decomposes to Cu. XRD and FTIR were used to identify the intermediate solid phases which in air included CuCl, Cu2OSO4, Cu2OCl2 and CuSO4. EGA-FTIR confirmed the complex reaction mechanism with NH3, HCl, H2O, COS, CO2 and some HCN as main gaseous products under oxidative conditions. This revised version was published online in July 2006 with corrections to the Cover Date.     

Mechanism of Passive Layer Formation during Electrochemical Oxidation of Copper(I) Sulfide

Russian Journal of Electrochemistry - The structure and phase composition of synthesized copper(I) sulfide are studied. It is shown that, both chalcocite (Cu2S) and jarleite (Cu31S16) phases can...     

铁铝复合柱撑粘土的制备、柱结构和稳定性(I)

用两种方法合成了一系列不同Fe/Al比的铁铝复合柱撑牯土(FeAl-PlLC). 用~(27)Al-NMR、UV、ESR等手段考察了柱溶液的结构和状态, 用XRD、DTA、UV-DRS 等技术对其结构、稳定性进行了研究. 结果表明, 铁铝柱撑粘土的底面间距为1.98～1.55 nm, Fe/Al比对其柱结构、比表面积、热稳定性均有较大影响. Fe/Al<0.5时, 层间柱主要呈现Keggin结构, Fe/Al≥0.5时, 可能为三聚结构. 随Fc/Al比的增加, d(001)值, 比表面面、热稳定性逐渐下降.     

三核铜(Ⅰ)配合物合成及结构分析

铜(I)配合物由于其变化奇异的结构,性质及配位数而引起化学工作者的广泛兴趣.众所周知,四电子供体双二苯基膦甲烷(dppm)适宜在近距离内与两个金属原子同时配位,容易形成八员环的二聚体M2P4C2[1],因而是桥联两个低氧化态过渡金属的最佳选择,由于在M2(dppm)2框架结构中的配位不饱和性,仍需有单齿或双齿配体参加配位,这也正是M2(dppm)2类配合物特殊的成键,反应性和催化性的主要原因,这种附加配体不仅影响金属离子的配位构型而且影响M2(dppm)2的框架结构,同时dppm能够稳定多核配合物.我们在配体dppm存在下直接还原铜(Ⅱ)盐得到双核铜(I)配合物[Cu(dppm)(NO3)]2[2],又在四苯基硼钠存在下部分取代弱配位的硝酸根制备了具有新奇结构的三核铜(I)配合物[Cu3(dppm)3(OH)(NO3)](NO3)CH3OH,通过元素分析,核磁,红外,电导等方法研究了配合物的有关物理化学性质,配合物的晶体和分子结构已由X-射线单晶结构分析确定.     

一维链状铜配位聚合物的合成、结构及热稳定性研究

A copper coordination polymer, {[Cu₃( μ-3-CPOA)₂( μ-3-PyO)₂(3-PyOH)₂(H₂O)₄]·4H₂O}_n (3-CPOA^2-=3-carboxylphenoxyacetate dianion, 3-PyOH=3-hydroxypyridine, 3-PyO^-=pyridin-3-onato) was synthesized and char-acterized by the element analysis, IR, TG and single crystal X-ray diffraction. The title complex crystallizes in triclinic system with space group P1, a=0.906 53(18) nm, b=1.155 9(2) nm, c=1.208 0(2) nm, α=93.25(3)°, β=111.05(3)°, γ=105.62(3)° and V=1.121 0(5) nm³, Z=1, R=0.052 6, wR=0.154 8. Each copper(Ⅱ) atom displays octahedron coordination geometry incorporating 3-carboxylphenoxyacetate and pyridin-3-onato ligands, except for the Cu1 atom also involving 3-hydroxypyridine and water molecules. Two adjacent copper(Ⅱ) atoms are bridged by the tridentate 3-CPOA^2- group and the tridentate pyridin-3-onato ligand, constructing a one-dimensional chain structure along b axis, with the adjacent Cu…Cu distances being 0.309 3(3) nm and 0.626 5(3) nm. CCDC: 287383.     

高硅沸石骨架结构及其稳定性的模拟计算(I)*

The lattice energy of a series of high-silica zeolites was determined using the lattice energy minimization method. The results were compared to the lattice energy of dense polymorphs of SiO2. All high-silica zeolites frameworks are only 30～67kJ•mol-1 less stable than α-quartz This may imply that there is little energy barrier to the formation of high-silica zeolites frame-works and explain the structural diversity observed for high-silica zeolites. The relationships of calculated lattice energies and framework Structures was disscussed. The results revealed a good linear relationship between framework density of these molecular sieves and all-silica framework lattice energies.     

Investigation of the Thermal Properties of a Series of Copper Selenide Cluster Molecules

The thermal properties of a series of the six copper selenide cluster molecules [Cu₂₆Se₁₃(PEt₂R)₁₄] (R = Ph, Et), [Cu₄₄Se₂₂(PEt₂Ph)₁₈], [Cu₇₀Se₃₅(PEt₂R)₂₃] (R = Ph, Et) and [Cu₁₄₀Se₇₀(PEt₃)₃₄] have been investigated along with a characterization of their thermolysis products. For all cluster molecules the phosphine ligand shells are cleaved at temperatures between 60°C and 200°C depending on the experimental conditions (Helium gas flow or vacuum), the type of phosphine ligand and the size of the cluster molecules. The residues of the thermal treatment to 150°C were found to be nanostructured Cu₂Se with crystallite sizes of approximately 12–16 nm which means that the 1–2.5 nm sized cluster cores of the precursor cluster molecules simultaneously grow during this process. A mixture of processes and factors including the strength of the Cu–P bond, the boiling point of the phosphine ligand as well as the thermal stability of the copper selenide clusters against formation of the bulk material determine the shape of the TGA curves. We found some indications in the TGA along with differential scanning calorimetry (DSC), which suggest that the cleavage of the phosphine ligands is probably mostly determined by the tendency of the metastable clusters to form the bulk material meaning their thermodynamic stability and not by the strength of the Cu–P bond. The data for the series of PEt₃ ligated clusters reveal that this stability is dependent on the size of the cluster molecules. Dedicated to Prof. G. Schmid on the occasion of his 70th birthday.     

Evolutionary Algorithm-Based Crystal Structure Prediction for Copper(I) Fluoride

Despite numerous experimental studies since 1824, the binary copper(I) fluoride remains unknown. A crystal structure prediction has been carried out for CuF using the USPEX evolutionary algorithm and a dispersion-corrected hybrid density functional method. In total about 5000 hypothetical structures were investigated. The energetics of the predicted structures were also counter-checked with local second-order Møller–Plesset perturbation theory. Herein 39 new hypothetical copper(I) fluoride structures are reported that are lower in energy compared to the previously predicted cinnabar-type structure. Cuprophilic Cu−Cu interactions are present in all the low-energy structures, leading to ordered Cu substructures such as helical or zig-zag-type Cu−Cu motifs. The lowest-energy structure adopts a trigonal crystal structure with space group P3₁21. From an electronic point of view, the predicted CuF modification is a semiconductor with an indirect band gap of 2.3 eV.     

Structure, Stability, and Lability of Copper(II) Complexes with Triglycine

Equilibrium constants of complex formation, rate constants of chemical exchange reactions, and characteristics of electronic absorption spectra for species detected in aqueous solution of copper(II) with triglycine were determined, and conclusions on the structure of the complexes were made. A possibility of H-bond formation between the ammonium group of the zwitter-ionic form of the ligand and the second peptide oxygen in the anionic form of an adjacent ligand was shown. Kinetics and mechanisms of ligand and proton exchanges in solutions of copper(II) bistripeptide complexes with the ligand containing a deprotonated peptide nitrogen atom were studied. A new mechanism was proposed for hydroxide-catalyzed substitution reactions in copper(II) complexes with tripeptides.     

Synthesis and Structure of the Copper(I) Complex Containing Bis(diphenylphosphino)ethane

1 INTRODUCTION Procedures to synthesize copper(I) complexes are of great interest because of the diversity of products resulting from almost the same methodology. It has long been known that four-electron-donor diphosphine compounds Ph2P(CH2)nPPh2 are excellent bidentate ligands[1]. The chelating tendency decreases as the chain length increases, so that for the ligands Ph2P(CH2)nPPh2, the tendency to chelation is the greatest for bis(diphenylphosphino)ethane. Copper(I) displays wide…     

Structure and Thermal Stability of Bi(III) Oxy-Clusters in Aqueous Solutions

The structure of Bi(III) clusters in aqueous concentrated acidic perchlorate solutions has been studied by means of X-ray absorption spectroscopy (XAS). The XAS data show that the polynuclear [Bi₆O₄(OH)₄]⁶⁺ complex with a cage structure predominates at room temperature in acidic Bi-rich solutions. This complex breaks down to form mononuclear complexes with increasing temperature to 428 K. This behavior is consistent with theoretical predictions based on considerations of the electrostatic repulsion, which increases sharply as the dielectric constant of the solvent decreases with increasing temperature.     

双核铜(Ⅰ)配合物的合成、晶体结构与性质研究

本文合成了1个新的铜双核配合物[(CuI)(PMN)]2.2CH3CN(PMN=2、4-二氨基-5-氯苯基-6-乙基嘧啶),并且通过元素分析、红外、荧光、热重和单晶X-射线进行了表征。该配合物属三斜晶系,空间群P1,a=0.8100(16)nm,b=0.96950(19)nm,c=1.2049(2)nm,α=97.88(3)°,β=93.31(3)°,γ=94.14(3)°,V=0.933 8(3)nm3,Z=1,R=0.037 1。在配合物中,每个Cu(Ⅰ)离子与PMN配体的1个N原子和2个I原子配位,展示出三角几何构型。相邻的2个Cu(Ⅰ)离子通过碘原子相连形成双核铜配合物,并进一步通过氢键和I…I作用形成三维网状结构。     

利用还原取代反应合成双核铜(Ⅰ)配合物及其晶体结构研究

铜(Ⅰ)配合物由于其变化奇异的结构、性质及配位数而引起化学工作者的广泛兴趣.四电子供体双二苯基膦甲烷(dppm)适宜在近距离内与2个金属原子同时配位,容易形成八元环的二聚体M₂P₄C₂,因而是桥联2个低氧化态过渡金属的最佳选择.     

Cu2I2(PPh3)3.DMF的合成和晶体结构

Ｃｕ２Ｉ２（ＰＰｈ３）３·ＭＤＦ（Ｐｈ＝Ｃ６Ｈ５,ＤＭＦ＝ＨＣＯＮ（ＣＨ３）２是通过Ｗ２Ｓ４（Ｓ２ＣＮ－（ＣＨ２ＣＨ２ＯＨ）２）２,ＰＰｈ３和ＣｕＩ在ＣＨ２Ｃｌ２和ＤＭＦ为溶剂,在室温条件下合成的晶体产物。其窨群为Ｐ２１／Ｃ,晶胞参数：Ｃ５７Ｈ５２Ｃｕ２Ｉ２ＮＯＰ３,α＝１５．８６３（５）,ｂ＝１９．６１９（７）,ｃ＝１８．２３２（４）,Ａ,β＝１０９．５３（２）°,Ｖ＝５３４８（３）Ａ＾３,Ｚ＝     

二（1N-苄基-苯并咪唑）二氯合钴配合物的晶体结构、电化学和热稳定性能研究(英)

0IntroductionBenzimidazoleisaninterestingheterocyclicringbecauseitispresentinvariousnaturallyoccurringdrugs,suchasomeprazole,astemizoleandemedastinedifumarate[1].Theefficacyofsubstitutedbenzimida鄄zolesinthetreatmentofparasiticinfectionsiswellknown[2,3].B…