Electronic tuning of Mg2Cu6Ga5. A route to crystalline approximant and quasicrystalline phases

Studies of Mg2Cu6Ga5 reveal that this compound contains incomplete Bergman clusters in its structure and shows a pseudogap and empty bonding states just above the Fermi energy according to band calculations. Under a rigid band assumption, such a compound may be tuned to approximant and quasicrystal phases in which the required number of electrons are attained. Here, we replace part of Mg in the isotypic Mg2Cu6Ga5 with Sc, and both 1/1 approximant and icosahedral quasicrystal phases are obtained after some fine-tuning. This method closely correlates the pseudogap and bonding with Hume-Rothery concepts, thus giving useful directions for future quasicrystal searches, especially when approximants are not known.     

Interpenetrating networks of three-dimensional Penrose tiles in CaAu3Ga, the structurally simplest cubic approximant of an icosahedral quasicrystal

Double-Friauf polyhedra (DFPs) which play important roles in quasicrystal (QC) models are the unique building blocks in the novel 1/0 AC, CaAu(3+Delta)Ga(1-Delta) (Delta approximately equal to 0-0.13) [Pa_3; a = 9.0875(3)-9.1107(5) A]. The packing of DFPs generates interpenetrating networks of condensed three-dimensional Penrose tiles, the geometry of which is close to that assumed for QCs.     

Mg35Cu24Ga53: a three-dimensional cubic network composed of interconnected Cu6Ga6 icosahedra, Mg-centered Ga16 icosioctahedra, and a magnesium lattice

Single-crystal X-ray structural determinations for the Mg(35.12(4))Cu24Ga(53.58(6)) and Mg(35.6(4))Cu24Ga(52.66(6)) refined compositions (Fdm, Z = 4) reveal empty (Cu,Ga)12 icosahedra and centered MgGa16 icosioctahedra that are interconnected at every vertex to a compact three-dimensional anion network. A small range of variable occupancy exists on one of three Ga and one of four Mg positions. The clusters are well-bonded and held in different sized cavities, in which they are also directly bonded to a Mg cation network. The two networks thus interpenetrate each other, and there are no spacers. The new phase is isostructural with K39In80, K17In41, and the electron-poorer Na35Cd24Ga56, all of which contain clathrate-II-type cation frameworks. Electron counting using the classic (MO-based) cluster assignments indicates that the refined structure is substantially ideal and closed-shell. The symmetry of the present structure does not suggest a ready conversion to an icosahedral quasicrystal or its approximants.     

ICP-AES法测定铝中铁、硅、铜、镓、镁、锌、锰和钛

用 50g L氢氧化钠溶液溶解铝样品 ,硝酸 (1 1 )酸化 ,以ICP AES测定其中铁、硅、铜、镓、镁、锌、锰和钛等 8种杂质元素。     

Design of energy band alignment at the Zn(1-x)Mg(x)O/Cu(In,Ga)Se2 interface for Cd-free Cu(In,Ga)Se2 solar cells

The electronic band structure at the Zn(1-x)Mg(x)O/Cu(In(0.7)Ga(0.3))Se(2) interface was investigated for its potential application in Cd-free Cu(In,Ga)Se(2) thin film solar cells. Zn(1-x)Mg(x)O thin films with various Mg contents were grown by atomic layer deposition on Cu(In(0.7)Ga(0.3))Se(2) absorbers, which were deposited by the co-evaporation of Cu, In, Ga, and Se elemental sources. The electron emissions from the valence band and core levels were measured by a depth profile technique using X-ray and ultraviolet photoelectron spectroscopy. The valence band maximum positions are around 3.17 eV for both Zn(0.9)Mg(0.1)O and Zn(0.8)Mg(0.2)O films, while the valence band maximum value for CIGS is 0.48 eV. As a result, the valence band offset value between the bulk Zn(1-x)Mg(x)O (x = 0.1 and x = 0.2) region and the bulk CIGS region was 2.69 eV. The valence band offset value at the Zn(1-x)Mg(x)O/CIGS interface was found to be 2.55 eV after considering a small band bending in the interface region. The bandgap energy of Zn(1-x)Mg(x)O films increased from 3.25 to 3.76 eV as the Mg content increased from 0% to 25%. The combination of the valence band offset values and the bandgap energy of Zn(1-x)Mg(x)O films results in the flat (0 eV) and cliff (-0.23 eV) conduction band alignments at the Zn(0.8)Mg(0.2)O/Cu(In(0.7)Ga(0.3))Se(2) and Zn(0.9)Mg(0.1)O/Cu(In(0.7)Ga(0.3))Se(2) interfaces, respectively. The experimental results suggest that the bandgap energy of Zn(1-x)Mg(x)O films is the main factor that determines the conduction band offset at the Zn(1-x)Mg(x)O/Cu(In(0.7)Ga(0.3))Se(2) interface. Based on these results, we conclude that a Zn(1-x)Mg(x)O film with a relatively high bandgap energy is necessary to create a suitable conduction band offset at the Zn(1-x)Mg(x)O/CIGS interface to obtain a robust heterojunction. Also, ALD Zn(1-x)Mg(x)O films can be considered as a promising alternative buffer material to replace the toxic CdS for environmental safety.     

2, 3, 4, 5, 6-五苯基苯甲醛的新合成途径

从四苯基环戊二烯酮与乙二醇缩肉桂醛通过干法在260-270℃直接加成并脱CO,接着经氧化、水解制备了2,3,4,5,6-五苯基苯甲醛,对目标产物的结构进行了^1HNMR,IR,UV-Vis和元素分析表征。在对反应中间产物进行分离、鉴定的基础上提出了该反应的可能途径。     

A controllable synthetic route to Cu,Cu2O,and CuO nanotubes and nanorods

Reducing Cu(OH)4(2-) with hydrazine hydrate and glucose in the presence of a structure-directing surfactant at room temperature gave Cu and Cu2O nanotubes/nanorods, respectively, whereas facile hydrothermal treatment of Cu(OH)4(2-) precursor resulted in CuO nanotubes/nanorods.     

A new synthetic route to metal trithiophosphonates: syntheses and structures of [(C6H11)PS3Li2).THF.TMEDA]2 and [(C6H11))PS3Mg.2THF]2

A new synthesis for trithiophosphonates from primary phosphines, nBuLi (or nBu(2)Mg) and elemental sulfur is presented and its mechanism investigated; the lithium and magnesium salts of cyclohexyltrithiophosphonate have been fully characterised to reveal dimers in the solid state in which all three of the trithiophosphonate sulfurs are involved in metal bonding.     

New layered compounds with honeycomb ordering: Li3Ni2BiO6, Li3NiM'BiO6 (M' = Mg, Cu, Zn), and the delafossite Ag3Ni2BiO6

The new layered compound Li(3)Ni(2)BiO(6) has been prepared by a solid-state reaction. It crystallizes in the monoclinic C2/m space group; its lamellar structure is characterized by a honeycomb ordering between Ni(2+) and Bi(5+) within the slabs, while Li(+) ions occupy octahedral sites in the interslab space. Stacking defects weakly alter the XRD pattern. By substitution of half of the nickel ions, the new phases Li(3)NiM'BiO(6) (M' = Mg, Cu, Zn) isostructural with Li(3)Ni(2)BiO(6) have been synthesized under similar conditions. All these compounds demonstrate paramagnetic behavior at high temperature, and Li(3)Ni(2)BiO(6) exhibits an antiferromagnetic ordering at 5.5 K. By topotactic molten salt ionic exchange, the new delafossite compound Ag(3)Ni(2)BiO(6) has been also obtained and characterized.     

高能密度材料H2N5MN5H2 (M=Be,Mg,Ca,Zn,和Cd)的密度泛函理论研究

借助密度泛函理论,用B3LYP和BP86方法,对一系列潜在的新型高能密度材料分子H2N5MN5H2(M=Be,Mg,Ca,Zn,和Cd)进行了理论预测研究.结果表明,这些材料分子都非常稳定,不容易分解,其中H2N5BeN5H2最稳定.金属离子的配位作用对化合物的稳定起了重要作用.配体H2N5也因从金属M获得一个电子变成H2N5-离子而变得更稳定.     

营养不良婴幼儿红细胞内外锌、铜、钙、镁变化及其意义

对１８例营养不良婴幼儿血浆及红细胞内的锌,铜,钙,镁元素含量进行了测定,并与１５例健康婴幼儿进行对照。结果表明,营养不良患儿血浆中锌,钙降低,与健康组相比有显著性差异（Ｐ〈０．０１）;营养不良患儿红细胞内锌,镁降低,钙升高,与健康组相比均有显著性差异（Ｐ〈０．０１）。因此,营养不良婴幼儿红细胞内外锌,钙,镁的变化应引起重视。     

Mineral formation from aqueous solution. Part III. The stability of aurichalcite, (Zn,Cu)5(CO3)2(OH)6, and rosasite (Cu,Zn)2(CO3)(OH)2

Summary The stabilities of rosasite, (Cu, Zn)₂ (CO₃)(OH)₂, and aurichalcite, (Zn, Cu)₅(CO₃)₂(OH)₆, have been determined by solution experiments with computer calculations of aqueous species in equilibrium with the solid phases. G _f ^o values for rosasite and aurichalcite have been calculated as –1100 and –2766 kJ mol^–1 respectively for specific samples of the two minerals. Most of the difference between the free energies of the compounds and those of malachite, Cu₂(CO₃)(OH)₂, and hydrozincite, Zn₅(CO₃)₂(OH)₆ arises from substitution of the minor cation in the crystal lattice. Malachite, zincian malachite and rosasite should be considered as a single isomorphous series.Part II: A. K. Alwan and P. A. Williams,Transition Acct. Chem., 4, 319 (1979).     

Polymorphism of the bivalent metal vanadates MeV2O6 (Me = Mg,Ca, Mn,Co, Ni,Cu, Zn,Cd)

Based on the literature data, our former findings and additional DTA and high-temperature X-ray studies performed for CdV₂O₆, MgV₂O₆, and MnV₂O₆, a consistent scheme of the phase transformations of the MeV₂O₆ (Me = Mg, Ca, Mn, Co, Ni, Cu, Zn, Cd) metavanadates is constructed at normal pressure between room temperature and melting points. Three types of structures exist for the considered compounds: brannerite type (B), pseudobrannerite type (P), and NiV₂O₆ type (N). The following phase transformations have been observed: Me = Mg, B → P at 535°C; Me = Mn, B → P at 540°C; Me = Co, N → B at 660°C; Me = Cu, B (with triclinic distortion) → B at 625°C (secondary order); and Me = Cd, B → P at 170°. CaV₂O₆P, NiV₂O₆N, and ZnV₂O₆B exist in unique form in the entire temperature range. P-form seems to be favored by Me of larger ionic radii. N-form seems to appear at a peculiar d-shell structure and small Me size. Preliminary explanation of the dependence of the structure type on Me size is offered. New X-ray data are given for CdV₂O₆B, CdV₂O₆P, MgV₂O₆B, MgV₂O₆P, and MnV₂O₆P.     

五种中草药中七种元素含量测定研究

用火焰原子吸收法对五种中草药中K，Ca,Mg,Cu,Zn,Fe,Mn进行了测定，结果表明，这些元素与中药的药理作用有相关性。     

ChemInform Abstract: Na14K6Tl18M (M: Mg,Zn, Cd,Hg) and Na13.5Sm0.5K6Tl18Na: Novel Phases of Mg2Zn11-Type Structure with Octahedral and Centered Icosahedral Clusters.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.     

表面活性剂稀释火焰原子吸收法测定钙镁铜锌铁

用中性表面活性剂聚乙二醇辛基苯基醚稀释样品，火焰原子吸收法测定血清中钙、镁、铜、锌铁及尿样中钙、镁、消除了样品基体干扰，提高了钙、镁测定灵敏度，操作简便，并讨论了表面活性消除干扰的作用机理。     

Röntgenographische und schwingungsspektroskopische Untersuchungen an Spinell-Mischkristallen des Systems (Zn,Ga) Cr2Se4

X-ray and I. R. Spectroscopic Studies on Spinel Solid Solutions of the Zn_1–xGa_0.67xCr₂Se₄ System With the aim to get new compounds with spinel defect structure of the ß-In₂S₃ type, we studied the phase diagram of the Zn_1–xGa_0.67xCr₂Se₄ system. The spinel type solid solutions formed within x = 0—0.6 show a relatively large phase width with respect to the metal selenium ratio, i. e. the parameter z in the formula Zn_1–xGa_0.67(x+0.5z)Cr_2–z^IIICr_z^IISe₄. Ternary Ga_0.67Cr₂Se₄ does not exist, it decomposes to Cr₂Se₃ and Ga₂Se₃. Instead of the ß-In₂S₃ type, superstructure reflections of LiFeCr₄O₈ type are observed.     

Polycondensed heterocycles. II. A new preparative route to 11-Oxo-5H,11H-pyrrolo[2,1-c][1,4]benzothiazepine

6-Methylthio-10-oxo-5H,10H-pyrrolo[1,2-b]isoquinoline 11 was isolated in an attempted synthesis of 11-oxo-5H,11H-pyrrolo[2,1-c][1,4]benzothiazepine 1 from 1-(2-methylthiobenzyl)pyrrole-2-carboxylic acid chloride 9 , obtained using as starting material o-methylthiobenzyl bromide 3 and passing through 1-(2-methylthiobenzyl)pyrrole-2-carbonitrile 5 , by cyclization with aluminum chloride. However the successful demethylation with sodium in dimethylacetamide of 1-(2-methylthiobenzyl)pyrrole-2-carboxyamide 12 , formed by hydrolysis of nitrile 5 , allowed us to prepare by another way the corresponding thiol 13 and consequently the 1-(2-mercaptobenzyl)pyrrole-2-carboxylic acid 14 , which when subjected to intramolecular ring closure by CDI in place of DCC gave 1 in higher yield, 69% instead of 43%. Finally, the direct cyanation of 1-(2-ethoxycarbonylthiobenzyl)pyrrole 16 , prepared utilizing the 1-(2-mercaptobenzyl)pyrrole 15 obtained by demethylation of the corresponding thioanisol 4 which was carried out as above, afforded the unexpected 1-(2-ethylthio-benzyl)pyrrole-2-carbonitrile 17 .