ChemInform Abstract: Ti2Ni2In,Zr2Co2In,and Zr2Pd2In - Intermetallic Compounds with Ordered U3Si2 and Zr3Al2 Type Structure.

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.     

Eu3+ und Eu2+ in Oxometallaten der Zusammensetzung MBeLn2O5: SrBeEu2O5 und EuBeNd2O5

Eu³⁺ and Eu²⁺ in Oxides of the Composition MBeLn₂O₅: SrBeEu₂O₅ and EuBeNd₂O₅ Single crystals of (I): SrBeEu₂O₅ and (II): EuBeNd₂O₅ were prepared by CO₂-LASER (I) in air and plasma torch (II) technique in H₂ atmosphere. X-ray investigations led to orthorhombic symmetry, space group D-Pnma; (I): a = 9.488, b = 7.156, c = 6.495 Å; (II): a = 9.534, b = 7.225, c = 6.544 Å, Z = 4. Sr²⁺ and Eu³⁺ as well as Eu²⁺ and Nd³⁺ are in statistical distribution within a Kagomé framework. Both compounds are discussed with respect to the monoclinic form of MBeLn₂O₅.     

Molecular and electronic structure of several heterofullerene BNC58 and B2N2C56 oligomers and [B2N2C56] n macromolecule

Molecular and electronic structure of heterofullerene BNC₅₈ (C _s) and B₂N₂C₅₆ (C _2h) monomers, B₂N₂C₁₁₆ and B₄N₄C₁₁₂ dimers, and B₆N₆C₁₆₈ trimer (the last three molecules withC _2h symmetry) was simulated by the MNDO method. Clusters BNC₅₈ and B₂N₂C₅₆ are formed by replacement of carbon atoms participating in one or two of the most distant oppositely lying (6,6)-type C−C bonds in fullerene C₆₀ by B and N atoms. In one of the two studied isomers of the B₂N₂C₁₁₆ dimer, the monomers are linked by the four-membered carbon cycle, while the heteroatoms form the most distant oppositely lying bonds of the dimer. In the other isomer of the B₂N₂C₁₁₆ dimer, as well as in the B₄N₄C₁₁₂ dimer and B₆N₆C₁₆₈ trimer, the monomers are linked by four-membered B₂N₂ cycles with alternation of the atoms. For all the systems studied, the optimum geometric parameters, heats of formation, ionization potentials, and atomic charges were calculated. Dimerization energies of heterofullerenes BNC₅₈ and B₂N₂C₅₆ lie in the range from 33 to 49 kcal mol⁻¹. It was found that the B₂N₂C₁₁₆ dimer, in which the monomers are linked by the four-mernbered carbon cycle, is the most stable system. In the case of B₂N₂C₅₆ trimerization, the energy gain (compared to the triple monomer energy) is about twice as large as the dimerization energy. Molecular structure of the quasi-linear [B₂N₂C₅₆) _n macromolecule was simulated, and extended Hückel calculations of its energy band structure by the crystal orbital method were performed. It was found that the electron energy spectrum is of semiconducting type (the band gap is equal to 1.27 eV. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 431–435, March, 1999.     

ChemInform Abstract: Isomers of P2S2.

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.     

ChemInform Abstract: Ab initio Effective Core Potential Calculations on HgI2, PtI2, and PbI2.

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.     

ChemInform Abstract: Investigation of Heterodimeric and Homodimeric Radical Cations of the Series: [F2O2]+, [F2Cl2]+, [Cl2O2]+, [F4]+, and [Cl4]+.

Structures, thermochemical stability, Born‐Fajans‐Haber cycles, and vibrational data of the title ions are quantum‐chemically obtained by coupled‐cluster calculations with single and double substitution as well as perturbative triple excitations.     

ChemInform Abstract: Bonding and Dynamics of the ThCr2Si2 and CaBe2Ge2 Type Main Group Solids: A Monte Carlo Simulation Study.

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.     

Zur Kenntnis eines Barium-Kupfer-Orthoarsenats: BaCu2(AsO4)2

On the Crystal Structure of Barium-Copper-Orthoarsenate BaCu₂(AsO₄)₂ Single crystals of BaCu₂(AsO₄)₂ were prepared above 1 000°C by CO₂-LASER technique and investigated by X-ray structure determination. The light blue crystals show monoclinic symmetry, space group C? P2₁/n, a = 4.752; b = 8.506; c = 8.945 Å; β = 93.49°, Z = 2. BaCu₂(AsO₄)₂ represents a hitherto unknown structure type with Cu²⁺ in trigonal bipyramidal coordination. Ba²⁺ shows an 8 + 2 surrounding by O^2? and As⁵⁺ is tetrahedrally coordinated. The crystal structure is discussed with respect to related orthophosphates and vanadates.     

ChemInform Abstract: Ab Initio Quantum Chemical Calculations on Uranyl UO2+ 2, Plutonyl PuO2+ 2, and Their Nitrates and Sulfates.

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.     

Losartan Interactions with 2-Hydroxypropyl-β-CD

Losartan potassium salt (LSR) is a well-known antihypertensive drug with proven beneficial effects on human health. Its formulation with the non-toxic 2-hydroxypropyl-β-cyclodextrin (2-HP-β-CD) could improve its pharmacological profile. Thus, its molecular interactions are studied using a combination of Differential Scanning Calorimetry (DSC), Nuclear Magnetic Resonance (NMR) and Molecular Dynamics (MD). First, its complexation is shown through Differential Scanning Calorimetry as lyophilization provided distinct thermal properties in comparison to the mixture. The complexation is further proved by utilizing the chemical shift changes in the complexation and T1 values. Furthermore, the reversible favorable complexation was shown by MD calculations. Such physical chemical properties provide evidence that this formulation must be further explored through biological experiments.     

ChemInform Abstract: Singlet Diradical Character of S2N2.

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.     

单层含氧缺陷δ-MnO2用于二氧化碳还原

电催化还原二氧化碳成多碳燃料一直是研究的热点. 而找到活性高,选择性优,稳定性好的催化剂一直是研究者们奋斗的目标. 二氧化锰因其独特的物理和化学性质被广泛的应用于电催化领域,而缺陷的调控可以改变催化剂的电子性质,在此次工作中作者系统地研究了在有氧缺陷和没有氧缺陷的二维二氧化锰上的电催化二氧化碳还原反应. 通过利用自旋极化密度泛函理论,作者分别计算了他们的电子性质和分子在吸附过程中的能量值. 结果显示,缺陷的引入改变了二氧化锰的特性,使其从半导体性质变为半金属性质,从而提高催化剂的导电性. 同时,分析能量图也很容易发现对应产品的选择性也发生了变化. 二氧化锰有利于甲酸的产生,而氧缺陷的二氧化锰更有利于一氧化碳的生成. 本研究将为二氧化碳还原的其他非贵金属氧化物催化剂的结构设计和优化提供一定的指导.     

RuH2和RuN2电子组态与光谱性质的从头计算

Using DFT method at B3LYP / 6-311G** level,the possible electronic states of RuH2 and RuN2 have been calculated,including the chemical adsorption and physical adsorption. For the RuH2 cluster,electronic states 3B2 and 5Σ- correspond to the physical adsorption. The RuN2 calculation results were also compared with the experimental values on ruthenium single crystal surfaces. It is found that the single states and the triplet states are in good agreement with the experimental values. For the C∞v symmetry,the calculated frequency of the quintuple state 5Σ- is slightly lower than the experimental value. For the C2v symmetry,the frequencies of the quintuple states are much lower than the experiment value and the 3B2 and 5A1 states are unstable.