Notes on Interpolation. X (Two Boundary Value Problems)

In this paper we use (0, 2) interpolational polynomials to give an approximate solution of the differential equation y(x) + A(x)y(x) = F(x), x I := [-1, 1] j in case when the boundary values are y(-1) = and y(1) = , , R.     

Activation mechanism of the human histamine H4 receptor--an explicit membrane molecular dynamics simulation study

Molecular dynamics (MD) simulations in a membrane-embedded environment were carried out on the homology model of the human histamine H4 receptor (hH4R) alone and in complex with its endogenous activator histamine and with the first reported selective hH4R antagonist JNJ7777120. During the simulation of the histamine-hH4R complex, considerable changes occurred in the hH4R structure as well as in the interaction pattern of histamine at the binding site. These changes are in agreement with experimental data published on GPCR activation. In particular, the intracellular side of TM helix VI moved significantly away from TM helices III and VII. Moreover, histamine formed an interaction with Asn147 (4.57) that was previously proved to be important in hH4R activation. Results of the MD simulations of the native hH4R and the JNJ7777120-hH4R complex suggest that these models represent an inactive conformation of hH4R. MD simulation in the presence of JNJ7777120 resulted in the movement of the intracellular side of TM helix VI in the direction of TM helix III. Snapshots of the simulations may serve as functionally relevant models in the development of novel hH4R ligands in the future.     

A DFT study on the vibrational spectroscopy of protoporphyrin IX

Infrared and Raman spectra of protoporphyrin IX were recorded. DFT quantum chemical calculations were performed. Optimised molecular geometry, electric charge distribution, vibrational force constants were computed. The normal coordinate analysis and the scaling of the force constants yielded all the necessary data for the simulation of the infrared and Raman spectra and the potential energy distribution calculations. The result was the interpretation of all vibrational modes of the molecule. Conclusions were drawn from the difficulties arisen during the assignment of the vibrational spectra of such large molecules.     

Anionic Chains of Parent Pnictogenylboranes

We report on the synthesis and structural characterization of unprecedented anionic parent compounds of mixed Group 13/15 elements. The reactions of the pnictogenylboranes H₂E‐BH₂?NMe₃ ( 1 a =P, 1 b =As) with phosphorus and arsenic centered nucleophiles of the type [EH₂]^? (E=P, As) lead to the formation of compounds of the type [H₂E‐BH₂‐E′H₂]^? ( 2 : E=E′=P; 3 : E=E′=As; 4 : E=P, E′=As) containing anionic pnictogen–boron chain‐like units. Furthermore, a longer 5‐membered chain species [H₂As‐BH₂‐PH₂‐BH₂‐AsH₂]^? ( 5 ) and a cyclic compound [NHC^dipp‐H₂B‐PH₂‐BH₂‐NHC^dipp]⁺[P₅B₅H₁₉]^? ( 6 ) containing a n‐butylcyclohexane‐like anion were obtained. All the compounds have been characterized by X‐ray structure analysis, multinuclear NMR spectroscopy, IR spectroscopy, and mass spectrometry. DFT calculations elucidate their high thermodynamic stability, the charge distribution, and give insight into the reaction pathway.     

RIXS in correlated electron systems under extreme conditions

ABSTRACT

We report here on the application of Resonant Inelastic X-ray Scattering (RIXS) in correlated electrons systems under pressure. Thanks to its bulk sensitivity and superior resolving power, RIXS appears as a powerful spectroscopic technique to unravel the local electronic and magnetic properties of materials at extreme conditions. The method is illustrated in vanadium-oxides- and Fe-based superconductors at high pressure.     

Progress in Polyarsolyl Chemistry

The synthesis of heteroatom analogues of the cyclopentadienyl anion Cp^? is a fascinating and challenging field of research. The replacement of methine moieties by phosphorus is well investigated for the synthesis of mono‐, tri‐ and pentaphospholyl ligands. On the other hand, arsenic derivatives are rare and 1,2,4‐triarsolyl and tetraarsolyl salts are unknown. Herein, we report on the synthesis of Cs[E₃C₂(trip)₂] ( 1 a : E=P; 1 b : E=As; trip=2,4,6‐triisopropylphenyl) and Cs[E₄C(trip)] ( 2 a : E=P; 2 b : E=As). Compound 1 b represents the first 1,2,4‐triarsolyl and 2 b the first tetraarsolyl anion. All salts are obtained in one‐pot syntheses using E(SiMe₃)₃, 2,4,6‐triisopropylbenzoyl chloride and CsF. The products 1 a ?2 C₄H₈O₂, 2 a ?Et₂O and 2 b ?3 C₄H₈O₂ were characterized by X‐ray structural analysis, which revealed planar heterocycles. Nucleus‐independent chemical shifts (NICS) confirmed the aromaticity of these anions. Notably, compound 2 a ?Et₂O is only the second tetraphospholyl ligand which is structurally characterized.     

纳米多孔二氧化钛电极辅助光电化学降解乙酰氨基酚及伐昔洛韦

作为一类具有较高生物活性的物质,药物及个人护理品对环境的污染引起人们越来越多的关注.对乙酰氨基酚和伐昔洛韦是两种使用广泛的药物,由于其潜在的对人类健康和生态安全的威胁而逐渐成为研究热点.而电化学辅助光氧化技术因其具备能够高效处理难降解化学品的优点而得到广泛使用.本文合成了纳米多孔二氧化钛电极,研究了电化学还原处理对纳米多孔二氧化钛电极辅助光电化学降解对乙酰氨基酚和伐昔洛韦的影响.使用扫描电镜和色散谱技术对合成的纳米多孔二氧化钛电极的形态和元素组成进行了表征.循环伏安法、莫特-肖特基曲线、紫外-可见分光光度计和总有机碳分析仪被用来研究对乙酰氨基酚和伐昔洛韦的光电化学降解过程.结果显示,对乙酰氨基酚和伐昔洛韦的光化学降解和电化学降解过程非常缓慢,在研究的时间范围内其浓度未见明显变化,因此可以忽略不计.但是对乙酰氨基酚和伐昔洛韦的光电化学降解速度比较快,与未经处理的纳米多孔二氧化钛电极相比,经过电化学还原处理的电极可以使对乙酰氨基酚和伐昔洛韦的光电化学降解分别提高86.96%和53.12%.这可能是由于在电化学还原处理过程中生成了Ti3+, Ti2+和氧空位以及导电性的提高.还研究了温度对对乙酰氨基酚和伐昔洛韦光电化学降解的影响,随着温度升高,对乙酰氨基酚和伐昔洛韦的光电化学降解速率增大.