Inhibition effect of azole derivate on corrosion activity of copper in rolling oil

Corrosion rates are influenced by the formation of inhibitor aggregates on the copper surface. Laser scanning confocal microscope was used to investigate the adsorbed structures of benzotriazole, N‐((6‐methyl‐1H‐benzo[d][1,2,3]triazol‐1‐yl)methyl)‐N‐octyloctan‐1‐amine (MBA) and 2,5‐bis (ethyldisulfanyl)‐1,3,4‐thiadiazole at copper surface in relation to their performance as a corrosion inhibitor. The increase of water contact angle in the presence of inhibitor indicates its strong adsorption to the copper, and laser scanning confocal microscope visualization confirms the formation of MBA aggregates. The aggregates change from hemispherical to cylindrical shape with MBA concentration increasing in rolling oil, resulting in a decrease in corrosion rates as determined by mass loss measurements. Compared with 2,5‐bis (ethyldisulfanyl)‐1,3,4‐thiadiazole, oil‐added MBA has a quicker adsorption and formation speed of cylindrical aggregates and a lower corrosion rate. The adsorption of inhibitors on copper surface obeys Langmuir isotherm and physisorption and chemisorption mechanism. Copyright © 2015 John Wiley & Sons, Ltd.     

初等函数的导数是初等函数吗

给出实例说明初等函数的导数可以是非初等函数.     

Antiviral drug nevirapine as a template for hydrated imidazoline ring expansion (HIRE): Rapid access to the diarene-fused 1,4,7-triazecine ring system

The tricyclic ring system of the antiviral drug nevirapine has been employed to test the workability of the hydrated imidazoline ring expansion (HIRE) reaction which was previously exemplified for [1.4]oxazepine and [1.4]thiazepine counterparts. The imidazoline nucleus was grafted onto the lactam moiety of nevirapine in two high-yielding steps. Subsequent N-alkylation and the HIRE reaction proceeded as envisioned and delivered rare ring-expanded diarene-fused 1,4,7-triazecines with a diversity of alkyl substituents at the lactam nitrogen atom. These findings extend the scope of the HIRE reaction to the medicinally prominent [1.4]diazepine chemical space.     

Trinuclear Metal Complexes Based on 1,10-Phenanthroline Derivates as Catalysts for Cleavage of a RNA-Model Substrate

Two multidentate ligands 2,9-di[6'-(2″-hydroxyl-3″-methoxyphenyl)-n-2',5'-diazahexyl]-1,10-phenanthroline(LA)and 2,9-di(6'-α-phenol-n-2',5'-diazahexyl)-1,10-phenanthroline(LB)were synthesized and fully characterized.Protonation of the ligands and the stability of the complexes of the ligands with divalent metal ions were investigated.The trinuclear metal complexes [Cu(Ⅱ)and Zn(Ⅱ)] of the ligands were studied,as catalysts,for the transphosphorylation of the RNA-model substrate 2-hydroxypropyl-p-nitrophenyl phosphate(HPNP).The second-order rate constants of HPNP-hydrolysis catalyzed by M3L and M3LH-1 were obtained,which indicated that Zn3LBH-1 was the most efficient catalyst among them.The proposed mechanisms included the activation of the substrate via binding to the metal ions and intramolecular nucleophilic attack by the deprotonated C2-hydroxyl of HPNP.     

1-(2-羟乙基)-2-烷基-咪唑啉缓蚀剂缓蚀机理的理论研究

采用量子化学计算、分子动力学模拟和分子力学相结合的方法, 对6种不同烷基链长的1-(2-羟乙基)-2-烷基-咪唑啉缓蚀剂抑制H2S腐蚀的缓蚀机理进行研究, 并对其缓蚀性能进行评价. 前线轨道分布和Fukui指数表明, 6种缓蚀剂分子的反应活性区域均集中在分子的咪唑环上, 3个反应活性中心分别位于咪唑环上的N(4), N(7)和C(8)原子, 可使咪唑环在金属表面形成多中心吸附. 分子的反应活性及活性区域分布对烷基链长并不敏感. 单分子吸附能、膜的内聚能、吸附角和链间距的计算数据显示, 缓蚀剂膜的稳定性以及膜与金属基体的结合强度随链长的增加而增大; 当正构烷基碳链长度大于13时, 缓蚀剂可在金属表面形成一层高覆盖度、致密的疏水膜, 能有效阻碍溶液中的腐蚀介质向金属表面扩散, 从而达到阻碍或延缓腐蚀的目的.     

2-取代芳基菲并咪唑类化合物的电子结构和光谱性质的理论研究

运用密度泛函理论,在B3LYP/6-31G(d)水平上对菲并咪唑(PI)及其8种2-取代芳基衍生物的结构进行了全优化,探讨了取代基对分子结构、电离势(I_P)、电子亲和势(E_A)、电荷转移、前线分子轨道能量和电子吸收光谱等方面的影响.采用含时的度泛函理论(TD-DFT)计算了各分子的气相及液相的电子吸收光谱,计算结果与实验值十分接近.并用GaussSum2.1程序模拟吸收光谱和态密度(DOS)图,结果表明,芳基4′-位上取代基对菲并咪唑(PI)和苯环的骨架结构没有很大的扰动,但它们重新调整了菲并咪唑环和苯环中原子电荷分布,前线分子轨道(LUMO)-HOMO)能隙降低,导致8种取代的化合物的吸收波长均发生了红移.     

Synthesis and catalytic properties of 1‐alkyl‐2‐imidazolineruthenium(II) complexes

New [RuCl₂(imidazoline)(arene)] complexes have been prepared. The complexes were characterized by conventional spectroscopic methods and elemental analyses. Upon reaction with 1,1‐diphenylprop‐2‐ynol they generate catalyst precursors that can perform the cycloisomerization of diallyltosylamide into N‐tosyl‐α‐methylenepyrrolidine. Copyright © 2004 John Wiley & Sons, Ltd.     

4,4'-二[N-(芘-1-基亚烃基)胺芳基]-2,2'-双噻唑的合成

以硝基苯乙酮为原料,经α-溴代、缩合和还原3步反应制得4,4'-二氨芳基-2,2'-双噻唑(3a,3c,3e);3a,3c和3e分别与酰基芘经缩合反应合成了6个新型的希夫碱——4,4'-二[N-(芘-1-基亚烃基)胺芳基]-2,2'-双噻唑(5a~5f),其结构经1H NMR,FT-IR和元素分析表征。5a~5f的熔点均300℃。     

A Dendritic Amphiphile for Efficient Control of Biomimetic Calcium Phosphate Mineralization

The phase behavior of a dendritic amphiphile containing a Newkome‐type dendron as the hydrophilic moiety and a cholesterol unit as the hydrophobic segment is investigated at the air–liquid interface. The amphiphile forms stable monomolecular films at the air–liquid interface on different subphases. Furthermore, the mineralization of calcium phosphate beneath the monolayer at different calcium and phosphate concentrations versus mineralization time shows that at low calcium and phosphate concentrations needles form, whereas flakes and spheres dominate at higher concentrations. Energy‐dispersive X‐ray spectroscopy, X‐ray photoelectron spectroscopy, and electron diffraction confirm the formation of calcium phosphate. High‐resolution transmission electron microscopy and electron diffraction confirm the predominant formation of octacalcium phosphate and hydroxyapatite. The data also indicate that the final products form via a complex multistep reaction, including an association step, where nano‐needles aggregate into larger flake‐like objects.