Chronopotentiometric Analysis of Proteins at Charged Electrode Surfaces

Protein properties and functions are strongly dependent on the structure and amino acid content. In this work, catalytic hydrogen evolution reaction (CHER) of five proteins (human serum albumin, lysozyme, β‐synuclein, H2 A and H3 histones) were studied using constant current chronopotentiometric stripping (CPS) with the aim to find out the association between protein content and its electrochemical response. We have shown that the height and potential of CPS peak H in dependence on accumulation potential differed for the studied proteins, while the CPS peak area was almost the same for all of them. CV and CPS peaks H of Cys‐containing proteins appeared at less negative potentials in comparison to proteins without Cys, suggesting easier CHER. Acidic and basic proteins not containing Cys can be also recognized due to their different CPS response after their adsorption at the positive and negative charged interface.     

Studying Reaction Intermediates Formed at Graphenic Surfaces

We report in-situ production and detection of intermediates at graphenic surfaces, especially during alcohol oxidation. Alcohol oxidation to acid occurs on graphene oxide-coated paper surface, driven by an electrical potential, in a paper spray mass spectrometry experiment. As paper spray ionization is a fast process and the time scale matches with the reaction time scale, we were able to detect the intermediate, acetal. This is the first observation of acetal formed in surface oxidation. The process is not limited to alcohols and the reaction has been extended to aldehydes, amines, phosphenes, sugars, etc., where reaction products were detected instantaneously. By combining surface reactions with ambient ionization and mass spectrometry, we show that new insights into chemical reactions become feasible. We suggest that several other chemical transformations may be studied this way. This work opens up a new pathway for different industrially and energetically important reactions using different metal catalysts and modified substrate.

两体扰动势和H2O通道反应的三原子体系解析势

提出了两体扰动势的概念.通过两体扰动势构造多原子相互作用体系解析势的理论方法,获得了非线性三原子H2O相互作用体系的解析势函数.用势能面正确描述了O(1D)+H2→H2O→OH+H通道反应的性质.理论分析和实验结果非常符合.该方法比较容易推广构造多原子相互作用体系解析势.     

两体扰动势构造CO_2通道反应三原子体系解析势

应用两体扰动势，成功地构造了线性三原分子CO_2平衡态及通道反应的三原子 体系相互作用解析热。势函数不但定量地描述了CO_2平衡态的临界特性，而且势能 面正确的描述了O(~1D)+CO(X~1∑+)→CO_2→C(~3P)+O_2(X~3∑-_g)通道反应的性 质。理论分析与实验推测结果非常吻合。     

两体扰动势和H2O通道反应的三原子体系解析势

提出了两体扰动势的概念.通过两体扰动势构造多原子相互作用体系解析势的理论方法,获得了非线性三原子H2O相互作用体系的解析势函数.用势能面正确描述了O（1D）＋H2→H2O→OH＋H通道反应的性质.理论分析和实验结果非常符合.该方法比较容易推广构造多原子相互作用体系解析势.     

Detecting Reaction Pathways and Computing Reaction Rates in Condensed Phase

Methods for the computation of rate constants that characterize classical reactions occurring in the condensed phase are discussed. While microscopic expressions for these transport properties are well known, their computation presents challenges for simulation since reactive events often occur rarely, and the long time scales that are typical for reactive processes are not accessible using simple molecular dynamics methods. Furthermore, the underlying free energy surface is very complex with many saddle points that prevent sampling of possible reaction pathways. As a result, the reaction coordinate may be a complex many-body function of the system’s degrees of freedom. Since there is not an a priori way to define a “good” reaction coordinate, methods are being developed to assist in a systematic construction of a reaction coordinate. These methods are reviewed and examples of non-trivial reaction coordinates are presented.     

Phase and Order Behavior of Charged Asymmetric Diblock-Copolymer Melts in Bulk

The phase and order behavior of charged asymmetric diblock-copolymer melts is studied by using coarse-grained molecular dynamics simulation. One of the blocks is made charged and other one is kept neutral, and the study systematically explores how the charged diblock-coploymer responses as the charge fraction of the charged block is varied from 10% to 50%. When charge fraction increases, the study finds ordered transitions from interconnected cylinder-like structures to lamellae, then to gyroid structures. It is also found that domain size of the obtained equilibrium morphology decreases slightly with the increase in charge fraction of the charged block.     

不对称Henry反应的研究进展

总结了各种能有效催化不对称Henry反应的新方法、新条件和新催化剂,讨论了一类拓展的不对称催化Henry反应。对立体选择性催化Henry反应的催化剂的发展提出了作者的一些看法。参考文献26篇。     

不对称Baylis-Hillman反应研究进展

综述了光学活性的活化烯、亲电试剂、催化剂和溶剂对Baylis_Hillman反应的不对称诱导效果     

基于新一代密度泛函和神经网络势能面的量子反应动力学计算

介绍了近年来发展起来的新一代密度泛函XYG3及利用神经网络构造分子体系势能面的最新进展。以H₃和CH₅等体系为实例,表明基于高效准确的密度泛函电子结构计算,与神经网络高精度势能面构造的理想结合,可以得到可靠的化学动力学结果,并有望用于更大更复杂的体系。     

中等电位条件下的平板型双电层相互作用近似表达式

中等电位条件下的平板型双电层相互作用近似表达式王好平（抚顺石油学院材料科学与技术研究所，抚顺，１１３００１）金军（北京攀尼尔精细化工·贸易公司）关键词排斥能，平板胶粒，双电层，ＤＬＶＯ理论Ｌｅｖｉｎｅ［１］在研究单个球颗粒的非线性Ｐｏｉｓｓｏｎ－Ｂｏ...     

Exploring the Reaction Paths on the Potential Energy Surfaces of the S1 and T1 States in Methylenecyclopropane

The reaction paths of methylenecyclopropane 1 on the potential energy surfaces (PESs) of the lowest triplet (T₁) state and the lowest excited singlet (S₁) state, as well as that of the ground state (S₀), were explored by using the nudged elastic band method at the MRMP2//MCSCF/6‐31++G(d,p) and DFT(B3LYP)/6‐31++G(d,p) levels of theory. After vertical excitation of 1, three transition states on the PES of the lowest triplet state and one transition state on the S₁ PES were found along the reaction path to produce a carbene, cyclobutylidene 2. All of these transition states are lower in energy than the S₁ state produced by vertical excitation at the S₀ energy minimum in 1. Fast transition is predicted to occur from the T₁ state or from the S₁ state to the S₀ state due to strong spin‐orbit coupling or nonadiabatic coupling in the geometrical vicinity of 2. On the MRMP2 S₀ PES, the energy barriers of 5.0, 10.3 and 13.5 kcal mol^?1 were obtained for C migration reaction (backward reaction), 1,2‐H migration reaction to cyclobutene 3, and 1,3‐H migration reaction to bicyclopropane 4, respectively, started at 2. The introduction of phenyl groups makes the energy barriers smaller due to the π conjugation between the carbene center and phenyl groups.     

表界面分子吸附、组装与反应的电化学STM研究

电化学扫描隧道显微镜（electrochemical scanning tunneling microscopy：ECSTM）是用于化学以及表界面科学研究的重要新技术之一。它将电化学与STM技术相结合,能够工作于溶液和大气环境中,可以得到固体表面及表面吸附物质的原子／分子级分辨率的图像。本文简要介绍了电化学STM技术及其在表界面分子吸附、组装和反应研究中的应用。     

Interaction of CH4 with Electronically Excited O2: Ab Initio Potential Energy Surfaces and Reaction Kinetics

Plasma Chemistry and Plasma Processing - Multireference quantum chemical research with the aid of complete active space self-consistent field approach was performed to study the elementary...     

铜催化不对称烯丙基烷基化反应的研究进展

铜催化不对称烯丙基烷基化反应是一种重要的合成手性化合物的方法,综述了铜催化不对称烯丙基烷基化反应的最新研究进展,重点讨论了烯内基衍,生 物结构、手性配体结构及亲核试剂类型等因素对该类型反应的影响.     

不对称催化Pictet-Spengler反应研究进展

手性四氢-β-咔啉骨架广泛存在于天然产物和药物分子中, 是其活性的关键结构. 不对称Pictet-Spengler反应是高效构建四氢-β-咔啉化合物的直接途径. 根据有机催化剂种类, 我们从手性磷酸、 手性方酰胺和其他催化剂3个方面, 综述了近5年来有机催化不对称Pictet-Spengler反应的研究进展.