A New Metric for Evaluating DFT Calculated Proton and Carbon Chemical Shifts of Natural Products and Organic Compounds

The calculation of DFT (density functional theory) chemical shifts have become an important technique for the verification of a proposed structure. An easily calculated metric developed for proton and carbon chemical shifts of natural products and organic compounds, the calculated chemical shift index (CCSI), has been developed, which uses the deviation of each pair of calculated and experimental chemical shifts. The mean absolute deviation (MAD), which is commonly used as the goodness of fit metric for DFT calculated chemical shifts, can conceal large deviations in the calculated data. A classification strategy is also proposed for the CCSI to highlight when further assessment of the NMR data is required.     

Transport and Fate of Organic Compounds in the Global Environment

The role of chemistry in our soon-to-be global industrial society requires a global perspective for the discussion of the uptake, transport, and conversion of chemical compounds in the environment. The fate of organic compounds in the volume flow of the atmosphere and hydrosphere can be categorized into transport pathways and adjustments of equilibria in the multiphase system atmosphere-oceans-land surface. The global volume flow in the atmosphere (wind, areas of high and low pressure) and in the hydrosphere (rivers, circulation of water in lakes, ocean currents) alone would account for the transport of organic compounds if they were stable and if all these compounds were molecularly distributed in these phases. However, this particular case is observed only for volatile chlorofluorocarbons and tetrachloromethane. For most organic compounds, complex adsorption/desorption processes on finely dispersed particle phases in the air and water as well as abiotic and biotic transformations determine the transport behavior. The global fate of a compound includes its accumulation as well as its decomposition in defined environmental compartments. Both phenomenon may have long-term consequences in the af-fected areas; this is indicated by the accumulation of polychlorobiphenyls and analogous compounds in marine mammals and deep-sea fauna, and is evident in the decomposition of chlorofluorocarbons in the stratosphere. The accepted definition of the level of a risk, the product of the probability of an event and the potential amount of damage, takes on a new dimension when viewed from a global perspective-especially when one further connects the extent of the damage to the possible means of correction. It is the responsibility of scientists to point out the irreparable regional to global consequences directly and indirectly connected to the production of chemicals and to provide suggestions for prevention. Politicians can only react by applying their methods to limit the damage; however, they cannot generate any solutions based on science.     

浅议基于《有机化合物命名原则2017》的复杂有机化合物

In order to promote and keep pace with the teaching of new nomenclature of organic compounds, some important revisions about teaching organic nomenclature suggested in Nomenclature of Organic Compounds 2017 were summarized. We proposed some concrete suggestions for using the new principles of the Nomenclature of Organic Compounds 2017 to name the complex organic compounds.     

化学师范生变化观及其教学认识的调查研究*

使用开放性问卷与访谈法,以广东省某高校的43名化学师范生为研究对象,测查了他们的变化观及变化观的教学认识。结果表明化学师范生的变化观(尤其是哲学视角变化观)与变化观教学(包括渗透变化观的教学内容和培养变化观的教学策略)的认识仍有待提高。文末据此对我国化学师范生教育及相关研究提出了建议。     

基于风险认知和决策能力培养的元素化合物教学——以“钠的性质”为例

以“钠的性质”为例,探究“金属钠遇水为什么会燃烧爆炸?”“遇到因金属钠而发生的事故该怎么办?”等问题,将风险认知和决策能力培养聚集于课堂,延伸至课外。     

非羧酸类有机化合物及其酸性

有机化学中，除了羧酸之外，存在一些不含有羧基官能结构，但仍然可在一定条件下通过相关C-H键或O-H键的异裂解离出质子，表现出一定酸性，甚至是显著酸性的有机化合物，曾被称之为假酸或碳素酸，总结了几类典型的非羧酸类有机化合物及其酸性，包括硝基甲烷、含有α-H的醛酮类化合物、乙酰乙酸乙酯、乙酰丙酮、丙二酸二乙酯、末端炔烃、醇、酚及其衍生物，并从电子结构特征出发，简要分析了其酸性的本质和影响因素，有助于全面系统学习和认识这些有机化合物的酸性。     

Toxicity of Chlorinated Organic Compounds: Effects of the Introduction of Chlorine in Organic Molecules

Industrial “chlorine chemistry” is accused of polluting the environment with its products and having adverse effects on health. The accusation has been followed by the demand that this ill-defined branch of chemistry be simply abolished, a demand which has been repeated vigorously now for years. It grew out of misgivings such as those summarized here: 1. A number of polychlorinated cyclic compounds are very stable and highly lipophilic so that they accumulate in the environment and affect mankind through the food chain. Prominent examples are chlorinated pesticides, biphenyls, dibenzodioxins, and dibenzofurans. 2. Many chlorinated compounds are toxic for man and animals. Their genotoxicity (mutagenicity and carcinogenicity) plays a role in risk assessment; more and more chlorinated organic compounds are being shown to be carcinogenic and classified accordingly. To date there are no comprehensive reviews of the toxicology of chlorinated organic compounds. The present treatise is the result of an attempt to analyze the situation systematically. It makes generalizations as to the kind and degree of toxicity of the most important classes of chlorinated organic compounds and elaborates recommendations for reduction and avoidance of risk during production, occupational handling, and general use.     

Computational and Theoretical Chemistry in Structure-Reactivity Studies of Organophosphorus Compounds

Computational multivariation analysis, molecular orbital calculation as well as molecular mechanics study were used for the qualitative and quantitative evaluation of the relationship between chemical structure and reactivity of organophosphorus compounds.     

Photochemical and Electrochemical Carbon Dioxide Utilization with Organic Compounds

In the last few years, photochemical and electrochemical CO₂ transformations have attracted increasing attention in response to topical interest in renewable energy and green chemistry. The present minireview offers an overview about the current approaches for the photochemical and electrochemical carbon dioxide fixation with organic compounds. Valuable products, including carboxylic acids and heterocyclic compounds, are accessible through carboxylation and carboxylative cyclization, respectively. In photochemical and electrochemical processes, photo‐ or electro‐induced radical ions or other high‐energy organic compounds are considered as key intermediates to react with CO₂. Besides, activation of CO₂ to produce radical anion has also been reported.     

中学化学实验中的科学风险认知和决策意识

对中学化学实验中的科学风险认知和决策意识进行探索与思考,分析了中学化学实验中科学风险教育的现状,探讨了在化学实验中进行科学风险认知和决策的方式,阐述了在化学实验中培养学生科学风险认知和决策意识的意义。     

Organic Nitrates of Isoprene as Atmospheric Trace Compounds

The occurrence in ambient air of organic nitrates of isoprene, which can form according to Equation (1), was established for the first time. The analytical method was a combination of NP-HPLC and capillary gas chromatography with mass-selective detection by means of (methane)-NCI after high-volume sample collection (NCI=negative chemical ionization).     

The Many Roles of Quantum Chemical Predictions in Synthetic Organic Chemistry

This account discusses representative case studies for various applications of quantum chemical calculations in synthetic organic chemistry. These include confirmation of target structures, methodology development, and catalyst design. These examples demonstrate how predictions from quantum chemical calculations can be utilized to streamline synthetic efforts.     

Covalent Organic Frameworks and Cage Compounds: Design and Applications of Polymeric and Discrete Organic Scaffolds

Porous organic materials are an emerging class of functional nanostructures with unprecedented properties. Dynamic covalent assembly of small organic building blocks under thermodynamic control is utilized for the intriguingly simple formation of complex molecular architectures in one‐pot procedures. In this Review, we aim to analyze the basic design principles that govern the formation of either covalent organic frameworks as crystalline porous polymers or covalent organic cage compounds as shape‐persistent molecular objects. Common synthetic procedures and characterization techniques will be discussed as well as more advanced strategies such as postsynthetic modification or self‐sorting. When appropriate, comparisons are drawn between polymeric frameworks and discrete organic cages in terms of their underlying properties. Furthermore, we highlight the potential of these materials for applications ranging from gas storage to catalysis and organic electronics.     

Oxidative Transformations of Organic Compounds Mediated by Redox Molecular Sieves

Zeolites are viewed by some as the “philosopher's stone” of modern chemistry.^[1] They are more or less indispensable in oil refining and petrochemicals manufacture where they are widely applied as solid acid catalysts. More recently attention has been focused on their use in the manufacture of fine chemicals. The synthetic utility of zeolites and related molecular sieves (zeotypes) has been considerably extended by the incorporation of redox metals into their frameworks. The resulting redox molecular sieves catalyze a variety of selective oxidations under mild conditions in the liquid phase. Their structural diversity–including variation of the redox metal, incorporation of metal complexes, and the size and polarity of the micropores–provides the possibility of designing tailor-made solid catalysts (“mineral enzymes”) for liquid-phase oxidations with clean oxidants such as O₂, H₂O₂, and RO₂H. Hence, they have enormous potential in industrial organic synthesis as environmentally friendly alternatives to traditional oxidations employing inorganic oxidants in stoichiometric amounts. A primary aim of this review is to familiarize organic chemists with the synthetic potential of redox molecular sieves. An outline of their synthesis, structures, and chemical properties, highlighting their unique advantages, is followed by a discussion of general (mechanistic) features that influence the choice of a suitable catalyst for a particular type of oxidation. The main part of the review deals with the oxidation of various substrates of synthetic interest–such as alkanes, alkenes, (alkyl)arenes, alcohols, and amines–and emphasizes the advantages of redox molecular sieves (including selectivity and stability) over their homogeneous counterparts. New directions towards truly biomimetic solid catalysts, for example zeolite-encapsulated chiral metal complexes as heterogeneous catalysts for asymmetric oxidations, are high-lighted.     

和医学相关有机化合物绿色鉴别实验的设计*

为了将医用化学实验中“有机化合物的鉴别”实验更加密切地与医学相关专业结合,并提高实验操作的安全性,降低化学试剂的毒性与刺激性,甄选出一系列与医学密切相关的有机化合物作为待鉴别试剂,同时设计绿色环保、安全低毒、现象明显、操作简便、成本低廉的鉴别方法,为学生实验方案的设计提供指导。以期提高医学生学习的积极性与主动性,促进学生灵活运用知识分析问题、解决问题,为相关教学工作的改进提供借鉴意义。     

有机化合物命名原则(2017)的简化及在有机化学教材中的应用

在对《有机化合物命名原则(2017)》基本原则进行梳理的基础上,对一些调整后的规则进行简化,使其适用于本科有机化学教学中有机化合物的命名。并结合实例,对命名的原则及用法进行说明。     

基于学科理解的认识视角研究——以有机物分子组成与结构主题为例

学科理解对教师教学的主要价值在于凝练学科本原性问题、抽提认识视角、厘清认识思路及建构主题概念层级结构,其中认识视角决定了理解问题的深刻程度,能够指引认识思路的发展,具有学科认识论层面的重要价值。本研究探讨学科理解视域下的认识视角是如何抽提并发展的,以有机物分子组成与结构主题为例。通过理解化学史得出抽提认识视角的过程：(1)追溯化学家本原性思想,分析概念的学科功能;(2)基于学科功能抽提认识视角,纵向体会认识视角的发展性;(3)基于矛盾冲突丰富认识视角,横向体会认识视角的多面性;(4)基于认识视角发展结构化、本原性的理解。