What did “theory” mean to nineteenth-century chemists?

Some recent philosophers of science have argued that chemistry in the nineteenth century “largely lacked theoretical foundations, and showed little progress in supplying such foundations” until around 1900, or even later. In particular, nineteenth-century atomic theory, it is said, “played no useful part” in the crowning achievement of nineteenth-century chemistry, the powerful subdiscipline of organic chemistry. This paper offers a contrary view. The idea that chemistry only gained useful theoretical foundations when it began to merge with physics, it will be argued, is based on an implicit conception of scientific theory that is too narrow, and too exclusively oriented to the science of physics. A broader understanding of scientific theory, and one that is more appropriate to the science of chemistry, reveals the essential part that theory played in the development of chemistry in the nineteenth century. It also offers implications for our understanding of the nature of chemical theory today.     

物理化学理论体系中的几种基本研究方法

理想模型化法、标准状态法、可逆过程极值法和微元法是物理化学中具有典型学科特征的基本理论研究方法,在物理化学理论体系的形成和发展过程中相应形成并贯穿整个学科。本文从科学方法论的角度,归纳总结了四种理论研究方法的研究目的、处理方法及相应规定和结论,并对它们在物理化学理论体系中的具体应用通过实例予以分析和说明。同时阐述了如果掌握并深刻领会了这些科学研究方法,将有助于学习者构建物理化学宏观知识体系,培养逻辑思维能力,增强分析问题和解决问题能力。     

共轭效应的本质及其在有机反应中的特殊性

共轭效应是有机化学中特别重要的电子效应之一,存在于共轭体系之中;大学有机化学教学目标要求学生掌握并能熟练应用共轭效应理论解决有机化学中的实际问题。由于共轭效应涉及微观认知,学生普遍感觉不易理解。但作为教学重点与难点,又必须掌握;同时也是学生大学毕业后继续深造学习所必须的基础理论知识,理解、掌握并能熟练应用该理论知识解决有机化学中的学习问题显得尤为重要。本文采用密度泛函理论方法计算并给出了3个二烯烃分子轨道中最高占据分子轨道(HOMO)、最低空分子轨道(LUMO)结构图,揭示了共轭体系内部因存在电荷转移现象而产生电子云的平均化本质,表现在键参数中的键长平均化变化。     

Noncovalent interactions in inorganic supramolecular chemistry based in heavy metals. Quantum chemistry point of view

Complexity is a concept that is being considered in chemistry as it has shown potential to reveal interesting phenomena. Thus, it is possible to study chemical phenomena in a new approach called systems chemistry. The systems chemistry has an organization and function, which are regulated by the interactions among its components. At the simplest level, noncovalent interactions between molecules can lead to the emergence of large structures. Consequently, it is possible to go from the molecular to the supramolecular systems chemistry, which aims to develop chemical systems highly complex through intra- and intermolecular forces. Proper use of the interactions previously mentioned allow a glimpse of supramolecular system chemistry in many tasks such as structural properties reflecting certain behaviors in the chemistry of materials, for example, electrical and optical, processes of molecular recognition and among others. In the last time, within this area, inorganic supramolecular systems chemistry has been developed. Those systems have a structural orientation which is defined by certain forces that predominate in the associations among molecules. It is possible to recognize these forces as hydrogen bonding, π-π stacking, halogen bonding, electrostatic, hydrophobic, charge transfer, metal coordination, and metallophilic interactions. The presence of these forces in supramolecular system yields certain properties such as light absorption and luminescence. The quantum theoretical modeling plays an important role in the designing of the supramolecular system. The goal is to apply supramolecular principles in order to understand the associated forces in many inorganic molecules that include heavy metals for instance gold, platinum, and mercury. Relevant systems will be studied in detail, considering functional aspects such as enhanced coordination of functionalized molecular self-assembly, electronic and optoelectronic properties.     

LUMPAC lanthanide luminescence software: Efficient and user friendly

In this study, we will be presenting LUMPAC (LUMinescence PACkage), which was developed with the objective of making possible the theoretical study of lanthanide‐based luminescent systems. This is the first software that allows the study of luminescent properties of lanthanide‐based systems. Besides being a computationally efficient software, LUMPAC is user friendly and can be used by researchers who have no previous experience in theoretical chemistry. With this new tool, we hope to enable research groups to use theoretical tools on projects involving systems that contain lanthanide ions. © 2014 Wiley Periodicals, Inc.     

Quantum chemistry simulation on quantum computers: theories and experiments

It has been claimed that quantum computers can mimic quantum systems efficiently in the polynomial scale. Traditionally, those simulations are carried out numerically on classical computers, which are inevitably confronted with the exponential growth of required resources, with the increasing size of quantum systems. Quantum computers avoid this problem, and thus provide a possible solution for large quantum systems. In this paper, we first discuss the ideas of quantum simulation, the background of quantum simulators, their categories, and the development in both theories and experiments. We then present a brief introduction to quantum chemistry evaluated via classical computers followed by typical procedures of quantum simulation towards quantum chemistry. Reviewed are not only theoretical proposals but also proof-of-principle experimental implementations, via a small quantum computer, which include the evaluation of the static molecular eigenenergy and the simulation of chemical reaction dynamics. Although the experimental development is still behind the theory, we give prospects and suggestions for future experiments. We anticipate that in the near future quantum simulation will become a powerful tool for quantum chemistry over classical computations.     

复杂化学体系的分子模拟研究——2013年诺贝尔化学奖浅析

随着化学科学研究水平的日益提高,人们对物质世界的分子水平的理解也在逐步加深。化学研究中对原理性理解的要求越来越高,也要求越来越准确的定量研究。化学传统上以实验为主,而现代化学对理论具有了强烈依赖性。理论化学的发展取得了巨大进步,成为化学学科的一个重要组成部分。理论与计算化学不但帮助解释实验结果,更提供对实验观察的预言和对材料药物等的合理设计。通过与统计力学和量子力学的紧密结合,在现代计算机技术的支持下分子模拟在化学、材料、生物等学科中得到广泛应用,处理多尺度实际体系的能力越来越强,具有非常广阔的发展前景。但分子模拟作为一个研究手段还需要大力发展,以提高其普适性,使之具有更坚实的理论基础,同时更加系统化和实用化。     

A mathematical approach to chemical equilibrium theory for gaseous systems—I: theory

Equilibrium theory occupies an important position in chemistry and it is traditionally based on thermodynamics. A novel mathematical approach to chemical equilibrium theory for gaseous systems at constant temperature and pressure is developed. Six theorems are presented logically which illustrate the power of mathematics to explain chemical observations and these are combined logically to create a coherent system. This mathematical treatment provides more insight into chemical equilibrium and creates more tools that can be used to investigate complex situations. Although some of the issues covered have previously been given in the literature, new mathematical representations are provided. Compared to traditional treatments, the new approach relies on straightforward mathematics and less on thermodynamics, thus, giving a new and complementary perspective on equilibrium theory. It provides a new theoretical basis for a thorough and deep presentation of traditional chemical equilibrium. This work demonstrates that new research in a traditional field such as equilibrium theory, generally thought to have been completed many years ago, can still offer new insights and that more efficient ways to present the contents can be established. The work presented here can be considered appropriate as part of a mathematical chemistry course at University level.     

Explanation and theory formation in quantum chemistry

In this paper I expand Eric Scerri’s notion of Popper’s naturalised approach to reduction in chemistry and investigate what its consequences might be. I will argue that Popper’s naturalised approach to reduction has a number of interesting consequences when applied to the reduction of chemistry to physics. One of them is that it prompts us to look at a ‘bootstrap’ approach to quantum chemistry, which is based on specific quantum theoretical theorems and practical considerations that turn quantum ‘theory’ into quantum ‘chemistry’ proper. This approach allows us to investigate some of the principles that drive theory formation in quantum chemistry. These ‘enabling theorems’ place certain limits on the explanatory latitude enjoyed by quantum chemists, and form a first step into establishing the relationship between chemistry and physics in more detail.     

配位化学中新型金属配合物的电子结构与成键特点

研究配合物的几何电子构型、阐明配位键的本质是配位化学中重要的理论组成部分。本文在回顾配位化学基本的成键理论基础上,介绍几例近年来具有教科书级别的国内高水平原创工作,重点阐述具有独特芳香性、低氧化态、高配位数以及锕系金属的新型金属配合物的电子结构和成键特点,对丰富和拓展配位化学的基本理论具有重要意义。     

Time-dependent density-functional theory for open electronic systems

Time-dependent density-functional theory(TDDFT)has been successfully applied to predict excited-state properties of isolated and periodic systems.However,it cannot address a system coupled to an environment or whose number of electrons is not conserved.To tackle these problems,TDDFT needs to be extended to accommodate open systems.This paper provides a comprehensive account of the recent developments of TDDFT for open systems(TDDFT-OS),including both theoretical and practical aspects.The practicality and accuracy of a latest TDDFT-OS method is demonstrated with two numerical examples:the time-dependent electron transport through a series of quasi-one-dimensional atomic chains,and the real-time electronic dynamics on a two-dimensional graphene surface.The advancement of TDDFT-OS may lead to promising applications in various fields of chemistry,including energy conversion and heterogeneous catalysis.     

胶体与界面化学的研究进展

胶体与界面化学是研究胶体分散体系和界面现象的一门科学,在能源、材料、生物、化学制造和环境科学等领域具有广泛的应用。近年来,由于先进功能材料、仿生学和生物医药等学科的迅速发展,在纳米尺寸(胶体)的范围内进行分子组装和材料的制备已经引起了人们的高度关注。过去两年里,中国胶体与界面化学领域的科学家的创新性研究工作层出不穷,国际影响力日益提升,所获得的研究成果越来越受到国际同行的关注。这些成果可概括为:(1)系列新型有序分子组合体的构建及其在生物医药领域的应用,尤其是超分子组装、表面图案化有序组装材料的设计和应用;(2)胶体与界面化学方法在微纳米功能材料合成中的应用,包括形貌可控的无机材料、有机-无机复合功能材料、贵金属纳米材料以及小分子凝胶的合成及其应用;(3)胶体与界面化学在生物传感领域的新应用;(4)胶体与界面化学研究新方法。作为一门与实际应用密切结合的学科,现代经济社会为胶体与界面化学的发展提供了广阔的空间。可以预期,未来胶体与界面化学将更注重其基本的物理化学问题,如:新颖有序分子组合体的构建和理论认识;功能性微纳米材料界面结构与性能调控的理论指导。此外,新的手段和方法在胶体与界面体系的不断渗透,将不断产生新的学科交叉点,从而有力地促进胶体与界面化学的学科发展。共引用参考文献96篇。     

From organometallic and polymer chemistry to applied materials science: transition metal catalyzed synthesis of polyolefins and polyolefin-based high-performance materials

A brief history of the development of transition metal-catalyzed olefin polymerization including the present status of polyolefin chemistry is given. The entire evolution of polyolefin chemistry will be outlined, giving ample attention to the development in the catalytic systems. Starting with the first generation PP catalysts (TiCl₃/AlClEt₂), the success story of organometallic chemistry, which resulted in modern supported and unsupported single site systems and finally functional group-tolerant group VIII systems will be summarized. Where applicable, examples of technical application will be given. Additionally, organometallic chemistry responsible for selectivity but also for termination reactions as well as the various “living” systems and the adherent implications for materials science will be discussed. Finally, the impact of related transition metal-catalyzed metathesis chemistry on the area of specialty materials will be outlined.     

Inverse‐Electron‐Demand Diels–Alder Reactions: Principles and Applications

Inverse‐electron‐demand Diels–Alder (iEDDA) reactions are an intriguing class of cycloaddition reactions that have attracted increasing attention for their application in bioorthogonal chemistry, the total synthesis of natural products, and materials science. In many cases, the application of the iEDDA reaction has been demonstrated as an innovative approach to achieve target structures. The theoretical aspects of this class of reactions are of particular interest for scientists as a means to understand the various factors, such as steric strain and electron density of the attached groups, that govern the reaction and thus to elucidate the reaction mechanism. This review aims to summarize both theoretical investigations and application‐driven research work on the iEDDA reaction. First, the historical aspects and the theoretical basis of the reaction, especially recent advances in time‐dependent density functional theory (TD‐DFT) calculations, as well as catalysis strategies will be highlighted and discussed. Second, the applications of this novel reaction in the context of materials science, bioorthogonal chemistry, and total synthesis of natural products will be elaborated with selected recent examples. The challenges and opportunities of the iEDDA reaction will be highlighted to give more insight into its potential applications in many other research areas.     

Combined Theoretical and Experimental Studies of Sodium Battery Materials

Owing to developments in theoretical chemistry and computer power, the combination of calculations and experiments is now standard practice in understanding and developing new materials for battery systems. Here, we briefly review our recent combined studies based on density functional theory and molecular dynamics calculations for electrode and electrolyte materials for sodium‐ion batteries. These findings represent case studies of successful combinations of experimental and theoretical methods.