{"title":"Why do prima facie intuitive theories work in organic chemistry?","authors":"Hirofumi Ochiai","doi":"10.1007/s10698-023-09470-1","DOIUrl":null,"url":null,"abstract":"<div><p>In modern German ‘Anschauung’ is translated as intuition. But in Kant’s technical philosophical context, it means an intuition derived from previous visualizations of physical processes in the world of perceptions. The nineteenth century chemists’ predilection for Kantian Anschauung led them to develop an intuitive representation of what exists beyond the bounds of the senses. Molecular structure is one of the illuminating outcomes. (Ochiai 2021, pp. 1–51) This mental habit seems to be dominant among chemists even in the twentieth century, as is illustrated by the electronic theory of organic chemistry and the frontier orbital theory as well. The former assumes that (1) bonds are paired electrons shared by bonded atoms—in fact, electrons in molecules are not localized in bonds; (2) the difference of electronegativities between bonded atoms causes electron drifts—expressed by the curly arrow—that result in bond formation or bond cleavage. The latter focuses on the orbitals that make the greatest contribution to the energy of a system undergoing electron delocalization, while the LCAO method says, as is suggested by the word Linear Combination of Atomic Orbitals, molecular orbitals should be constructed from all of the atomic orbitals that have the appropriate symmetry. In other words, every molecular orbital contributes to some extent to the electronic state of a molecule. The curly arrow in the electronic theory and the orbital lobe in the frontier orbital theory illustrate an intuitive character of these theories. Although both theories rely on such simple and qualitative models rather than mathematically rigid quantum mechanical calculations, they are successful in explaining, predicting, and designing chemical reactions. What makes these <i>prima facie</i> intuitive theories so successful? In this study we address this problem from a historical and philosophical as well as scientific point of view. The key to solve this problem is that they are concerned with only bond formation or bond cleavage, in which the localized-bond principle holds.</p></div>","PeriodicalId":568,"journal":{"name":"Foundations of Chemistry","volume":"25 3","pages":"359 - 367"},"PeriodicalIF":1.8000,"publicationDate":"2023-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Foundations of Chemistry","FirstCategoryId":"92","ListUrlMain":"https://link.springer.com/article/10.1007/s10698-023-09470-1","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"HISTORY & PHILOSOPHY OF SCIENCE","Score":null,"Total":0}
引用次数: 0
Abstract
In modern German ‘Anschauung’ is translated as intuition. But in Kant’s technical philosophical context, it means an intuition derived from previous visualizations of physical processes in the world of perceptions. The nineteenth century chemists’ predilection for Kantian Anschauung led them to develop an intuitive representation of what exists beyond the bounds of the senses. Molecular structure is one of the illuminating outcomes. (Ochiai 2021, pp. 1–51) This mental habit seems to be dominant among chemists even in the twentieth century, as is illustrated by the electronic theory of organic chemistry and the frontier orbital theory as well. The former assumes that (1) bonds are paired electrons shared by bonded atoms—in fact, electrons in molecules are not localized in bonds; (2) the difference of electronegativities between bonded atoms causes electron drifts—expressed by the curly arrow—that result in bond formation or bond cleavage. The latter focuses on the orbitals that make the greatest contribution to the energy of a system undergoing electron delocalization, while the LCAO method says, as is suggested by the word Linear Combination of Atomic Orbitals, molecular orbitals should be constructed from all of the atomic orbitals that have the appropriate symmetry. In other words, every molecular orbital contributes to some extent to the electronic state of a molecule. The curly arrow in the electronic theory and the orbital lobe in the frontier orbital theory illustrate an intuitive character of these theories. Although both theories rely on such simple and qualitative models rather than mathematically rigid quantum mechanical calculations, they are successful in explaining, predicting, and designing chemical reactions. What makes these prima facie intuitive theories so successful? In this study we address this problem from a historical and philosophical as well as scientific point of view. The key to solve this problem is that they are concerned with only bond formation or bond cleavage, in which the localized-bond principle holds.
在现代德语中,“Anschauung”被翻译成直觉。但在康德的技术哲学语境中,它指的是一种直觉,来自于对感知世界中物理过程的先前可视化。19世纪的化学家偏爱康德的安朔理论,这使他们发展出一种直观的表征,来描述存在于感官之外的东西。分子结构是其中一个具有启发性的成果。(Ochiai 2021, pp. 1-51)即使在20世纪,这种思维习惯似乎在化学家中占主导地位,正如有机化学的电子理论和前沿轨道理论所说明的那样。前者假设(1)键是由成键原子共享的成对电子——事实上,分子中的电子并不局限于键中;(2)键合原子之间电负性的差异导致电子漂移——用卷曲箭头表示——导致键形成或键裂解。后者侧重于对经历电子离域的系统的能量贡献最大的轨道,而LCAO方法则认为,正如原子轨道线性组合一词所暗示的那样,分子轨道应该由所有具有适当对称性的原子轨道构建而成。换句话说,每个分子轨道都在一定程度上影响着分子的电子态。电子理论中的卷曲箭头和前沿轨道理论中的轨道瓣说明了这些理论的直观特征。尽管这两种理论都依赖于如此简单和定性的模型,而不是数学上严格的量子力学计算,但它们在解释、预测和设计化学反应方面都取得了成功。是什么让这些初步直觉理论如此成功?在这项研究中,我们从历史和哲学以及科学的角度来解决这个问题。解决这一问题的关键在于,它们只关注键的形成或键的解理,在这种情况下,局域键原理是成立的。
期刊介绍:
Foundations of Chemistry is an international journal which seeks to provide an interdisciplinary forum where chemists, biochemists, philosophers, historians, educators and sociologists with an interest in foundational issues can discuss conceptual and fundamental issues which relate to the `central science'' of chemistry. Such issues include the autonomous role of chemistry between physics and biology and the question of the reduction of chemistry to quantum mechanics. The journal will publish peer-reviewed academic articles on a wide range of subdisciplines, among others: chemical models, chemical language, metaphors, and theoretical terms; chemical evolution and artificial self-replication; industrial application, environmental concern, and the social and ethical aspects of chemistry''s professionalism; the nature of modeling and the role of instrumentation in chemistry; institutional studies and the nature of explanation in the chemical sciences; theoretical chemistry, molecular structure and chaos; the issue of realism; molecular biology, bio-inorganic chemistry; historical studies on ancient chemistry, medieval chemistry and alchemy; philosophical and historical articles; and material of a didactic nature relating to all topics in the chemical sciences. Foundations of Chemistry plans to feature special issues devoted to particular themes, and will contain book reviews and discussion notes. Audience: chemists, biochemists, philosophers, historians, chemical educators, sociologists, and other scientists with an interest in the foundational issues of science.