Foundations of Chemistry最新文献

The concept of green chemistry dominated the imagination of environmentally-minded chemists over the last thirty years. The conceptual frameworks laid by the American Environmental Protection Agency scholars in the 1990s constitute today the core of a line of thinking aimed at transforming chemistry into a sustainable science. And yet, in the shadow of green chemistry, a broader, even if less popular, concept of sustainable chemistry started taking shape. Initially, it was either loosely associated with green chemistry or left undefined as a distinct but generaly different approach. In such a vague form, it was endorsed by the organizations such as OECD and the IUPAC in the late 1990s. It was not until the 2010s however, when it solidified as a separate more embracing and more overarching tradition that could compete with green chemistry by offering insights that the latter lacked. Sustainable chemistry seeks to transcend the narrow focus on chemical synthesis and embrace a much more holistic view of chemical activities including social responsibility and sustainable business models. Due to an interesting historical coincidence, it was in Germany where sustainable chemistry took roots and became institutionalized for the first time. It was thanks to German exceptionalism and the unwillingness of German scholars to embrace the “green” terminology originating from the US, the concept of sustainable chemistry could safely mature and develop in the German-speaking world, before reaching a high degree of formalization with dedicated journals, founding articles, and programmatic principles aspiring to transform the entire chemical enterprise in the years to come.

Dr. K. Wray (2022) questioned my suggestion that T. W. Richards should be included as one of the scientists who contributed to the discovery of isotopes. This article provides additional support for inclusion of Richards as a contributor to the discovery.

Based upon the demarcation between Elementalism and Atomism Chemistry from the perspective of the long-term history of chemistry, the authors re-examine the Berthollet-Proust controversy on the three types of chemical compounds, pointing out that Berthollet proposed the law of indefinite proportions by deduction, while Proust proposed the law of definite proportions by induction. The controversy is beyond the framework of affinity chemistry and entail a synthesis of meta-chemical thinking and experiments. Proust’s discovery of the law of definite proportions not only function as Bacon’s “instances of lamp” to invoke Dalton and other atomism chemists to envision atomism, but also served as a bridge linking the two meta-chemistries. John Dalton, the third choice, envisioned his atomism by abduction. The case study on “the Berthollet-Proust controversy and Dalton’s resolution” mandates a reinvestigation of the crucial role of the system of experiments and the evolution of chemistry according to the demarcation between the established branches of Elementalism and Atomism Chemistry.

Examples are given of applications by Pauling, Mulliken, Marcus and G.E.Kimball of the three Pythagorian means to formulate the scales of electronegativity of the elements, to the calculations of rate constants of electron transfer cross-reactions, to the calculation of the observed rate constant as function of activation and diffusion rate constants in the case of mixed reaction-diffusion rates and to the calculation of the effective diffusion coefficient in solution of a salt AB as a whole from the diffusion coefficients of the ions in which it dissociates.

Despite decades of research and thought on the meaning and identification of revolutions in science, there is no generally accepted definition for this concept. This paper presents 13 different characteristics that have been used by philosophers and historians of science to characterize revolutions in science, in general, and in chemistry, in particular. These 13 characteristics were clustered into six independent factors. Suggestions are provided as to the use of these characteristics and factors to evaluate historical events as to their possible categorization as revolutions in chemistry. Challenges to the goal of creating a consensus definition of “revolutions in science” are also presented in this publication.

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.

Many pictures of the bonding of B₂H₆ have been presented over the past century, starting with a strong effort to force B₂H₆ to fit the ideas that were current for C₂H₆ and building to now viewing the molecular orbital model as the basis for a new transferrable concept of a 3-center-2-electron bond that stimulates creation of new chemistry. Even now, though, some would view this special bond more like a protonated double bond. The historical development of the current understanding of bonding in B₂H₆ is summarized here.

In 1869, two distinguished scientists, Dimitri Mendeleev and Lothar Meyer, discovered a certain periodicity among the chemical characteristics of the then known elements. Both developed first versions of the periodic table, independently. In the wake of the 150th anniversary, UNESCO proclaimed 2019 the “International Year of the Periodic Table of Chemical Elements”. Two lucid and detailed studies on the periodic table—accompanied by smaller studies on the occasion of the anniversary—have been published, recently, one of them analysing the scientific history, contributing to the (philosophical) theory of science (Eric Scerri), the other analysing the structures, patterns, and irregularities of the table (Geoff Rayner-Canham). Both studies are profound and vivid examples how scientific progress works. They illustrate that even in hard sciences—mirroring Merton’s concept of middle range theory—the required degree of exactness can remain on an intermediate level, as imperfection allows interpretations which could not (yet) be reached by pure mathematics and logic. Both of these brilliant studies provide valuable material, especially for a social science, to better understand how scientific ideas develop, how the power of visualization helps shape ideas, and how contingency is absorbed by the scientific process.

Recent publications by several leading philosophers of chemistry have focused on the definition, scope, utility, and nomenclature of issues dealing with acidity and basicity. In this paper, molecular orbital theory is used to explain all acid–base reactions, concluding that the interaction of the highest occupied molecular orbital (HOMO) of one substrate, “the base,” with the lowest unoccupied molecular orbital (LUMO) of a second substrate, “the acid,” determines the reactivity of such systems. This paradigm provides an understanding of all acid–base reactions as well as other reactions which, on the surface, may not seem like acid–base reactions but which have fundamental underpinnings of that kind of chemistry. Rather than being unable to determine a unified understanding of acidity and basicity as suggested in the philosophy of chemistry literature, we propose that acidity and basicity fit securely in a classification of many other reactions that, using classical chemistry knowledge, pre-quantum chemistry, would not be possible. We strongly support the use of all scientific knowledge and experience in the development of the ideas in the philosophy science. We further suggest increased interactions between philosophers of science and scientists, so that all scholars benefit from the values, knowledge, and perspectives of other disciplines.