Foundations of Chemistry最新文献

The debate between ontological reductionists and emergentists in chemistry has revolved around quantum mechanics. What Franklin and Seifert (BJPS 2020) add to the long-running dispute is an attention to the measurement problem. They contend that all three realist interpretations of the quantum formalism capable of resolving the measurement problem also obviate any need for chemical emergence. I push their argument further, arguing that the realist interpretations of quantum mechanics actually subvert the basis for reduction as well, by undercutting the idea that fundamental physical particles are actual parts of molecules. With both reduction and traditional synchronic emergence pictures ruled out, the only option for realists about quantum chemistry is strong Thomistic emergence.

This article describes a descriptive-qualitative method for analyzing and reviewing several textbooks for high school as samples commonly used by teachers and students in their teaching–learning to reveal possible misconceptions. This study focused on the subjects of quantum numbers and electronic configuration. From the advanced literature review to analyze the samples the occurrence of various misconceptions was noted. All textbooks described correctly the four symbols of quantum numbers, but none correlates correctly the magnetic-angular quantum number to the Cartesian labeled orbitals. All textbooks consider mistakenly the meaning of aufbau as the building-up energy of orbitals by following (n + ℓ, n) rules on describing the electronic configuration for all atoms. Only one textbook states that the electronic configuration of transition metal atoms (3d series) can be described in the following order of shell (n), thus giving rise to two types of electronic configurations, [Ar] 3d 4s (Type I) beside [Ar] 4s 3d (Type II), leading further misconception. All textbooks described favorably an unpaired electron of m_s =  + ½ due to the specific agreement, which is a potential misconception in applying Hund’s rule. In drawing the diagram boxes of orbitals, they are arranged in increasing or decreasing the numeric m_ℓ, due to the specific agreement, and again leading to a potential misconception on describing the quantum number of electrons issued. Three textbooks introduced the terms of the last and the xth electron associated with the quantum numbers, leading to serious further misconceptions. No books stated that the ordering energy of the (n + ℓ, n) rule is true only for the first twenty atoms.

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.