Chemical Explanation

We present some ideas on logical process descriptions, using relations from the DIO (Drug Interaction Ontology) as examples and explaining how these relations can be naturally decomposed in terms of more basic structured logical process descriptions using terms from linear logic. In our view, the process descriptions are able to clarify the usual relational descriptions of DIO. In particular, we discuss the use of logical process descriptions in proving linear logical theorems. Among the types of reasoning supported by DIO one (...) can distinguish both (1) basic reasoning about general structures in reality and (2) the domain-specific reasoning of experts. We here propose a clarification of this important distinction between (realist) reasoning on the basis of an ontology and rule-based inferences on the basis of an expert’s view. (shrink)

The periodic table represents and organizes all known chemical elements on the basis of their properties. While the importance of this table in chemistry is uncontroversial, the role that it plays in scientific reasoning remains heavily disputed. Many philosophers deny the explanatory role of the table and insist that it is “merely” classificatory. In particular, it has been claimed that the table does not figure in causal explanation because it “does not reveal causal structure”. This paper provides an analysis of (...) what it means to say that a scientific figure reveals causal structure and it argues that the modern periodic table does just this. It also clarifies why these “merely” classificatory claims have seemed so compelling–this is because these claims often focus on the earliest periodic tables, which lack the causal structure present in modern versions. (shrink)

During the 1930s and 1940s, American physical organic chemists employed electronic theories of reaction mechanisms to construct models offering explanations of organic reactions. But two molecular rearrangements presented enormous challenges to model construction. The Claisen and Cope rearrangements were predominantly inaccessible to experimental investigation and they confounded explanation in theoretical terms. Drawing on the idea that models can be autonomous agents in the production of scientific knowledge, I argue that one group of models in particular were functionally autonomous from the (...) Hughes–Ingold theory. Cope and Hardy’s models of the Claisen and Cope rearrangements were resources for the exploration of the Hughes–Ingold theory that otherwise lacked explanatory power. By generating ‘how-possibly’ explanations, these models explained how these rearrangements could happen rather than why they did happen. Furthermore, although these models were apparently closely connected to theory in terms of their construction, I argue that partial autonomy issued in extra-logical factors concerning the attitudes of American chemists to the Hughes–Ingold theory. And in the absence of a complete theoretical hegemony, a degree of consensus was reached concerning modelling the Claisen rearrangement mechanism.Keywords: Models; Explanation; Physical organic chemistry; Rearrangements. (shrink)

Building upon Nancy Cartwright's discussion of models in How the Laws of Physics Lie, this paper addresses solid state research in transition metal oxides. Historical analysis reveals that in this domain models function both as the culmination of phenomenology and the commencement of theoretical explanation. Those solid state chemists who concentrate on the description of phenomena pertinent to specific elements or compounds assess models according to different standards than those who seek explanation grounded in approximate applications of the Schroedinger equation. (...) Accurate accounts of scientific debate in this field must include both perspectives. (shrink)

I apply James Woodward’s interventionist theory of causation to organic chemistry, modelling three different ways that chemists are able to manipulate the reaction conditions in order to control the outcome of a reaction. These consist in manipulations to the reaction kinetics, thermodynamics, and whether the kinetics or thermodynamics predominates. It is possible to construct interventionist causal models of all of these kinds of manipulation, and therefore to account for them using Woodward’s theory. However, I show that there is an alternate, (...) more illuminating way of thinking about the third kind of reaction control, according to which chemists are thought of as manipulating which causal system is instantiated. I show that our ability to manipulate which system is instantiated is an important part of our ability to control the world, as is therefore especially relevant to interventionism. Thus, considering examples from organic chemistry leads to the identification of an important extension to Woodward’s theory. Finally, this investigation into reaction control in organic chemistry also has a more general implication: it suggests that interventionism results in a version of pragmatism about causation. (shrink)

Next SectionOne of the indisputable signs of the progress made in organic chemistry over the last two hundred years is the increased ability of chemists to manipulate, control, and design chemical reactions. The technological expertise manifest in contemporary synthetic organic chemistry is, at least in part, due to developments in the theory of organic chemistry. By appealing to a notable chemist's attempts to articulate and codify the heuristics of synthetic design, this paper investigates how understanding theoretical organic chemistry facilitates progress (...) in synthetic organic chemistry. The picture that emerges of how the applications of organic chemistry are grounded in its theory is contrasted with both standard and some more contemporary philosophical accounts of the applications of science. IntroductionTotal Synthesis as Applied ScienceUnderstanding Organic ChemistryThe Heuristics of Synthetic DesignAn Example: LongifoleneConclusion. (shrink)

This paper surveys some ways in which the chemical realm can be described and outlined in terms of the concept of supervenience. The particular contours of general chemical theory provide a ready basis for interpretation of determination, covariance, and nonreduction—the characteristic metaphysical facets of the supervenience relation—in mutual terms. Building on this, the extent to which chemically characterized properties and entities can be described in terms of a supervenience-scaffolded structure represents a particularly vivid application that philosophers in general interested in (...) supervenience would do well to attend to. In addition, the model of chemical supervenience given here can be used as a rubric on which to decide on issues already raised by philosophers of chemistry. (shrink)

This article examines a scientific controversy that raged for twenty years in physical organic chemistry during the second half of the twentieth century. After explaining what was at stake in the non-classical ion debate, I attempt—by examining the methodological reflections of some of the participants—a partial explanation of what sustained this controversy, particularly during its early stages. Instead of suggesting a breakdown of scientific method or the unavoidable historical contingency of scientific development, the endurance of this controversy instead reveals the (...) heuristic and pragmatic character of many of the explanations and predictions generated by theoretical organic chemistry. The results in this case are used to suggest a new role for the study of scientific controversies in revealing the economics of scientific inquiry. 1 Introduction2 The Non-classical Ion Debate3 Models for the 2-Norbornyl System4 Soft Theories and Reasoning by Analogy5 Scientific Controversy and the Non-classical Ion Debate6 Conclusion. (shrink)

The most immediate reason why chemists are unenthusiastic about the philosophy of science is the historic hostility of important philosophers, to the concept of atoms. (Without atoms, discovery in chemistry would have proceeded with glacial slowness, if at all, in the last 200 years.) Other important reasons include the anti-realist influence of the philosophical dogmas of logical positivism, instrumentalism, of strict empiricism. Though (as has been said) these doctrines have recently gone out of fashion, they are still very influential.A diagram (...) of the methodology of experimental research is proposed, in the form of a flow sheet, with feedback. The model is developed as a multi-level expansion of a diagram of the hypothetico-deductive model. It recognizes that strong mutual support, or interlocking, of research endeavors is important, at the underlying level or levels where explanatory causation contributes to scientific understanding. (Mutual support at the laboratory level is generally weak or trivial.) The multiplicity of explanatory levels, and the interlocking, point to solutions to some well-known problems, such as the origin of the hypotheses, and even a resolution to the underdetermination problem. (shrink)

A major obstacle to chemistry being a deductive science is that its core concepts very often are defined in a circular manner: it is impossible to explain what an acid is without reference to the complementary concept of a base. There are many such dual pairs among the core concepts of chemistry. Such circulation of concepts, rather than an infirmity chemistry is beset with, is seen as a source of vitality and dynamism.

The drastically increasing availability ofmodern computers coupled with the equally drasticallylower cost of a given amount of computer power inrecent years has resulted in the evolution of thetraditional experimental/theoretical dichotomy inchemistry into anexperimental/theoretical/computational trichotomy. This trichotomy can be schematically represented by atriangle with experimental,theoretical, and computational chemistry at the threevertices. The ET and EC edges of the ETC triangledepict the uses of theoretical and computationalchemistry, respectively, to predict and interpretexperimental results. The TC edge depicts therelationship between theoretical and computationalchemistry. Mathematics (...) plays an increasing role in allaspects of chemistry, particularly theoreticalchemistry, and has led to the evolution of thediscipline of mathematical chemistry. Research inmathematical chemistry can be considered to lie on achemistry-mathematics continuum depending on therelative depths of the underlying chemistry andmathematics. Examples of the author's own researchlying near each end of the chemistry-mathematicscontinuum include his work on applications of graphtheory and topology in inorganic coordination andcluster chemistry lying near the chemistry end and hiswork on chirality algebra lying near the mathematicsend. The general points in this essay are illustratedby an analysis of the roles of computational andtheoretical chemistry in developing an understandingof structure and bonding in deltahedral boranes andrelated carboranes. This work has allowed extensionof the concept of aromaticity from two dimensions asin benzene and other planar hydrocarbons to the thirddimension in deltahedral boranes. (shrink)

The current status of explanation worked out by Physics for the Periodic Law is considered from philosophical and methodological points of view. The principle gnosiological role of approximations and models in providing interpretation for complicated systems is emphasized. The achievements, deficiencies and perspectives of the existing quantum mechanical interpretation of the Periodic Table are discussed. The mainstream ab initio theory is based on analysis of selfconsistent one-electron effective potential. Alternative approaches employing symmetry considerations and applying group theory usually require some (...) empirical information. The approximate dynamic symmetry of one-electron potential casts light on the secondary periodicity phenomenon. The periodicity patterns found in various multiparticle systems (atoms in special situations, atomic nuclei, clusters, particles in the traps, etc) comprise a field for comparative study of the Periodic Laws found in nature. (shrink)

Attempts to explain the periodic system as a manifestation of regularities in the structure of the atoms of the elements are as old as the system itself. The paper analyses some of the most important of these attempts, in particular such works that are historically connected with the recognition of the electron as a fundamental building block of all matter. The history of the periodic system, the discovery of the electron, and ideas of early atomic structure are closely interwoven and (...) transcend the physics–chemistry boundary. It is pointed out that J. J. Thomson's discovery of the electron in 1897 included a first version of his electron atomic model and that it was used to suggest how the periodic system could be understood microphysically. Thomson's theory did not hold what it promised, but elements of it were included in Niels Bohr's first atomic model. In both cases, Thomson's and Bohr's, the periodic system played an important role, heuristically as well as justificatory. (shrink)

In 1870–75 Markovnikov enunciatedan empirical Rule which generalized theregiochemical outcome of addition reactions tounsymmetrical alkenes. This Rule remaineduseful for about 75 years, until suchreactions came to be better understood inmechanistic terms. Thereafter the Rule couldbe deduced from principles of relativecarbocation stabilization and ceased to servean independent purpose. Nevertheless, mostorganic textbooks continue to cite it (oftenin a historically inaccurate, anachronisticway), thereby distracting student attentionfrom the underlying principles. This paperadvocates doing away with the Rule in organicchemistry textbooks and classrooms.

This essay analyzes the historical and philosophical context that led to the basic concepts of stereochemistry proposed by Van’t Hoff and Le Bel. Although it is now well established that the key idea of tetrahedral carbon, and in general a geometric view of matter, was pioneered by other chemists, Van’t Hoff and Le Bel used this idea to solve the puzzle of optical activity, thereby establishing a direct linkage between structure and physical properties. It is also interesting to note that (...) their proposals came without experimental verification and they were largely based on experiments conducted by others. Philosophical arguments can, however, be invoked to satisfactorily validate this deductive reasoning. (shrink)

This paper investigates the interface between philosophy and biochemistry. While it is problematic to justify the application of a particular philosophical model to biochemistry, it seems to be even more difficult to develop a special “Philosophy for Biochemistry”. Alternatively, philosophy can be used in biochemistry based on an alternative approach that involves an interdependent iteration process at a philosophical and (bio)chemical level (“Exeter Method”). This useful iteration method supplements more abstract approaches at the interface between philosophy and natural sciences, and (...) serves the biochemical community to systematically locate logical inconsistencies that arise from more theoretical aspects of the scientific process. Initial cycles of this iteration process identify the in vitro–in vivo problem as a central epistemological difficulty in biochemical research. While previous attempts have generated ad hoc rules to mend the gap between chemistry, biochemistry and biology in order to justify in vitro experimentation, this paper concludes that in vitro experimentation is heavily based on chemistry and cannot derive definite statements about biological processes. It can, however, generate results that will influence the direction of future biological research. The consequence is that the relationship between in vitro and in vivo experimentation is more of a psychological or social one than of a logical nature. Apart from highlighting these inconsistencies in biochemical thinking (“problem awareness”), the Exeter Method demands an improvement of biochemical terminology that contains separate and unequivocally defined terms for in vitro and in vivo systems. (shrink)

Traditional philosophy of science regards theoretical reasoning, based on the example of Euclidian geometry, as the hallmark of a mature science. There is, however, a parallel tradition of practical reasoning based on specific cases that goes back to Aristotle. In this paper I argue that practical reasoning is an essential part of the practice of chemistry and should be understood and appreciated on its own merits rather than regarded as a symbol of the immaturity and inferiority of chemistry as a (...) science. (shrink)

The problem of the peculiarcharacter of chemical laws and theories is a central topic in philosophy of chemistry. Oneof the most characteristic and, at the sametime, most puzzling examples in discussions onchemical laws and theories is Mendeleev''speriodic law. This law seems to be essentiallydifferent in its nature from the exact laws ofclassical physics, the latter being usuallyregarded as a paradigm of science byphilosophers. In this paper the main argumentsconcerning the peculiar character of chemicallaws and theories are examined. The laws ofchemistry (...) are natural laws to the same extentas are the laws of physics. The law discoveredby Mendeleev is a normal law of nature. It isnot a law of physics, nevertheless, it is exactin the same philosophical sense as are the lawsof physics. The periodic system of chemicalelements was established by constructing anidealized system of idealized elements. Thefundamental idealization substantiated byexperimental chemistry was the chemicalelement as a place in the periodicsystem. (shrink)

While the principal ideas of a systems theory for the molecular sciences have been introduced in part I (Reiher, 2003), illustrative examples for the ingredients of this systems chemistry are discussed in greater detail in this work. The potential wealth of systems chemistry is then demonstrated for a recently developed approach for the calculation of hydrogen bond energies in non-decomposable systems.

A recent article by Vihalemm (Foundations of Chemistry, 2003) is critical of an earlier essay. We find that there is some justification for his criticism of vagueness in defining terms. Nevertheless the main conclusions of the earlier work, when carefully restated to deflect Vihalemm’s criticisms, are unaffected by his arguments. The various dicta that are used as the bases of chemical explanations are different in character, and are used in a different way from the laws and theories in classical physics.

This essay addresses issues concerningexplanation by exploring how explanatorystructures function within contemporarychemistry. Three examples are discussed:explanations of the behavior of gases using theideal gas law, explanations of trends inchemical properties using the periodic table,and explanations of molecular geometry usingdiagrammatic orbital schemes. In each case,the general explanatory structure, rather thanparticular explanations, occupies center stagein the analysis. It is argued that thisquasi-empirical investigation may be morefruitful than previous analyses that attempt toisolate the essential features of individualexplanations. There are two reasons for thisconclusion, (...) each discussed in some detail. First, the traditional analyses rely on highlyprecarious reasoning. Second, empiricallygrounded investigations provide a more naturalconnection to the core aim of analyses ofexplanation, namely to provide a rationale forthe widely expressed preference for explanatorytheories in science. (shrink)

Most contemporary chemists consider quantum mechanics to be the foundational theory of their discipline, although few of the calculations that a strict reduction would seem to require have ever been produced. In this essay I discuss contemporary algebraic and diagrammatic representations of molecular systems derived from quantum mechanical models, specifically configuration interaction wavefunctions for ab initio calculations and molecular orbital energy diagrams. My aim is to suggest that recent dissatisfaction with reductive accounts of chemical theory may stem from both the (...) inability of standard accounts of reduction to incorporate the diverse forms of representation found in chemical practice and our philosophical predilection to analyze all connections between theories in terms of logical reduction. (shrink)

In contrast to the conventional homogeneous kinetics, there is no conception of a simple reaction in the solid-state reaction kinetics. The geometric-probabilistic phenomenology currently in use is not adequate for describing the interplay between the chemical mechanism and the observed kinetic behaviour. An attempt is made to formulate a conception of simple reaction in the solid state as a basis for constructing kinetic models of involved reactions.

In the philosophy of chemistry a view is developed according to which laws of nature and scientific theories are peculiar in chemistry. This view was criticized in an earlier issue of the Foundations of Chemistry (Vihalemm, Foundation of Chemistry 5(1): 7–22, 2003) referring to an essay by Maureen and John Christie (Christie and Christie, in N. Bushan and S. Rosenfeld (Eds.), Of Minds and Molecules: New Philosophical Perspectives on Chemistry. Oxford University Press, New York, 2000, pp. 34–50). This criticism was (...) responded by the Christies (Christie and Christie, Foundations of Chemistry 5(2): 165–177, 2003). In the present article the debate is continued. The main issues which need to be elucidated in order to carry the analysis forward are pointed out and discussed. The relevance of a theoretical model of science for the philosophy of chemistry is stressed. (shrink)

Traditional nomological accounts of scientific explanation have assumed that a good scientific explanation consists in the derivation of the explanandum’s description from theory (plus antecedent conditions). But in more recent philosophy of science the adequacy of this approach has been challenged, because the relation between theory and phenomena in actual scientific practice turns out to be more intricate. This critique is here examined for an explanatory paradigm that was groundbreaking for 20th century physics and chemistry (and their interrelation): Bohr’s first (...) model of the atom and its explanatory relevance for the spectrum of hydrogen. First, the model itself is analysed with respect to the principles and assumptions that enter into its premises. Thereafter, the origin of the model’s explanandum is investigated. It can be shown that the explained “phenomenon” is itself the product of a host of modelling accomplishments that stem from an experimental tradition related to 19th century chemistry, viz. spectroscopy. The relation between theory and phenomenon is thus mediated in a twofold way: by (Bohr’s) theoretical model and a phenomenological model from spectroscopy. In the final section of the paper an account is outlined that nevertheless permits us to acknowledge this important physico-chemical achievement as a case of (nomological) explanation. (shrink)

Enzymes are protein catalysts of extraordinary efficiency, capable of bringing about rate enhancements of their biochemical reactions that can approach factors of 1020. Theories of enzyme catalysis, which seek to explain the means by which enzymes effect catalytic transformation of the substrate molecules on which they work, have evolved over the past century from the “lock-and-key” model proposed by Emil Fischer in 1894 to models that explicitly rely on transition state theory to the most recent theories that strive to provide (...) accounts that stress the essential role of protein dynamics. In this paper, I attempt to construct a metaphysical framework within which these new models of enzyme catalysis can be developed. This framework is constructed from key doctrines of process thought, which gives ontologic priority to becoming over being, as well as tenets of a process philosophy of chemistry, which stresses environmentally responsive molecular transformation. Enzyme catalysis can now be seen not as enzyme acting on its substrate, but rather as enzyme and substrate entering into a relation which allows them to traverse the reaction coordinate as an ontologic unity. (shrink)

Thought experiments in the history of science display a striking asymmetry between chemistry and physics, namely that chemistry seems to lack well-known examples, whereas physics presents many famous examples. This asymmetry, I argue, is not independent data concerning the chemistry/physics distinction. The laws of chemistry such as the periodic table are incurably special, in that they make testable predictions only for a very restricted range of physical conditions in the universe which are necessarily conditioned by the contingences of chemical investigation. (...) The argument depends on how ‚thought experiment’ is construed. Here, several recent accounts of thought experiments are surveyed to help formulate what I call ‚crucial’ thought experiments. These have a historical role in helping to judge between hypotheses in physics, but are not helpful in chemistry past or present. (shrink)

This is the second of a series of essays on the development and reception of Wilhelm Ostwald’s energetics. The first essay described the chemical origins of Ostwald’s interest in the energy concept and his motivations for seeking a comprehensive science of energy. The present essay and the next discuss his various attempts, beginning in 1891 and extending over almost 3 years, to develop a consistent and coherent energetic theory. A final essay will consider reactions to this work and Ostwald’s replies, (...) and will also seek to evaluate his program of research. Ostwald’s project – to reconstruct physics and chemistry “as a pure energetics” – is worth attending to for several reasons: first, because Ostwald did ground-breaking work in chemistry (he was awarded a Nobel Prize in 1909 for his studies in catalysis and rates of reaction); second, because an important school of physical chemistry formed around him at Leipzig, a school that promoted his ideas; and, finally, because he was a prominent and vigorous participant in debates at the end of the nineteenth century concerning the proper course of physical theory. (shrink)

In this paper, domain-specificity is presented as an understudied problem in chemical education. This argument is unpacked by drawing from two bodies of literature: learning of science and epistemology of science, both themes that have cognitive as well as philosophical undertones. The wider context is students’ engagement in scientific inquiry, an important goal for science education and one that has not been well executed in everyday classrooms. The focus on science learning illustrates the role of domain specificity in scientific reasoning. (...) The discussion on epistemology of science presents ideas from the emerging field of philosophy of chemistry to highlight the much neglected area of epistemology in chemical education. Domain-specificity is exemplified in the context of chemical laws, in particular the Periodic Law. The applications of the discussion for chemical education are explored in relation to argumentation, itself an epistemologically grounded discourse pattern in science. The overall implications include the need for reconceptualization of the nature of teaching and learning in chemistry to include more particular epistemological aspects of chemistry. (shrink)

Similarities in properties among pairs of metallic elements and their compounds in the lower-right quadrant of the Periodic Table have been named the ‘Knight’s Move’ relationship. Here, we have undertaken a systematic study of the only two ‘double-pairs’ of ‘Knight’s Move’ elements within this region: copper-indium/indium-bismuth and zinc-tin/tin-polonium, focussing on: metal melting points; formulas and properties of compounds; and melting points of halides and chalcogenides. On the basis of these comparisons, we conclude that the systematic evidence for ‘Knight’s Move’ relationships (...) derives from similarities in formulas and properties of matching pairs of compounds in the same oxidation state. Physical properties, such as melting points, do not provide consistent patterns and trends and hence should not be considered as a common characteristic of this relationship. (shrink)

Eric Scerri and other authors have acknowledged that the reality of chemical orbitals is not compatible with quantum mechanics. Recently, however, Scerri and Sharon Crasnow have argued that if chemists cannot consider orbitals as real entities, then chemistry is in danger of being reduced to physics. I argue that the question of the existence of orbitals is best viewed as an issue of explanation, not metaphysics: In many chemically important cases orbitals do not make sufficiently accurate predictions, and must be (...) replaced. Chemists and physicists can acknowledge this fact while maintaining the utility of orbitals and the autonomy of chemistry. (shrink)

Many theories require empirical patches or ad hoc assumptions to work properly in application to chemistry. Some examples include the Bohr quantum theory of atomic spectra, the Pauli exclusion principle, the Marcus theory of the rate-equilibrium correlation, Kekule’s hypothesis of bond oscillation in benzene, and the quantum calculation of reaction pathways. Often the proposed refinements do not grow out of the original theory but are devised and added ad hoc. This brings into question the goal of constructing theories derived from (...) first principles and the concept of ranking the merit of theories according to their freedom from empirical contamination. (shrink)

This is the third of a series of essays on the development and reception of Wilhelm Ostwald’s energetics. The first essay described the chemical origins of Ostwald’s interest in the energy concept and his motivations for seeking a comprehensive science of energy. The second essay and the present one discuss his various attempts, beginning in 1891 and extending over almost 3 years, to develop a consistent and coherent energetic theory. A final essay will consider reactions to this work and Ostwald’s (...) replies, and will also seek to evaluate his program of research. Ostwald’s project—to reconstruct physics and chemistry “as a pure energetics”—is worth attending to for several reasons: first, because Ostwald did ground-breaking work in chemistry (he was awarded a Nobel Prize in 1909 for his studies in catalysis and rates of reaction); second, because an important school of physical chemistry formed around him at Leipzig, a school that promoted his ideas; and, finally, because he was a prominent and vigorous participant in debates at the end of the nineteenth century concerning the proper course of physical theory. (shrink)

The project of chemistry to classify substances and develop techniques for their transformation into other substances rests on assumptions about the means by which compounds are constituted and reconstituted. Robert Boyle not only proposed empirical tests for a metaphysics of material corpuscules, but also a principle for designing experimental procedures in line with that metaphysics. Later chemists added activity concepts to the repertoire. The logic of activity explanations in modern times involves hierarchies of activity concepts, transitions between levels through non-dispositional (...) groundings. Such hierarchies terminate in powerful particulars, such as elementary charged particles. Do these have a fundamental place in the most recent accounts of molecular architecture, stabilities and transformations? However, a close study of the contemporary chemistry of substances transforming reactions discloses a hybrid metaphysics, making use of both the Boylean corpuscles and Faradayan fields. This is illustrated by an analysis of the metaphysics inherent in John Polanyi’s use of “chemoluminescence” to follow the formation of products in chemical reactions. A brief sketch of a resolution of the tension between the two metaphysical schemes is drawn from Niels Bohr’s radical metaphysics extended from the quantum realm proper to chemistry (and perhaps beyond). (shrink)

In this paper I investigate two views of theoretical explanation in quantum chemistry, advocated by John Clarke Slater and Charles Coulson. Slater argued for quantum‐mechanical rigor, and the primacy of fundamental principles in models of chemical bonding. Coulson emphasized systematic explanatory power within chemistry, and continuity with existing chemical explanations. I relate these views to the epistemic contexts of their disciplines.

Although chemical phenomena are primarily associated with electrons in atoms, ions, and molecules, the masses, charges, spins, and other properties of the nuclei in these species contribute significantly as well. Isotopes, for instance, have proven invaluable in chemistry, in particular the elucidation of reaction mechanisms. Elements with unstable nuclei, for example carbon-14 undergoing beta decay, have enriched chemistry and many other scientific disciplines. The nuclei of all elements have a much more subtle and largely unknown effect on chemical phenomena. All (...) nuclei are innately chiral and, because electrons can penetrate nuclei, all atoms and molecules are likewise chiral. This article describes in considerable detail the discovery of chiral nuclei, how this unusual chirality may influence the chemical behavior of atoms and molecules, and how atomic chirality may have been responsible for the synthesis of optically active molecules in the pre-biotic world. (shrink)

The usefulness of isoelectronic series (same number of total electrons and atoms and of valence electrons) across Periods is often overlooked. Here we show the ubiquitousness of isoelectronic sets by means of matrices, arrays, and sequential series. Some of these series have not previously been identified. In addition, we recommend the use of the term valence-isoelectronic for species which differ in the number of core electrons and pseudo-isoelectronic for matching (n) and (n + 10) species.

In the last years there has been a great improvement in the development of computational methods for combinatorial chemistry applied to drug discovery. This approach to drug discovery is sometimes called a “rational way” to manage a well known phenomenon in chemistry: serendipity discoveries. Traditionally, serendipity discoveries are understood as accidental findings made when the discoverer is in quest for something else. This ‘traditional’ pattern of serendipity appears to be a good characterization of discoveries where “luck” plays a key role. (...) In this sense, some initial failures in combinatorial chemistry are frequently attributed to a naïf appropriation of a “serendipity model” for discovery (a “serendipity mistake”). In this paper we try to evaluate this statement by criticizing its foundations. It will be suggested that the notion of serendipity has different aspects and that the criticism to the first attempts could be understood as a “serendipity mistake.” We will suggest that “serendipity” strategies, a kind of blind search, can be seen sometimes as a “genuine part” of scientific practice. A discussion will ensue about how this characterization can give us a better understanding of some aspects of serendipity discoveries. (shrink)

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. (shrink)