Paneth, Kant, and the philosophy of chemistry

Immanuel Kant has built up a dualistic epistemology that seems to fit to the peculiarities of chemistry quite well. Friedrich Paneth used Kant’s concept and characterised simple and basic substances which refer to the empirical and to the transcendental world, respectively. This paper takes account of the Kantian influences in Paneth’s philosophy of chemistry, and discusses pertinent topics, like observables, atomism and realism.

Hermann Jahn and Rudolf Renner of the Jahn–Teller and Renner–Teller effects

Vibronic interactions have received increasing attention in modern structural chemistry. Edward Teller played a pioneering role in understanding and describing them during the “molecular physics” period of his scientific career. Very little is known about the two scientists who contributed significantly to our knowledge about these effects and whose names have become associated with Teller’s. This Editorial is devoted to Hermann Jahn and Rudolf Renner and attempts to lift them out of oblivion by paying them tribute for their contributions.

A novel Ce<Superscript>III</Superscript>-cyclam type complex and its redox chemistry in aqueous solutions

A new Ce^III complex was synthesized by mixing the ligand “dioxocyclam” with Ce^III ions at pH 8.0 and its redox properties were investigated.

The meaning of ‘concentration’

Terminology within a small laboratory community can be informal without danger of misunderstanding, but communication with a wider audience and not least in publications, needs unequivocal terms for defined concepts. As an example, the many meanings of “concentration” are explored to present a systematic nomenclature, including a concept diagram.

A note on Michael Weisberg’s: challenges to the structural conception of chemical bonding

Michael Weisberg’s recent 2007 paper on the chemical bond makes the claim that the chemical notion of the covalent bond is in trouble. This note casts doubts on that claim.

Pt–Ru electrocatalysts for fuel cells: a representative review

Three periods of Pt–Ru research are considered step-by-step: the initial period after discovery (1963–1970); observation and classification of basic tendencies (like the effects of composition, segregation, structural features on the activity; up to 1990); nanostructural studies and molecular level consideration of electrocatalytic phenomena in combination with advanced applied studies of materials, mechanistic, and applied aspects (after 1990). The main idea of this review is to balance various aspects of Pt–Ru electrochemistry related to material science and electrocatalysis as well as to remember the early basic results being of importance for future understanding of Pt–Ru functional properties. Dedicated to Professor Teresa Iwasita, as a token of her remarkable contribution to electrocatalysis.

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Encapsulating of single quantum dots into polymer particles

Single semiconductor quantum dots were embedded into polymer particles with diameters below 0.1 μm by an emulsion polymerization procedure or via a secondary dispersion approach. The photoluminescence properties of the nanocrystals are retained upon encapsulation, as demonstrated by fluorescence confocal microscopy.

Vocabulary of terms in protometrology

Protometrology is a new term recently proposed to designate the science of observation. As any field of knowledge needs a terminological system, in this article a system of terms and definitions on protometrology, with examples belonging to clinical laboratory sciences, is presented. This terminological system starts with the definitions of the two primitive concepts “object” and “property”.

The chemist’s concept of molecular structure

The concept of molecular structure is fundamental to the practice and understanding of chemistry, but the meaning of this term has evolved and is still evolving. The Born–Oppenheimer separation of electronic and nuclear motions lies at the heart of most modern quantum chemical models of molecular structure. While this separation introduces a great computational and practical simplification, it is neither essential to the conceptual formulation of molecular structure nor universally valid. Going beyond the Born–Oppenheimer approximation introduces new paradigms, bringing fresh insight into the chemistry of fluxional molecules, proteins, superconductors and macroscopic dielectrics, thus opening up new avenues for exploration. But it requires that our ideas of molecular structure need to evolve beyond simple ball-and-stick-type models.

Chemical supervenience

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.

Atom and aether in nineteenth-century physical science

This paper suggests that the cases made for atoms and the aether in nineteenth-century physical science were analogous, with the implication that the case for the atom was less than compelling, since there is no aether. It is argued that atoms did not play a productive role in nineteenth-century chemistry any more than the aether did in physics. Atoms and molecules did eventually find an indispensable home in chemistry but by the time that they did so they were different kinds of entities to those figuring in the speculations of those natural philosophers who were atomists. Advances in nineteenth-century chemistry were a precondition for rather than the result of the productive introduction of atoms into chemistry.

Preparation, structural, and optical features of two-dimensional cross-linked DNA/gold-nanoparticle conjugates

The formation and the optical features of two-dimensional aggregates formed by DNA-directed immobilization and cross-linking of bifunctional DNA–gold nanoparticles at flat gold substrates are analyzed. The samples are structurally characterized by atomic force microscopy to evaluate the particle size, the particle densities, and the degree of aggregation. The optical characteristics determined by UV/visible measurements are correlated with the structural features observed.

Wilhelm Ostwald’s energetics 3: energetic theory and applications,part II

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.

Hydrogen evolution and oxidation—a prototype for an electrocatalytic reaction

Due to progress in the theory of electrocatalysis and in quantum chemistry, it has become possible to investigate the hydrogen reaction and perform quantitative calculations for the reaction rate. First, we demonstrate this with model calculations for the adsorption of hydrogen on Pt(111). In accordance with experimental data, we find hydrogen adsorption at a potential above the equilibrium potential and with an almost vanishing energy of activation. As a second example, we explain trends in the catalytic activity of palladium overlayers and clusters on Au(111) electrodes. Dedicated to J.O’M. Bockris on the occasion of his 85th birthday and in recognition of his contributions to electrochemistry.

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Update on COMAR: the Internet database for certified reference materials

This paper describes the COMAR database for certified reference materials (CRMs). The Web-based version of COMAR is freely accessible via the Internet. COMAR was established to assist laboratories in finding the CRMs needed. The database is maintained in a collaboration of the world’s major CRM producers. The planned changes in the database as agreed at the last COMAR council meeting in Prague in May 2006 are indicated.

Do we need to rethink collaborative trials?

The currently recommended design of collaborative trials (interlaboratory method performance studies) is examined in relation to the usefulness of the resulting statistics. It is suggested that larger experiments, without duplicate analysis, would be more informative.

Structure and chromotropic properties of mono- and binuclear mixed-ligand nickel(II) complexes containing 1,3-diketonate and polyamine ligands

Abstract  Mixed-ligand Ni^II complexes have been synthesized with 1,3-diketonate and bulky tri- or tetra-amine ligands. Their structures were determined by X-ray crystallography, and solvatochromic behavior was examined by UV–vis–NIR spectroscopy. Steric effects of the bulky ligands on the coordination distances and spectral properties are discussed. Graphical Abstract  

Structural formulas and explanation in organic chemistry

Organic chemists have been able to develop a robust, theoretical understanding of the phenomena they study; however, the primary theoretical devices employed in this field are not mathematical equations or laws, as is the case in most other physical sciences. Instead it is diagrams, and in particular structural formulas and potential energy diagrams, that carry the explanatory weight in the discipline. To understand how this is so, it is necessary to investigate both the nature of the diagrams employed in organic chemistry and how these diagrams are used in the explanations of the discipline. I will begin this paper by characterizing some of the major ways that structural formulas used in organic chemistry. Next I will present a model of the explanations in organic chemistry and describe how both structural formulas and potential energy diagrams contribute to these explanations. This will be followed by several examples that support my abstract account of the role of diagrams in the explanations of organic chemistry. In particular, I will consider both the appeal to ‘hyperconjugation’ in the explanation of alkene stability and how the idea of ‘ring strain’ was developed to explain the relative stability of cyclic compounds.

Metrological traceability: I make it 42; you make it 42; but is it the same 42?

The paper reproduces a talk given at a 2-day symposium on quality assurance in chemistry held in Brisbane, Australia in 2005. Intended for an audience of analysts in the field, the theme of the symposium drew inspiration from the series of books by Douglas Adams “The Hitchhiker's Guide to the Galaxy”. An introduction to basic concepts of metrological traceability is followed by a discussion of practical steps to ensure metrological traceability of field measurement results. The relationship between metrological traceability and comparability of measurement results is discussed. To achieve metrological traceability in the field, the use of appropriate certified reference materials for calibration is recommended. Examples of atmospheric carbon dioxide and roadside breathalyzer measurements are given.

Why take chemistry stoically? The case of Posidonius

This paper analyzes views of the Stoic philosopher Posidonius (1st century BC) in the light of modern Chemistry. I propose that Posidonius’ account on “generation and destruction” bears noteworthy similarities to the scientific notions of chemical elements, chemical species, nuclear reactions, and the law of conservation of mass. I find that his views compare favorably also with our understanding of chemical change at solid surfaces. Provided his thought is correctly placed in the cultural context of his day, I argue that Posidonius deserves a previously un-acknowledged consideration in the historical background of modern Chemistry.