Robert Boyle’s Knowledge of Spain and his Citations of Spanish Authors

Robert Boyles knowledge of Spain was gained from three sources; his visitors, his correspondents and from reading texts by Spanish authors. A summary is presented of the items of Spanish interest in his correspondence and in his published works.     

Alchemy,Prophecy, and Politics in Eighteenth-Century Iberia: Anselmo Castelo Branco's Critique of Benito Feijoo

The Benedictine monk Benito Jerónimo Feijoo (1676–1764) is now considered one of the major figures of the Spanish and Iberian Enlightenment. However his work, both in Spain and in Portugal, was far from being universally acclaimed. His critical approach to the subject of alchemy in his essay “Piedra Filosofal,” published in the third volume of his magisterial Teatro Crítico Universal (1726–1739), sparked an unexpected response from the Portuguese alchemist Anselmo Castelo Branco, who sought to refute Feijoo's claims in his own work, the Ennoea. This paper presents an outline of this exchange and its position within Iberian Enlightenment circles. It further argues that Castelo Branco's defence of alchemy was informed by his political and prophetic views, in particular his adherence to the Portuguese messianic doctrine of Sebastianism.     

A novel heterogeneous acid-activated clay supported copper catalyst for the photobleaching and degradation of textile organic pollutant using photo-Fenton-like reaction

Copper supported on acid-activated bentonite clay was found to be an effective catalyst for the photo degradation of Acid Black 1 at pH 3.0-8.0 without significant metal leaching.     

Ion-chromatography of metals with post-column ion displacement

A post-column reagent mixture of Eriochrome Black T and magnesium-EDTA complex is added to the eluent from an ion-chromatograph. Eluted metal cations displace the magnesium, which then forms a complex with the Eriochrome Black T. The absorbance of this complex is measured at 520 nm. Detection limits for several cations are in the mug/ml range.     

Boerhaave to Black: the Evolution of Chemistry Teaching

Abstract

Hermann Boerhaave (1668–1738) at Leiden and Joseph Black (1728–1799) at Edinburgh were known in the eighteenth-century medical world as inspirational and transforming teachers of chemistry. A critical examination of the content of their courses indicates how the idea and uses of chemistry changed through that century. Boerhaave's chemistry was closely allied to the need for training doctors in the materia medica, while for Black, chemistry had become more detached from medicine and could be of industrial relevance and, thereby, of economic benefit. Most of those attending his lectures would not end up as physicians. Both Black and Boerhaave had strongly held views of their pedagogical responsibilities, and neither had aspirations to develop research schools: that idea had to wait until later.     

Charles J. Pedersen: innovator in macrocyclic chemistry and co-recipient of the 1987 Nobel Prize in chemistry

Charles J. Pedersen began life in Korea where his father was employed as an engineer at a gold mine in a remote region of that country. He received his primary and secondary school education in Japan and university training in the United States. He was employed as an organic research chemist at DuPont for 42 years. The signal accomplishment of this unusual individual was his serendipitous discovery of macrocyclic polyethers and of their selective complexation of alkali metal cations. This discovery sparked the development of a new field of chemistry and led to his sharing the Nobel Prize in Chemistry in 1987. An attempt is made to understand Pedersen as a person in this article.     

An instrumental neutron activation analysis of 18th century lead-glazed earthenwares from four Spanish missions in Texas

Instrumental Neutron Activation Analysis (INAA) was used to determine relative manufacturing locales of lead-glazed earthenwares recovered from four Spanish missions in Texas. Two principal clays were distinguished, one containing volcanic ash and one sand. The ceramics characterized by the volcanic ash were believed to have been manufactured in Mexico, while those containing sand were made in Texas. This distinctionis important because it suggests that the Indians at the Texas missions were manufacturing ceramics using Spanish technology such as lead-glazing.     

Designing new metal affinity peptides by random mutagenesis of a natural metal-binding site

The metal-binding site of a Helicobacter pylori ATPase 439 (heli(WT)-tag) was successfully used as a new fusion peptide for immobilized metal ion affinity chromatography (IMAC). It produced higher yields than the frequently used his6-tag. Due to stronger binding of the peptide to metal ions, harsher elution conditions were, however, necessary. This undesired side-effect was overcome by modifying the heli(WT)-tag by polymerase chain reaction-directed mutagenesis. The modified tags were screened by an automated high-throughput IMAC system, leading to a heliM14-tag peptide that could be eluted under conditions similar to those of the his6-tag but at the same time produced 20% higher yields of the desired protein.     

Paracelsus,a Transmutational Alchemist

A scholarly consensus has long held that in redefining alchemy, Paracelsus rejected metallic transmutation. I show here, however, that for most of his career Paracelsus believed that it was possible to change one metal into another, and even late in his short life he did not break with that view. Furthermore, in certain places in his works he also represented himself, occasionally directly and more often obliquely, as a practical transmutationist. Because Paracelsus not only acknowledged that metallic transmutations were theoretically possible but also claimed to have carried them out in practice, we must regard him as (among other things) a transmutational alchemist. As such, he had more in common than historians have generally admitted with both his medieval predecessors and his posthumous followers. The Paracelsian alchemists of the late-sixteenth and seventeenth centuries were not wrong to situate Paracelsus within the alchemical tradition, nor to connect their own goldmaking interests to his.     

多吡唑烷配合物研究进展

描述了双吡唑烷及其三吡唑甲烷配体的合成,详细地综述了它们在无机配位化学及金属有机等方面近年来的研究进展。     

Heavy metal and trace element accumulation in muscle,liver and gills of the Pontic shad (Alosa immaculata Bennet 1835) from the Danube River (Serbia)

Pontic shad (Alosa immaculata Bennet 1835) is an anadromous species that lives in the heavily polluted north-western part of the Black Sea and migrates into the Danube River to spawn. To assess their heavy metal contamination levels, samples of Pontic shad were collected at 863 river kilometre of the Danube River. Muscle, liver and gill samples were prepared using microwave digestion, and the analysis of Al, As, Cd, Cu, B, Ba, Fe, Mg, Sr, Zn, Li, Co, Cr, Mn, Mo, Ni and Pb was performed with inductively-coupled plasma-optic emission spectroscopy (ICP-OES). Significant differences in concentrations of analyzed elements were observed among different tissues, as well as between the genders. Al, Sr, Ba, Mg, and Li had the highest concentrations in gills, while Cd, Cu, Zn, Fe and B were highest in the liver. While the muscle had the lowest concentrations of most of the analyzed elements, it had the highest concentration of As. This study has revealed that the concentrations of Cd and As in Pontic shad muscle tissue were above the maximum acceptable concentrations for human consumption, thus precautions need to be taken in order to prevent future heavy metal contamination.     

Choline Chloride Assisted Synthesis of N and Metal Codoped TiO2 and their Photocatalytic Activity under Visible Light

A few nanocrystalline N,metal codoped TiO₂ (metal = Cr, Mn, Fe, Co, Ni, Cu and Zn) have been synthesized by a simple sol–gel method using choline chloride which is biodegradable, low cost, nontoxic ionic salt both as a structure directing agent and source of nitrogen. The prepared samples were well characterized by XRD, HRTEM, FTIR, DRS, EDX, XPS and BET techniques. The photocatalytic activity of all synthesized N, metal codoped TiO₂ has been carried out for the degradation of Reactive Black 5 dye under visible light irradiation and among them, N, Fe codoped TiO₂ was found to be the best for the degradation of Reactive Black 5 dye. The effect of incorporated metals on the photocatalytic activity of the various modified TiO₂ has been discussed in detail based on the mechanism involved in the degradation of dye and their physico‐chemical properties which includes surface area, particle size, defect sites, phase, band gap and electron–hole recombination effect.     

Monitoring of Fe,Mn, Cu,Pb and Cd levels in two brown macroalgae from the Bulgarian Black Sea coast

Heavy metal contents (Fe, Mn, Cu, Pb and Cd) were determined in two brown macroalgal species (Cystoseira crinita and Cystoseira barbata). Samples were collected during six seasons from spring 1996 to summer 2000 from five different sites of the Bulgarian Black Sea coastal zone – Tuzlata, Ravda, Sozopol, Ahtopol and Sinemoretz. The local and seasonal metal distribution and their variations were examined.

The data obtained indicate that the two investigated species demonstrate various degrees of metal accumulation and can be used as indicators for the type and quantity of anthropogenic contamination in marine ecosystems.     

Ruthenium-based electrocatalysts for oxygen reduction reaction—a review

A major impediment to the commercialization of fuel cells is the low activity of electrocatalysts for the oxygen reduction reaction that involves multiple electron transfer steps. Platinum is considered the best cathode catalyst toward oxygen reduction to water; however, Pt remains an expensive metal of low abundance, and it is of great importance to find Pt-free metal alternatives. Among various Pt-free catalysts under development, ruthenium-based compounds show significant catalytic activity and selectivity for four-electron reduction of oxygen to water in acidic environments. This article provides a short review on the different classes of Ru-based catalysts focusing on the catalytically active reaction sites and the oxygen reduction mechanism in acidic media. After a brief discussion of the oxygen reduction kinetics on a pure Ru metal, the paper reviews the catalytic properties of the selected Ru compounds, including crystalline Chevrel-phase chalcogenides, nanostructured Ru and Ru–Se clusters, and Ru–N chelate compounds. This paper is dedicated to Professor Su-Il Pyun, who has pioneered advances in interfacial electrochemistry in the field of corrosion and materials science in South Korea, on the occasion of his 65th birthday.     

Reaction Chemistry at Discrete Organometallic Fragments on Black Phosphorus

Black phosphorus (bP) is a two-dimensional van der Waals material unique in its potential to serve as a support for single-site catalysts due to its similarity to molecular phosphines, ligands quintessential in homogeneous catalysis. However, there is a scarcity of synthetic methods to install single metal centers on the bP lattice. Here, we demonstrate the functionalization of bP nanosheets with molecular Re and Mo complexes. A suite of characterization techniques, including infrared, X-ray photoelectron and X-ray absorption spectroscopy as well as scanning transmission electron microscopy corroborate that the functionalized nanosheets contain a high density of discrete metal centers directly bound to the bP surface. Moreover, the supported metal centers are chemically accessible and can undergo ligand exchange transformations without detaching from the surface. The steric and electronic properties of bP as a ligand are estimated with respect to molecular phosphines. Sterically, bP resembles tri(tolyl)phosphine when monodentate to a metal center, and bis(diphenylphosphino)propane when bidentate, whereas electronically bP is a σ-donor as strong as a trialkyl phosphine. This work is foundational in elucidating the nature of black phosphorus as a ligand and underscores the viability of using bP as a basis for single-site catalysts.     

Tritium activity concentration along the Western shore of the Black Sea

The Black Sea tritium level was investigated in 33 places southward the Danube Delta covering about 360 km of the Black Sea Western Shore. Both surface (10 cm depth) and bottom (up to 20 m depth) water samples were collected. In the close vicinity of Danube Delta, the tritium activity concentration in the surface water was around 28 TU, which is almost the same as that of the Danube River waters, but it decreased to about 5 TU in the bottom water. This discrepancy slowly diminished wherein at about 120 km southward, the tritium content in both surface and bottom water reached almost the same constant value of 6.5 ± 2.3 TU. This value, about two and a half times smaller than that reported 17 years ago, remained almost unchanged for the last 240 km of shore up to the Turkish border.     

The Cytotoxicity of Layered Black Phosphorus

Black phosphorus (BP), the latest addition to the family of 2D layered materials, has attracted much interest owing to potential optoelectronics, nanoelectronics, and biomedicine applications. Little is known about its toxicity, such as whether it could be as toxic as white phosphorus. In response to the possibility of BP employment into commercial products and biomedical devices, its cytotoxicity to human lung carcinoma epithelial cells (A549) was investigated. Following a 24 h exposure of the cells with different BP concentrations, cell viability assessments were conducted using water‐soluble tetrazolium salt (WST‐8) and methylthiazolyldiphenyltetrazolium bromide (MTT) assays. The toxicological effects were found to be dose‐dependent, with BP reducing cell viabilities to 48 % (WST‐8) and 34 % (MTT) at 50 μg mL^?1 exposure. This toxicity was observed to be generally intermediate between that of graphene oxides and exfoliated transition‐metal dichalcogenides (MoS₂, WS₂, WSe₂). The relatively low toxicity paves the way to utilization of black phosphorus.     

Metal–Metal Bond in the Light of Pauling’s Rules

About 70 years ago, in the framework of his theory of chemical bonding, Pauling proposed an empirical correlation between the bond valences (or effective bond orders (BOs)) and the bond lengths. Till now, this simple correlation, basic in the bond valence model (BVM), is widely used in crystal chemistry, but it was considered irrelevant for metal–metal bonds. An extensive analysis of the quantum chemistry data computed in the last years confirms very well the validity of Pauling’s correlation for both localized and delocalized interactions. This paper briefly summarizes advances in the application of the BVM for compounds with TM–TM bonds (TM = transition metal) and provides further convincing examples. In particular, the BVM model allows for very simple but precise calculations of the effective BOs of the TM–TM interactions. Based on the comparison between formal and effective BOs, we can easily describe steric and electrostatic effects. A possible influence of these effects on materials stability is discussed.     

Humphry Davy and the Problem of Analogy

Analogy, the comparison of one set of relations to another, was essential to Humphry Davy’s understanding of chemistry. Throughout his career, Davy used analogical reasoning to direct and to interpret his experimental analyses of the chemical reactions between substances. In his writing, he deployed analogies to organise and to explain his theories about the relations between physical processes and between the properties of different chemical elements and compounds. But Davy also regularly expressed two concerns about analogical comparison: first, that it was founded not on the rational interpretation of facts but on imaginative speculation; and second, that it was a kind of rhetoric, the persuasiveness of which depended not on material evidence but on misleading figures of speech. This article discusses the influences that informed Davy’s ambivalent assessment of the value of analogy, and it examines the distinct yet overlapping ways in which this assessment was expressed in his notebooks, his lectures and treatises on chemistry, his philosophical writings, and his poetry.     

Bridging the Gap: From Homogeneous to Heterogeneous Parahydrogen-induced Hyperpolarization and Beyond

Demonstration of parahydrogen-induced polarization effects in hydrogenations catalyzed by heterogeneous catalysts instead of metal complexes in a homogeneous solution has opened an entirely new dimension for parahydrogen-based research, demonstrating its applicability not only for the production of catalyst-free hyperpolarized liquids and gases and long-lived non-equilibrium spin states for potential biomedical applications, but also for addressing challenges of modern fundamental and industrial catalysis including advanced mechanistic studies of catalytic reactions and operando NMR and MRI of reactors. This essay summarizes the progress achieved in this field by highlighting the research contributed to it by our colleague and friend Kirill V. Kovtunov whose scientific career ended unexpectedly and tragically at the age of 37. His role in this research was certainly crucial, further enhanced by a vast network of his contacts and collaborations at the national and international level.