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Paper, the carrier of our written heritage, decays within a relatively short period of time mainly due to its acid content and the influence of air pollution. More than 50% of the records of our libraries and archives are already at risk. Mass deacidification allows this problem to be counteracted by significantly slowing down the deterioration of paper and thereby prolonging its life span. An overview of all relevant mass deacidification methods is given. As it was found that the 'papersave' method was the most suitable to meet Swiss requirements, a plant using an optimised version of this method was built and put into service in March 2000. Thanks to this optimisation, not only books and loose sheets but also documents in archival boxes could be mass-deacidified for the first time. Due to the necessity to analyse not only test papers but also original documents, new non-destructive testing methods had to be developed. Findings of basic investigations regarding treatment effects as well as results of routine quality control turned out to be very satisfactory.

Paper, the carrier of our written heritage, decays within a relatively short period of time mainly due to its acid content and the influence of air pollution. More than 50% of the records of our libraries and archives are already at risk. Mass deacidification allows this problem to be counteracted by significantly slowing down the deterioration of paper and thereby prolonging its life span. An overview of all relevant mass deacidification methods is given. As it was found that the 'papersave' method was the most suitable to meet Swiss requirements, a plant using an optimised version of this method was built and put into service in March 2000. Thanks to this optimisation, not only books and loose sheets but also documents in archival boxes could be mass-deacidified for the first time. Due to the necessity to analyse not only test papers but also original documents, new non-destructive testing methods had to be developed. Findings of basic investigations regarding treatment effects as well as results of routine quality control turned out to be very satisfactory.

A new approach based on non-pigmented, stable colored nanoparticles able to migrate upon application of an electrical field (10–60 V) has been developed for the improvement of the color brightness of e-displays. The scientific challenges comprised the development of efficient syntheses of tri- and bifunctional dendrimers including branching points for further extension and individual decoration with dye (yellow, magenta, cyan). The covalent attachment of these scaffolds to silica nanoparticles was performed via hydrosilylation and final in situ charging generated attractive silica shells for the substractive CMY color space model.

The exponential improvements made in DNA sequencing technologies, together with the rapidly declining associated costs, has increasingly led to the expansion of the field of personalised genomic medicine. Changes in the sequence or copy number of specific deoxyribonucleic acid (DNA) or ribonucleic acid (RNA) molecules represent key signatures for the diagnosis, prognosis, classification and monitoring of a broad range of pathologies, most notably cancer. Technologies that can detect these changes require analytical tools that can detect DNA or RNA with high sensitivity and high specificity. Sensing based on bioorthogonal oligonucleotide-templated reactions (OTRs) has been recognised as an elegant strategy that satisfies these criteria and was successfully used for the quantitative detection of nucleic acids both in vitro and in vivo. Herein, we will focus on recent efforts to implement bioorthogonal OTRs into clinically useful biosensors using probes immobilised on or embedded in customised materials and platforms.

We summarize here recent advancements on thin layer samples controlled by dynamic electrochemistry techniques for determining different ions that include potassium, calcium, protamine, nitrate, nitrite and halides in diverse environmental and clinical samples. Generally, a thin layer liquid (less than 100 μm in thickness) is confined between a working electrode and an ion-selective membrane. Once an external electrical perturbation (i.e. constant potential) is applied to the system, an exhaustive ion transfer process is imposed in the entire thin layer solution. As a result, the observed charge (integration of the current decay) is proportional to the depleted ion concentration. Other electrochemical protocols such as linear sweep voltammetry were also explored aiming at the discrimination of several ions presented in the thin layer. One of the most attractive examples involves the detection of a mixture of three halides (iodide, bromide and chloride), which can be well resolved at moderated scan rates (10 mV.s–1). Paper-based coulometric sensing on thin layers defined by cellulose papers are being developed in view of translating these new concepts into a reliable and low cost sensing platform.

This short paper presents the relationship between the pulp and paper industry and chemistry. The history of this industry is presented including current paper production and consumption statistics. The production of paper pulp is realized by chemically or mechanically separating cellulose fibres from wood and removing the unwanted lignin. This article concludes with an ecological aspect.

The Sabatier reaction is a key element of power-to-gas development. For this reason, even though the process is known since more than one century, the Sabatier reaction is currently the object of important research efforts towards the development of new catalysts for performance improvement. However, the industrial exploitation of the Sabatier reaction depends on the development of reactors that match the best catalyst with an appropriate heat management. For this reason, this paper develops a methodology for the contemporary optimization of the reactor concept and the catalysts. It is observed that the reactor can be divided into three sections with contrasting requirements. In the first section, the main requirement concerns the reach of the reaction activation conditions. Hence, an adequate match between catalyst and reactor is needed, for example with an appropriate pre-heater. Once the reaction is activated, a reaction hotspot is formed, so that the cooling becomes determining and the main requirement for the catalyst is the resistance to poisoning and sintering. In the last section of the reactor, the low temperature activity of the catalyst is determining, so that a high-performing catalyst is needed. This paper indicates a strategy for the rational design of this catalyst, based on mechanistic evidences.

The present paper introduces soil as a complex system, so a multidisciplinary approach is needed to study not only the composition, abundance, and transport of microplastics (MPs) in terrestrial ecosystems but also soil properties and processes involved in their degradation and/or interaction with soil polyphasic matrix. Despite many researchers focusing their studies on the impact of MPs on the terrestrial ecosystem over the past years, little has been done about the use of biochemical indicators to study their effect on soil functionality.

Some chemistry textbooks use an inappropriate colour model when discussing the colour of a substance that absorbs light at a specific wavelength. More specifically, these textbooks state that substances that absorb only in the violet end of the visible spectrum are green-yellow and substances that absorb only in the red end are blue-green. This paper presents a more accurate approach.

By using silver (Ag) in nanostructured (nanowire, nanosphere, etc.) or thin-layer form as a catalyst for electrochemical CO2 reduction, very high CO-forming selectivity of almost 100% can be achieved. Supported by gas diffusion layers (GDLs), the reactant CO2 in the gas phase can approach and potentially access active Ag sites, which allows current densities in the range of a few hundred mA cm–2 to be reached. Yet, the stability of gas diffusion electrode (GDE) based electrochemical CO2-to-CO converters is far from perfect, and the activity of GDE cathodes, especially when operated at high current densities, often significantly decays during electrolyses after no more than a few hours. The primary reason of stability losses in GDE-based CO2-to-CO electrolysers is flooding: that is, the excess wetting of the GDE that prevents CO2 from reaching Ag catalytic sites. In the past years, the authors of this paper at Empa and at the University of Bern, cooperating with other partners of the National Competence Center for Research (NCCR) on Catalysis, took different approaches to overcome flooding. While opinions differ with regard to where the first line of defense in protecting GDEs from flooding should lie, a comparison of the recent results of the two groups gives unique insight into the nature of processes occurring in GDE cathodes used for CO2 electrolysis.

CST (Crude Sulfate Turpentine) is an upcycled, biomass raw material derived from pinewood, obtained as a by-product of the Kraft process from the pulp and paper industry. The current article provides an overview of major renewable perfumery ingredients obtained from CST-derived alpha- and beta-pinene to-date and part of the Firmenich manufacturing portfolio, post DRT acquisition.

The discovery of novel antibacterials devoid of cross resistance is of utmost importance. At the same time, biological pathways and processes suitable to be targeted are limited. At Actelion Pharmaceuticals we decided to work on novel bacterial topoisomerase inhibitors (NBTI) to discover new antibiotics with broad spectrum activity and limited resistance development for use against severe hospital infections. This paper summarizes the learnings and results of our efforts in the field, which led to the discovery of multiple chemical classes with potent Gram-negative activity and ultimately to the selection of several compounds that underwent preclinical profiling.

Angle-resolved photoelectron spectroscopy (ARPES) is a powerful tool in solid state sciences. Beside the direct measurement of the energy-momentum dispersion relation, the angular distribution of the photoelectron current reveals the structural environment of the emitting atoms via photoelectron diffraction effects. Moreover, in the case of molecular layers, the angular distribution of emission from molecular orbitals can be directly related to their charge density distribution via so-called orbital tomography. In the present paper we summarize our efforts undertaken over the past 12 years to add the dimension of time to these two methods via pump-probe experiments with femtosecond resolution. We give a comprehensive introduction to standard ARPES and time-resolved two photon photoemission and then focus on our efforts towards time-resolved versions of photoelectron diffraction and orbital tomography. Both, optimization of experimental parameters and data acquisition procedures, as well as new numerical tools are needed in order to realize such challenging full stop missing after experiments.

Ipatasertib is a potent small molecule Akt kinase inhibitor currently being tested in Phase III clinical trials for the treatment of metastatic castration-resistant prostate cancer and triple negative metastatic breast cancer. In this paper an overview of the development achievements towards the commercial manufacturing process is given. The convergent synthesis consists of ten steps with eight isolated intermediates and utilizes a wide range of chemical techniques and technologies to build-up this complex drug. All three stereocenters are introduced using enzyme or metal catalysis.

We review our recent paper which resolves the long-standing dilemma of the location and nature of the six-fold coordinated aluminum in calcium aluminate silicate hydrate (C-A-S-H) samples. First principles calculations predict that at high Ca:Si and H2O ratios, aluminum is incorporated into the bridging sites of the linear silicate chains and that the stable coordination number is six. We confirm this hypothesis experimentally by one- and two-dimensional dynamic nuclear polarization enhanced 27 Al and 29 Si solid-state NMR experiments in which we correlate the distinctive six-fold coordinated aluminum NMR signal at 5 ppm to 29 Si NMR signals from silicates in C-A-S-H.

Metallic nanoparticles of different shape can be used as efficient electrocatalysts for many technologically and environmentally relevant processes, like the electroreduction of CO2. Intense research is thus targeted at finding the morphology of nanosized features that best suits catalytic needs. In order to control the shape and size distribution of the designed nanoobjects, and to prevent their aggregation, synthesis routes often rely on the use of organic capping agents (surfactants). It is known, however, that these agents tend to remain adsorbed on the surface of the synthesized nanoparticles and may significantly impair their catalytic performance, both in terms of overall yield and of product selectivity. It thus became a standard procedure to apply certain methods (e.g. involving UV-ozone or plasma treatments) for the removal of capping agents from the surface of nanoparticles, before they are used as catalysts. Proper design of the operating procedure of the electrocatalysis process may, however, render such cleaning steps unnecessary. In this paper we use poly-vinylpyrrolidone (PVP) capped Ag nanocubes to demonstrate a mere electrochemical, operando activation method. The proposed method is based on an observed hysteresis of the catalytic yield of CO (the desired product of CO2 electroreduction) as a function of the applied potential. When as-synthesized nanocubes were directly used for CO2 electroreduction, the CO yield was rather low at moderate overpotentials. However, following a potential excursion to more negative potentials, most of the (blocking) PVP was irreversibly removed from the catalyst surface, allowing a significantly higher catalytic yield even under less harsh operating conditions. The described hysteresis of the product distribution is shown to be of transient nature, and following operando activation by a single 'break-in' cycle, a truly efficient catalyst was obtained that retained its stability during long hours of operation.

The Fe-SMA developed at the Swiss Federal Laboratories for Materials Science and Technology (Empa) has an alloy composition of Fe–17Mn–5Si–10Cr–4Ni–1(V,C) and exhibits an excellent shape memory effect on heating at 160 °C or above. The shape memory effect feature equips Fe-SMA with a unique self-prestressing ability that can be exploited for many civil engineering applications. In addition to the self-prestressing ability, Fe-SMA has a high elastic modulus (165 GPa), low cost, and high machinability compared to the nickel and copper-based SMAs, which makes it more suitable for structural applications. The current work aims to provide an overview of the recent advancements in the research and development of Fe-SMA at Empa. To this end, the advancements related to the material development, applications of Fe-SMAs in prestressing reinforced concrete (RC) and metallic structures, and the introduction of Fe-SMA reinforcements to the market alongwith some recent field applications are presented. The paper concludes with an overview of the opportunities and challenges associated with using Fe-SMA reinforcements in civil infrastructure.

Asking students questions is a central, although understudied and underappreciated, ingredient of teaching. Formative questioning provides many opportunities for teachers and students, e.g. to practice skills and receive feedback. Among other approaches, classroom response systems (CRSs), which run on the mobile electronic devices of students, facilitate such active engagement of students in the lecture hall. This paper presents an overview on questions for teaching with a focus on questions for CRSs and provides considerations and brief guidelines for the development of multiple-choice questions. Examples from a mid-sized analytical chemistry lecture illustrate additional challenges and different probes for potential misconceptions. Moreover, limitations of valid interpretation of students' responses are emphasized. This leads to a discussion of the value of incorporating prompts for justifications into questions.

Radiopharmacy at ETH has worked on the development of novel PET tracers for neuro-, cardiac- and tumor imaging for many years. In this paper, our efforts on targeting the glutamatergic system of the metabotropic glutamate receptor subtype 5 (mGluR5) and the ionotropic N-methyl-D-aspartate (NMDA) receptor are summarized. We briefly described the principles of positron emission tomography (PET) tracer development for the central nervous system (CNS) and the radiolabeling methods used in our laboratory. To assess the radioligands, results of in vitro autoradiography, biodistribution, and metabolite studies as well as PET imaging data are discussed. Furthermore, key PET parameters for kinetic modeling and quantification methods are provided. Two mGluR5 PET tracers, [11C]ABP688 and [18F]PSS232, were translated in our GMP labs and evaluated in human subjects. The newly developed GluN2B PET tracer [11C]Me-NB1 is currently being investigated in a first-in-human PET study and several F-18 labeled tracers are being evaluated in non-human primates in which the first-in-class will be translated for human studies.

In a bilingual paper entitled 'Bibliometrics as weapons of mass citation – La bibliométrie comme arme de citation massive', recently translated into English, we have argued that the current fashion of ranking people, papers and journals is anything but harmless. The point was forcefully supported by Richard Ernst in a post-face entitled 'The Follies of Citation Indices and Academic Ranking Lists.' We received a surprising number of passionate responses, such as 'It's written out of my heart' (TH); 'Je soutiens cette entreprise courageuse de tout coeur' (VT); 'Impact Faktoren sind ein Marktinstrument gewisser Verlage (FS); 'Il y a un combat à mener' (SB). Some thoughtful responses have been incorporated into this Essay, albeit in attenuated form. We suggest that the 'fertility' of individual scientists be appreciated in terms of kinship rather than through personalized indices.

This paper summarizes a personal perspective on key learnings from projects the author was involved in over the last 20 years. For example, the discovery of macitentan, the most successful molecule to date from this personal collection, marketed by J&J for the treatment of pulmonary arterial hypertension (PAH). [1] Then the discovery of ACT-462206, a dual orexin receptor antagonist for the treatment of insomnia disorder with a serendipitously short story from the screening hit to the drug [2] followed by the identification of daridorexant, another dual orexin receptor antagonist. Daridorexant successfully passed first pivotal phase 3 clinical trial in April 2020 for the treatment of insomnia disorder [3] ("Good things come to those who wait"). Finally, ACT-451840, an antimalarial drug with a novel mechanism of action, identified in the perfect collaboration between academia and industry. The compound is in phase 2 clinical development. [4] In addition, the importance of the screening compound collection is briefly discussed, as a key asset for drug discovery. The measures Idorsia implemented to obtain valuable hits from high-throughput screening (HTS) campaigns are elaborated. [5] Drug discovery is a multi-disciplinary business with unlimited exciting challenges asking for excessive optimism when tackling them in a playful manner.

The TrainMiC® (Training in Metrology in Chemistry) programme is a European programme for Life-Long Learning in metrology in chemistry, which is a truly unique system operational across many parts of Europe (19 countries) via national teams. It uses shareware pedagogic tools and the learning content has been harmonised at the European level by a joint effort of many experts across Europe working via an Editorial Board. This paper gives an overview of the activities within the TrainMiC® programme where there is an interaction with national accreditation bodies and the European Cooperation for Accreditation. It is the responsibility of the accreditation bodies to ensure that outcome of the assessments is reliable and transparent and is meeting the relevant requirements. The paper explains the potential of TrainMiC® in providing a tool for accreditation bodies to ensure a harmonised level of knowledge in a specific sector of those who are involved in technical assessments for accreditation in the field of chemical measurements. Some use the word inter-calibration to describe this process.

Three years ago a bibliometric index for the qualification of a person's scientific output was proposed by Hirsch, the so-called h index. This is an integer number which combines the number of papers of an author and the number of citations they gathered. Thus the h index is an indicator for both the productivity and the impact of a scientist. This paper presents the properties of the h index and the great attention it attracted within a short time. Numerous other indices, claimed to be better than the original, were proposed in the meantime. These developments are discussed critically.

With the emergence of nanotechnology in drug delivery, colloidal systems and particularly polymeric micelles have attracted great attention. Polymeric micelles formed by the self-assembly of amphiphilic copolymers adopt a core-shell structure, which can be loaded with drugs and used as drug delivery systems for various medical applications. The most interesting aspects involve extended blood circulation times and stability upon dilution, which enable polymeric micelles to accumulate in tumor or inflammation sites due to the enhanced permeation and retention effect (EPR). In the first part of this paper polymeric micelles with different morphologies and different circulating-, active- and passive targeting, and stimuli responsive properties will be reviewed. Furthermore amphiphilic block copolymers of different compositions for pharmaceutical micelle formulations will be discussed. The hydrophilic block is often composed of the biocompatible polyethylene glycol (PEG), whereas diverse polymers are used for the hydrophobic block. The biodegradable and biocompatible polylactide (PLA) is one of the most tested core-forming blocks for micelles, in part because of approval by the FDA for numerous drug products for use in humans. However, PLA has limitations with respect to the incorporation of poorly water-soluble drugs. Considering this we will present in the second part of this paper briefly our strategy and contribution to overcome these limitations and recent results for the envisioned application of these micelles in the field of cancer treatment. In order to increase the hydrophobicity of PLA methyl groups are substituted by more hydrophobic hexyl groups. The hexyl-substituted polylactides in combination with PEG form the amphiphilic block copolymers PEG-hexPLA, which self-assemble in aqueous solution into stable spherical, homogenous micelles with a diameter of 20–45 nm. The increased hydrophobicity of the hexPLA micelle core leads to higher incorporation rates of hydrophobic drugs, like the poorly water soluble photosensitizer, meso-tetra(p-hydroxyphenyl)porphine (THPP). THPP water solubility is increased 200-fold using these micelles. Their application in photodynamic therapy (PDT), coupled with the increased accumulation of the photosensitizer in a tumor, followed by irradiation at a special wavelength, should lead to tumor death. The encouraging drug incorporation results reveal the potential of hexyl-substituted polylactide micelles as drug carriers for PDT applications.

The paper discusses the position and role of environmental chemistry among the other environmental disciplines. It discusses the various aspects of environmental chemistry and emphasizes the need for developing fundamental studies in biophysical environmental chemistry in order to better understand the functioning of environmental systems. These systems include a large number of various structures in the nanometer to meter range which play key roles on compound fluxes and consequently on the homeostasis of ecosystems and on their disturbance by anthropogenic activities. Both structures and fluxes are presently ill-known and new concepts and methods must be developed in this field. For chemistry, this is a challenging area where supramolecular structures and processes play dominant roles. It is also a challenging field for the development of environmental sciences since detailed and sound physico-chemical processes are needed in macroscopic modeling of compound circulation in ecosystems. In addition, teaching this discipline to chemistry students would allow them to confront complex, structured real systems. This paper also discusses the relationship between biophysical environmental chemistry and the other environmental disciplines within integrated multidisciplinary studies. The structure used at the Faculty of Sciences of the University of Geneva to favour a flexible but efficient integration is briefly described.

The paper discusses the position and role of environmental chemistry among the other environmental disciplines. It discusses the various aspects of environmental chemistry and emphasizes the need for developing fundamental studies in biophysical environmental chemistry in order to better understand the functioning of environmental systems. These systems include a large number of various structures in the nanometer to meter range which play key roles on compound fluxes and consequently on the homeostasis of ecosystems and on their disturbance by anthropogenic activities. Both structures and fluxes are presently ill-known and new concepts and methods must be developed in this field. For chemistry, this is a challenging area where supramolecular structures and processes play dominant roles. It is also a challenging field for the development of environmental sciences since detailed and sound physico-chemical processes are needed in macroscopic modeling of compound circulation in ecosystems. In addition, teaching this discipline to chemistry students would allow them to confront complex, structured real systems. This paper also discusses the relationship between biophysical environmental chemistry and the other environmental disciplines within integrated multidisciplinary studies. The structure used at the Faculty of Sciences of the University of Geneva to favour a flexible but efficient integration is briefly described.

Machine Learning and Data Science have enjoyed a renaissance due to the availability of increased computational power and larger data sets. Many questions can be now asked and answered, that previously were beyond our scope. This does not translate instantly into new tools that can be used by those not skilled in the field, as many of the issues and traps still exist. In this paper, we look at some of the new tools that we have created, and some of the difficulties that still need to be taken care of during the transition from a project run by an expert, to a tool for the bench chemist.

This paper discusses the application of the circular economy concept and industrial ecology approach in the context of industrial chemical sites. A real-life case study about the use of bromine as reactant for chemical synthesis and its recycling by Syngenta in Monthey is described in detail. With a recovery yield of 97% it represents a well-established example of closed loop recycling, one aspect of the circular economy. The process leads to significant safety and environmental risk reduction and economic savings in the order of several million CHF per year.

Kossel and Lewis' description of the chemical bonding in ionic and covalent compounds in 1916 made an important contribution, which connected the Periodic Table to modern valence theory. In a 1919 paper Langmuir made the perceptive observation that neutral molecules, which had the same number of electrons, e.g. N2 and CO and N2O and CO2, had remarkably similar physico-chemical properties. Inorganic chemists have used this isoelectronic principle to interconnect a wide range of compounds and thereby explore the implications of the Periodic Table.

The first comparison of heterochiral crystals with their homochiral counterparts was given by Otto Wallach in an account on carvone bromide crystals in 1895 in Liebigs Annalen der Chemie. Although the well-known mineralogist Theodor Liebisch, professor in Göttingen from 1887 to 1908, performed the analyses and wrote the last four pages of that Annalen paper, his colleague from chemistry, Wallach served as sole author. We discuss whether Wallach or Liebisch had the idea of a comparative study of crystal densities of racemates and their homochiral analogues and who of the two should be credited.

The study of molecular chirality is essential to understanding the fundamentals of enantiospecific chemical interactions that are ubiquitous in the biochemistry of life on Earth. At a molecular level, there is insufficient understanding of chiral recognition and enantiomer–enantiomer interaction (aggregation) of chiral molecules adsorbed on surfaces. Here, using enantiospecific isotopic labelling and surface sensitive techniques, we show that when the two enantiomers of chiral aspartic acid (Asp) are adsorbed on the naturally chiral Cu(643)R&S surfaces, they decompose enantiospecifically depending on the chirality of the surface. The non-linear kinetics of the surface decomposition mechanism amplifies the difference between the decomposition rate constants of the two adsorbed enantiomers resulting in highly enantiospecific decomposition rates. Further, we also demonstrate that Asp enantiomers aggregate homochirally on several chiral and achiral surfaces, amplifying the enantiomeric excess on the surface with respect to that in the gas phase, |ees |>|eeg. Our results show that it is possible to discern the enantiospecific behavior of a complex adsorbate such as Asp and shed light on molecular level enantiospecific interactions on surfaces. The enantiospecific isotope labelling methods discussed in this paper allow probing of both the qualitative features of the Asp decomposition mechanism on Cu(643)R&S and quantitative aspects of the adsorption equilibria of enantiomer mixtures.

Photocatalytic hydrogen production is an appealing way to store solar energy as chemical fuel. The most studied molecular catalysts for H2 production are based on earth-abundant metals such as Ni, Co and Fe. Efforts have been recently focused on the design of Co complexes with distorted octahedral geometries induced by tetra- or pentapyridyl ligands. We synthesized a new Co(II) complex based on a hexapyridyl ligand that leads to the formation of an unusual heptacoordinate structure. In this paper, we review the characterization of the new catalyst and the optimization of the conditions for hydrogen evolution. The high activity reached after two hours of irradiation under visible light (475 nm) suggests that heptacoordinate cobalt complexes, not used so far in the field of light-driven hydrogen evolution, represent a promising alternative platform for the development of highly active and stable photocatalysts.

e-Learning has become increasingly important in chemical education and online exams can be an attractive alternative to traditional exams written on paper, particularly in classes with a large number of students. Ten years ago, we began to set up an e-course complementing our lecture courses Organic Chemistry I and II within the open-source e-learning environment Moodle. In this article, we retrace a number of decisions we took over time, thereby illustrating the challenges one faces when creating online exercises and exams in (organic) chemistry. Special emphasis is put on the development of MOSFECCS (MOlecular Structural Formula Editor and Calculator of Canonical SMILES), our new editor for drawing structural formulae and converting them to alphanumeric SMILES codes that can be submitted as answers to e-problems. Convinced that the possibility for structure input is essential to set up sensible chemistry quizzes and exams, and realising that existing tools present major flaws in an educational context, we decided to embark on the implementation of MOSFECCS which takes into account a number of didactic aspects.

This review summarizes possibilities of including scientific methods for investigation of art objects into the secondary school chemistry curriculum. We discuss methods such as X-ray radiography, infrared reflectography, neutron activation autoradiography, X-ray fluorescence, and Raman spectroscopy and provide recent examples of their use. The results obtained, especially when combined with modern digital image processing algorithms, are indeed impressive. The second part of the paper is devoted to suggestions for actual use in teaching. The activities in the classroom can be centered around scientific investigation of a single painting, properties and use of a single pigment, or utilizing parallels in the history of Chemistry and history of Art. Finally, scientific methods for detecting art fraud including actual historical examples are especially motivating for the students and various teaching activities can be designed around this aspect.

The natural product Rocaglamide (1), isolated from the tree Aglaia elliptifolia, is a compelling but also challenging lead structure for crop protection. In laboratory assays, the natural product shows highly interesting insecticidal activity against chewing pests and beetles, but also phytotoxicity on some crop plants. Multi-step syntheses with control of stereochemistry were required to probe the structure–activity relationship (SAR), and seek simplified analogues. After a significant research effort, just two areas of the molecule were identified which allow modification whilst maintaining activity, as will be highlighted in this paper.

Chemical space describes all possible molecules as well as multi-dimensional conceptual spaces representing the structural diversity of these molecules. Part of this chemical space is available in public databases ranging from thousands to billions of compounds. Exploiting these databases for drug discovery represents a typical big data problem limited by computational power, data storage and data access capacity. Here we review recent developments of our laboratory, including progress in the chemical universe databases (GDB) and the fragment subset FDB-17, tools for ligand-based virtual screening by nearest neighbor searches, such as our multi-fingerprint browser for the ZINC database to select purchasable screening compounds, and their application to discover potent and selective inhibitors for calcium channel TRPV6 and Aurora A kinase, the polypharmacology browser (PPB) for predicting off-target effects, and finally interactive 3D-chemical space visualization using our online tools WebDrugCS and WebMolCS. All resources described in this paper are available for public use at www.gdb.unibe.ch.

We present our research findings related to new formulations of the organic additives (grinding aids) needed for the efficient grinding of inorganic solids. Even though the size reduction phenomena of the inorganic solid particles in a ball mill is purely a physical process, the addition of grinding aids in milling media introduces a complex physicochemical process. In addition to further gain in productivity, the organic additive helps to reduce the energy needed for grinding, which in the case of cement clinker has major environmental implications worldwide. This is primarily due to the tremendous amounts of cement produced and almost 30% of the associated electrical energy is consumed for grinding. In this paper, we examine the question of how to optimize these grinding aids linking molecular insight into their working mechanisms, and also how to design chemical additives of improved performance for industrial comminution.

Cellulose nanocrystals (CNCs) are rod-like nano-scale particles that are widely available in nature and have recently gained great interest in both research and industry, due to their high strength, high crystallinity, high surface area, low density, biodegradability and low toxicity. CNCs can be easily extracted from natural cellulose sources and are broadly useful, for example in polymer reinforcement, paper manufacturing, and rheology modification. The high density of functional groups on the surface of CNCs allows various chemical surface modifications, which permit tuning the properties of CNCs over a wide range. This review gives a brief overview of surface chemical modification of CNCs, focusing especially on those often utilized for our own research, which focuses on some of the most prominent areas of interests of CNCs, notably polymer reinforcement, healable polymers, stimuli-responsive nanohybrids, Pickering emulsion stabilizers, viral inhibitors, and cholesteric liquid crystal assemblies.

Polymer chemistry has recently welcomed a new addition to its field: the planar macromolecules known as two-dimensional polymers (2DPs). These topologically planar and crystalline monolayer covalent sheets are reminiscent of molecular fishermen's nets and apart from being conceptually very interesting for the field of macro-molecular chemistry, they also show some potential applications as novel 2D materials. This article reviews how the field has developed five years after the first 2DP was synthesised in 2012. After a brief historical introduction, the main synthetic approaches will be discussed providing concrete examples of 2DPs and highlighting the challenges associated with the synthesis and especially structural characterisation of these fascinating macro-molecules. Finally an overview on their potential applications such as membranes for gas separation, rewritable molecular paper and miniaturisation of optical devices will be presented.

Malaria is one of the leading infectious diseases occurring mainly in tropical and subtropical areas. Although available antimalarial tools have reduced the number of fatalities, there is still an urgent need for the development of new and more efficacious treatments to cure and eradicate malaria especially due to emerging resistance to all antimalarial drugs. Research was initiated to revisit antimalarial compounds which were deemed unsuitable as a result of poor understanding of physicochemical properties and the optimization thereof. The 4(1H)-quinolones are a class of compounds with demonstrated activity against malaria parasites. Recent optimization of the long-known core led to two highly promising compounds, i.e. P4Q-391 and ELQ-300, with great selective activity against all stages of the parasite's life cycle and good physicochemical properties. In this paper, we discuss the key steps on the way to these compounds, which fuel hope to find a suitable treatment for the prevention, cure and eradication of malaria.

Computational models in chemistry rely on a number of approximations. The effect of such approximations on observables derived from them is often unpredictable. Therefore, it is challenging to quantify the uncertainty of a computational result, which, however, is necessary to assess the suitability of a computational model. Common performance statistics such as the mean absolute error are prone to failure as they do not distinguish the explainable (systematic) part of the errors from their unexplainable (random) part. In this paper, we discuss problems and solutions for performance assessment of computational models based on several examples from the quantum chemistry literature. For this purpose, we elucidate the different sources of uncertainty, the elimination of systematic errors, and the combination of individual uncertainty components to the uncertainty of a prediction.

Historically, many of the classical organic fluorescent dyes were developed as laser dyes and characterized and optimized in organic solvents. Since then, fluorescence has, however, found a vast range of applications in the life sciences in which the fluorophores are usually surrounded by water and not by organic solvents. The omnipresence of water in biomolecular fluorescence spectroscopy and imaging leads to some unwanted but nonetheless unavoidable consequences on the photophysical properties of the dyes, which may impact the quality and complicate quantitative interpretation of the experiments. This paper discusses and illustrates with examples two such water-induced phenomena, namely chromophore aggregation in water and fluorescence quenching by water, as well as some ways to overcome them.

Imaged-based screening has been developing extremely quickly in the past 10 years. Academic institutes quickly realized that the discovery capacity of this technology was huge, allowing the automatic detection and quantification of complex cell phenotypes. Associated with chemical or genetic perturbations, high content screening is the method of choice for a deep system biology analysis. The evolution of high-content screening is mainly due to the recent progress in the development of fast and high quality automated imagers and of a plethora of new very bright fluorescent markers, so that almost any cellular element can be seen and imaged. In this paper we review and summarize the major steps in the development of an image-based screening project.

Widespread pyrethroid resistance has caused an urgent need to develop new insecticides for control of the malaria mosquito, Anopheles gambiae. Insecticide discovery efforts were directed towards the construction of bivalent inhibitors that occupy both the peripheral and catalytic sites of the mosquito acetylcholinesterase (AChE). It was hypothesized that this approach would yield a selective, high potency inhibitor that would also circumvent known catalytic site mutations (e.g. G119S) causing target site resistance. Accordingly, a series of bivalent phthalimide-pyrazole carbamates were prepared having an alkyl chain linker of varying length, along with other modifications. The most active compound was (1-(3-(1,3-dioxoisoindolin-2-yl)propyl)-1H-pyrazol-4-yl methylcarbamate, 8a), which has a chain length of three carbons, good mosquito anticholinesterase activity, and ca. 5-fold selectivity compared to human AChE. Moreover, this compound was toxic to mosquitoes by topical application (LD50 = 63 ng/female) with only 6-fold cross resistance in the Akron strain of Anopheles gambiae that showed 50- to 60-fold resistance to conventional carbamate insecticides. However, contact lethality in the WHO paper assay was disappointing. The implications of these results for design of new mosquitocides are discussed.