1,677 results match your criteria Chimia[Journal]


XXII. Symposium on Atomic, Cluster and Surface Physics (SASP).

Authors:
Karl-Heinz Ernst

Chimia (Aarau) 2020 Jun;74(6):509-511

Empa, Swiss Federal Laboratories for Materials Science and Technology, Ueberlandstrasse 129, CH-8600 Dübendorf;, Email:

From Sunday February 2, 2020 until the following Friday, 75 scientists from all over the world gathered in Hotel Laudinella in St. Moritz to discuss their latest findings about surface, cluster and gas phase physics and chemistry. A program consisting of 25 invited speakers, 16 hot topic oral contributions and 27 poster presentations has been put together by the organizers from Empa. Read More

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http://dx.doi.org/10.2533/chimia.2020.509DOI Listing

Bringing Chemistry to Medicine - The Contribution of Paracelsus to Modern Toxicology.

Authors:
Martin F Wilks

Chimia (Aarau) 2020 Jun;74(6):507-508

Swiss Centre for Applied Human Toxicology & Dept. of Pharmaceutical Sciences, University of Basel, Missionsstrasse 64, Ch-4055 Basel;, Email:

At the heart of Paracelsus' medical theory is the belief that all matter can be reduced to three basic elements: sulphur, mercury and salt. Their unique properties can be harnessed in the preparation of specific medicines. In this way, poisons can become medicines since it is the dose that determines toxicity. Read More

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http://dx.doi.org/10.2533/chimia.2020.507DOI Listing

Ultrasensitive Quantification of Pyrethroid and Organophosphate Insecticides in Surface Water.

Chimia (Aarau) 2020 Jun;74(6):506

Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH-8600 Dübendorf;, Email:

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http://dx.doi.org/10.2533/chimia.2020.506DOI Listing

A Diiron Hydrogenase Mimic Featuring a 1,2,3-Triazolylidene.

Chimia (Aarau) 2020 Jun;74(6):499-503

Laboratoire de Chimie, Electrochimie Moléculaires et Chimie Analytique, UMR 6521 CNRS - Université de Bretagne Occidentale, CS 93837 - 6 Avenue Le Gorgeu, 29238 BREST Cedex 3 - France;, Email:

A novel complex featuring a mesoionic carbene [Fe₂(CO)(trz)(μ-pdt)] () (trz = 1-phenyl-l,3-methyl,4-butyl-1,2,3-triazol-5-ylidene), was synthesized and spectroscopically and structurally characterized. The reductive behaviour of this compound in the presence and in the absence of acid (CH₃CO₂H) was examined by cyclic voltammetry (CV) that revealed the lack of efficient activity towards proton reduction. Read More

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http://dx.doi.org/10.2533/chimia.2020.499DOI Listing

Mechanistic Studies of the Oxidative Addition of Aryl Halides to Ni(0) Centers Bearing Phosphine Ligands.

Chimia (Aarau) 2020 Jun;74(6):495-498

Organic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 GC, Utrecht, The Netherlands;, Email:

The oxidative addition of aryl halides is a common entry point in catalytic cycles for cross-coupling and related reactions. In the case of phosphine-supported nickel(0) fragments, the formation of reactive Ni(ii)-aryl products often competes with the production of Ni(i) species. Here, recent advances in the mechanistic understanding of these reactions are highlighted. Read More

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http://dx.doi.org/10.2533/chimia.2020.495DOI Listing

On the Ability of Nickel Complexes Derived from Tripodal Aminopyridine Ligands to Catalyze Arene Hydroxylations.

Chimia (Aarau) 2020 Jun;74(6):489-494

Organic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands;, Email:

The development of catalysts for the selective hydroxylation of aromatic C-H bonds is an essential challenge in current chemical research. The accomplishment of this goal requires the discovery of powerful metal-based oxidizing species capable of hydroxylating inert aromatic bonds in a selective manner, avoiding the generation of non-selective oxygen-centered radicals. Herein we show an investigation on the ability of nickel(ii) complexes supported by tripodal tetradentate aminopyridine ligands to catalyze the direct hydroxylation of benzene to phenol with H₂O₂ as oxidant. Read More

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http://dx.doi.org/10.2533/chimia.2020.489DOI Listing

-Functionalised NHC Ligands for Efficient Nickel-catalysed C-O Hydrosilylation.

Chimia (Aarau) 2020 Jun;74(6):483-488

Departement für Chemie und Biochemie, Universität Bern, Freiestrasse 3, CH-3012 Bern, Switzerland;, Email:

A series of C,O-bidentate chelating mesoionic carbene nickel(ii) complexes [Ni(NHC^PhO)₂] (NHC = imidazolylidene or triazolylidene) were applied for hydrosilylation of carbonyl groups. The catalytic system is selective towards aldehyde reduction and tolerant to electron-donating and -withdrawing group substituents. Stoichiometric experiments in the presence of different silanes lends support to a metal-ligand cooperative activation of the Si-H bond. Read More

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http://dx.doi.org/10.2533/chimia.2020.483DOI Listing

A Short Perspective on Electrochemical CO₂ Reduction to CO.

Chimia (Aarau) 2020 Jun;74(6):478-482

Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany; State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China; ; Email:

This short review summarizes examples of many homogeneous non-noble catalysts for CO₂-to-CO reduction and compares their feasible mechanisms. The focus is to show that elucidating the electronic structure of the catalytic system likely provides better understanding of the reaction mechanism and product selectivity. Read More

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http://dx.doi.org/10.2533/chimia.2020.478DOI Listing

Catalytic Oxidation of Primary C-H Bonds in Alkanes with Bioinspired Catalysts.

Chimia (Aarau) 2020 Jun;74(6):470-477

Institut de Química Computacional i Catálisi (IQCC), Departament de Química, Universitat de Girona C/M. Aurélia Capmany 69, Girona (17003), Spain;, Email:

Catalytic oxidation of primary C-H bonds of alkanes with a series of iron and manganese catalysts is investigated. Products resulting from oxidation of methylenic sites are observed when hexane () is used as model substrate, while corresponding primary C-H bonds remain unreactive. However, by using 2,2,3,3-tetramethylbutane () as model substrate, which only contains primary alkyl C-H bonds, oxidation takes place catalytically using a combination of hydrogen peroxide, a manganese catalyst and acetic acid as co-catalyst, albeit with modest yields (up to 4. Read More

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http://dx.doi.org/10.2533/chimia.2020.470DOI Listing

Computational Chemistry and Non-noble Metal-catalyzed Cross-coupling Reaction Mechanisms.

Chimia (Aarau) 2020 Jun;74(6):467-469

Department of Chemistry, KU Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium.

This short overview discusses the contribution that computational methods can make to the study of reaction mechanisms in non-noble-metal-catalyzed cross-coupling reactions. The differences between such reactions and those catalyzed by more traditional noble metals are emphasized, together with the challenge this poses to computation. Read More

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http://dx.doi.org/10.2533/chimia.2020.467DOI Listing

Bioinspired Non-Heme Iron Complexes: The Evolution of Facial Ligand Design.

Chimia (Aarau) 2020 Jun;74(6):450-466

Utrecht University, Organic Chemistry & Catalysis, Debye Institute for Nanomaterials Science, Faculty of Science, 3584 CG Utrecht, The Netherlands;, Email:

Iron-containing metalloenzymes that contain the 2-His-1-Carboxylate facial triad at their active site are well known for their ability to activate molecular oxygen and catalyse a broad range of oxidative transformations. Many of these reactions are synthetically challenging, and developing small molecular iron-based catalysts that can achieve similar reactivity and selectivity remains a long-standing goal in homogeneous catalysis. This review focuses on the development of bioinspired facial ligands that model the 2-His-1-Carboxylate facial triad to a greater degree of structural accuracy than many of the polydentate -donor ligands commonly used in this field. Read More

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http://dx.doi.org/10.2533/chimia.2020.450DOI Listing

Mechanistic Investigations of Nickamine- catalyzed Hydrosilylation of Alkenes: Nickel Nanoparticles Are the Active Species.

Chimia (Aarau) 2020 Jun;74(6):444-449

Ecole Polytechnique Fédérale de Lausanne, Institute of Chemical Sciences and Engineering, EPFL-ISIC-LSCI, CH-1015 Lausanne;, Email:

Hydrosilylation is an important chemical process for the synthesis of organosilanes and for the production of silicone polymers. The wide variety of catalysts developed for this reaction generally follow a Chalk-Harrod, or a sigma-bond metathesis mechanism. Recently, our group developed a nickel pincer complex, Nickamine, for highly selective hydrosilylation of alkenes. Read More

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http://dx.doi.org/10.2533/chimia.2020.444DOI Listing

Editorial.

Chimia (Aarau) 2020 Jun;74(6):441

University of Bern.

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TEDD Competence Centre Report 2019.

Chimia (Aarau) 2020 May;74(5):426-428

Head of TEDD, Competence Centre TEDD, Institute of Chemistry and Biotechnology (ICBT), ZHAW Zurich University of Applied Sciences, Wädenswil, Switzerland;, Email:

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http://dx.doi.org/10.2533/chimia.2020.426DOI Listing

Membrane Filtration: Expanding the Areas of Application by Chemical Modification - Examples from the FHNW.

Chimia (Aarau) 2020 May;74(5):423-425

Institute of Chemistry and Biological Chemistry; University of Applied Sciences and Arts Northwestern Switzerland, Hofackerstrasse 30, CH-4132 Muttenz;, Email:

Membrane filtration applications are omnipresent in production processes of the food and beverage industry, in pharmaceutical production and the petrochemical industry but also in water purification for drinking water production and wastewater treatment. The main separation principle in membrane filtration is based on size exclusion which is dependent on the pore size of the membrane. Current developments based on chemical modification of these membranes have the goal to confer an additional chemical selectivity to membranes in order to broaden their areas of application. Read More

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http://dx.doi.org/10.2533/chimia.2020.423DOI Listing

Plant Toxins: Poison or Therapeutic?

Chimia (Aarau) 2020 May;74(5):421-422

Department of Chemistry, University of Basel, BPR 1096, Mattenstrasse 24a, CH-4058 Basel;, Email:

Many plants that are classed as poisonous also have therapeutic uses, and this is illustrated using members of the and genera which are sources of cardiac glycosides. Read More

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http://dx.doi.org/10.2533/chimia.2020.421DOI Listing

A Bio- Approach to Catalysis in the Pharmaceutical Industry.

Chimia (Aarau) 2020 May;74(5):407-417

Chemical and Analytical Development, Novartis Pharma AG, CH-4056 Basel, Switzerland.

Enzymes have the potential to catalyse complex chemical reactions with unprecedented selectivity, under mild conditions in aqueous media. Accordingly, there is serious interest from the pharmaceutical industry to utilize enzymes as biocatalysts to produce medicines in an environmentally sustainable and economic manner. Prominent advances in the field of biotechnology have transformed this potential into a reality. Read More

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http://dx.doi.org/10.2533/chimia.2020.407DOI Listing

Taming the Beast of Biology: Synthetic Biology and Biological Systems Engineering.

Authors:
Sven Panke

Chimia (Aarau) 2020 May;74(5):402-406

Department of Biosystems Science and Engineering, ETH Zurich, Mattenstrasse 26, Zurich, Switzerland;, Email:

Despite the availability of a variety of ' -omics ' technologies to support the system-wide analysis of industrially relevant microorganisms, the manipulation of strains towards an economically relevant goal remains a challenge. Remarkably, our ability to catalogue the participants in and model ever more comprehensive aspects of a microorganism's physiology is now complemented by technologies that permanently expand the scope of engineering interventions that can be imagined. In fact, genome-wide editing and re-synthesis of microbial and even eukaryotic chromosomes have become widely applied methods. Read More

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http://dx.doi.org/10.2533/chimia.2020.402DOI Listing

Development of Biopolyesters (PHA) as Part of the Swiss Priority Program in Biotechnology.

Authors:
Manfred Zinn

Chimia (Aarau) 2020 May;74(5):398-401

HES-SO Valais-Wallis (University of Applied Sciences and Arts Western Switzerland Valais), Institute of Life Technologies, Route du Rawyl 47, CH-1950 Sion 2, Switzerland;, Email:

The Swiss Priority Program in Biotechnology of the Swiss National Science Foundation that lasted between 1992 and 2001 had a boosting effect on many biotech disciplines and on the developments of polyhydroxyalkanoates (PHAs) in Switzerland in particular. The funding organization led by Prof. Oreste Ghisalba enabled a better understanding of the PHA biosynthesis and the development, as well as the implementation of novel bioprocesses ( two-phase fermentations, multiple nutrient limited growth conditions, multi-stage chemostats, and product formation in different host organisms). Read More

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http://dx.doi.org/10.2533/chimia.2020.398DOI Listing

Effects of Sodium Chloride on Tyramine Production in a Fermented Food Model and its Inhibition by Tyrosine-degrading JA-1199.

Chimia (Aarau) 2020 May;74(5):391-397

Laboratory of Food Biotechnology, Institute of Food, Nutrition and Health, ETH Zurich, Schmelzbergstrasse 7, CH-8092 Zurich, Switzerland;, Email:

Tyramine is a health-adverse biogenic amine, which can accumulate in fermented foods like cheese by decarboxylation of the free amino acid tyrosine by either starter cultures or resident microbes such as lactic acid bacteria including spp., respectively. Our study aimed to show the effect of sodium chloride concentrations on tyramine production as well as to characterise bacterial strains as anti-tyramine biocontrol agents in a 2 mL micro-cheese fermentation model. Read More

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http://dx.doi.org/10.2533/chimia.2020.391DOI Listing

Isolation and Identification of Actinomycetes Strains from Switzerland and their Biotechnological Potential.

Chimia (Aarau) 2020 May;74(5):382-390

Institute of Chemistry and Biotechnology, Microbiology and Molecular Biology, ZHAW, Campus Reidbach;, Email:

Actinomycetes strains isolated from different habitats in Switzerland were investigated for production of antibacterial and antitumoral compounds. Based on partial 16S rRNA gene sequences, the isolated strains were identified to genus level. as the largest genus of was isolated the most frequently. Read More

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http://dx.doi.org/10.2533/chimia.2020.382DOI Listing

The Role of Reaction Engineering in Bioprocess Development.

Authors:
Udo Kragl

Chimia (Aarau) 2020 May;74(5):378-381

Department of Chemistry, Industrial and Applied Chemistry, University of Rostock, Albert-Einstein-Str. 3A, 18059 Rostock, Germany; Department Life, Light and Matter, University of Rostock, 18051 Rostock, Germany;, Email:

This short review highlights the role of reaction engineering as a tool for bioprocess development. Selected examples are discussed that demonstrate the need to understand thermodynamic and kinetic properties of the reaction system in order to identify potential bottlenecks. For coupled enzyme systems and reaction cascades modelling as well as selection of suitable reactor configurations is discussed. Read More

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http://dx.doi.org/10.2533/chimia.2020.378DOI Listing

The Development of Biocatalysis as a Tool for Drug Discovery.

Chimia (Aarau) 2020 May;74(5):368-377

Chair for Bioprocess Engineering, TU Dortmund University, Emil-Figge-Str. 66, D-44227 Dortmund, Germany.

Enzymes are versatile biocatalysts capable of performing selective reactions. The advantages of enzymes in comparison to classical chemistry including chemical catalysts are the generally milder process conditions and avoidance of harmful reactants. Their high selectivity and specificity are especially beneficial for the enzymatic synthesis of new products with potential applications in drug research. Read More

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http://dx.doi.org/10.2533/chimia.2020.368DOI Listing

Polyhistidine Affinity Chromatography: From the Idea to a Method of Broad Applicability and the Pitfalls in-between.

Authors:
Heinz Döbeli

Chimia (Aarau) 2020 May;74(5):363-367

Lupsingerstrasse 22, CH-4417 Ziefen, Switzerland;, Email:

The present article recapitulates the development of the polyhistidine affinity tag purification principle. Emphasis is laid on events behind the scenes which were never published. The key concept of the method emerged in a team discussion and its further development was driven by the need of Roche in-house projects. Read More

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http://dx.doi.org/10.2533/chimia.2020.363DOI Listing

The Swiss Biotech Association (SBA) and Unitectra, the Joint Tech Transfer Organization of the Universities of Basel, Bern and Zurich - Two Organizations Initiated and Fostered by Oreste Ghisalba.

Chimia (Aarau) 2020 May;74(5):360-362

Unitectra, Technology Transfer of the Universities of Basel, Bern and Zurich, Scheuchzerstrasse 21, CH-8006 Zurich, Switzerland;, Email:

Giving a voice to the small- and medium-sized biotech enterprises (SME) and putting Swiss biotechnology on the World map were important goals of Oreste Ghisalba when conceiving the Swiss Biotech Association (SBA). The SBA foundation was supported by the technology transfer office (TTO) Unitectra, which Ghisalba also initiated and which was instrumental in his endeavors to foster the collaboration between Swiss universities and the private sector. Laying the foundations for both the SBA and for Unitectra are major achievements of this visionary thinker. Read More

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http://dx.doi.org/10.2533/chimia.2020.360DOI Listing

Development of Swiss Biotechnology Beyond the Biopharmaceutical Sector .

Chimia (Aarau) 2020 May;74(5):345-359

NC Health Sciences, 1, rue Charles-Clos Olsommer, CH-3968 Veyras.

Although diverse, the potential business opportunities for biotechnology outside the biopharmaceutical market are very large. White biotechnology can offer sustainable operations and products, while investments tend to be lower than those in red biotechnology. But a number of bottlenecks and roadblocks in Switzerland must be removed to realise the full potential of white biotechnology. Read More

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http://dx.doi.org/10.2533/chimia.2020.345DOI Listing

The Swiss Industrial Biocatalysis Consortium (SIBC): Past, Present and Future.

Authors:
Steven Hanlon

Chimia (Aarau) 2020 May;74(5):342-344

F. Hoffmann-La Roche Ltd, Department of Process Chemistry and Catalysis, Grenzacherstrasse, CH-4070, Basel, Switzerland;, Email:

Since its inception in 2004, the Swiss Industrial Biocatalysis Consortium (SIBC) has brought together scientists from the Pharma, Fine Chemicals, Agrochemicals and Flavor and Fragrance Industries with the goal of promoting biocatalysis inside and outside of Switzerland as well as providing mutual benefits in the form of pre-competitive knowledge sharing. One of the 'founding fathers' of the SIBC was of course Oreste Ghisalba, whom we are honoring here in this special edition. The history of the SIBC as well as current activities and future challenges will be presented. Read More

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http://dx.doi.org/10.2533/chimia.2020.342DOI Listing

Dedicated, Persistent, Knowledgeable, Visionary and Smart: Dr. Oreste Ghisalba Helped Leverage the Great Potential of Biotechnology to the Benefit of Switzerland.

Chimia (Aarau) 2020 May;74(5):338-341

Swiss Biotech Association, swissbiotech.org.

Oreste Ghislaba's powerful vision and actions to make Switzerland a world-leading hub in biotechnology are described. He recognised the great potential for innovation in biotechnology and was able to communicate this to stakeholders in academia, industry and politics. He was instrumental in the creation of organisations such as Swiss Biotech Association, the CTI, the SATW, TA-Swiss, and the Swiss Industrial Biocatalysis Consortium that helped to create the Swiss biotech hub. Read More

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http://dx.doi.org/10.2533/chimia.2020.338DOI Listing

Building Bridges between Biotechnology and Chemistry - Oreste Ghisalba's Pioneering Activities, Publications and Programs.

Chimia (Aarau) 2020 May;74(5):322-337

Swiss Coordination Committee on Biotechnology (SKB), Nordstrasse 2, CH-8021 Zurich, Switzerland; Lodz University of Technology, Institute of Molecular and Industrial Biotechnology, Stefanowskiego Street 4/10, 90-924 Lodz, Poland; , Email:

This contribution focusses on Oreste Ghisalba's pioneering activities in both fundamental as well as applied research in biocatalysis and his work on building bridges not only between biotechnology and chemistry, but also culturally, geographically and between academia and industry. His scientific work published in journals, books and conferences will be reviewed and his teaching at ETH Zurich and the University of Basel will be highlighted. Furthermore, an appreciation will be given of his broad knowledge and vision in shaping the activities of the Swiss Coordination Committee Biotechnology (SKB), the Swiss-Japanese Meetings in Biotechnology, conferences and research programs such as the Swiss Priority Program Biotechnology (SPP Biotech) of the Swiss National Science Foundation. Read More

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http://dx.doi.org/10.2533/chimia.2020.322DOI Listing

Oreste Ghisalba at the Heart of Biotechnology.

Authors:
Beda M Stadler

Chimia (Aarau) 2020 May;74(5):320-321

Chairman of the Board, Expertinova AG, Birchstrasse 150, CH-8156 Oberhasli, Switzerland;, Email:

A personal account of the author's relationship with Oreste Ghisalba over a period of almost 30 years is given. Read More

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http://dx.doi.org/10.2533/chimia.2020.320DOI Listing

Editorial.

Chimia (Aarau) 2020 May;74(5):317

University of Applied Sciences and Arts Western Switzerland HES SO.

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2 Anglo-Swiss Symposium on 'Using Chemical Biology to Identify New Targets for Medicinal Chemistry', Basel, 4 February, 2020.

Chimia (Aarau) 2020 Apr;74(4):303-304

Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratory of Therapeutic Proteins and Peptides, BCH 5201, Av. F.-A. Forel 2, CH-1015 Lausann;, Email:

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http://dx.doi.org/10.2533/chimia.2020.303DOI Listing

Eloxieren und Färben von Kugelschreiberhülsen.

Authors:
Rita Oberholzer

Chimia (Aarau) 2020 Apr;74(4):300-302

Kantonsschule Im Lee, Rychenbergstrasse 140, CH-8400 Winterthur;, Email:

Es wird ein motivierendes Experiment zur Anwendung des Eloxal-Verfahrens beschrieben. Read More

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http://dx.doi.org/10.2533/chimia.2020.300DOI Listing

Structure Elucidation of a Cryptic Condensation Product from Diacetyl and Arylamine - Then and Now.

Authors:
Lukas Hintermann

Chimia (Aarau) 2020 Apr;74(4):293-297

Department Chemie, Technische Universität München, Lichtenbergstraße 4, 85748 Garching bei München, Germany; TUM Catalysis Research Center, Ernst-Otto-Fischer-Straße 1, 85748 Garching bei München, Germany;, Email:

Some 70 years ago, the reaction of diacetyl (1) and arylamines (2) in hot phosphoric acid was reported to give a new type of condensation products, but no structure was assigned to them. The case is presented to recapitulate the methods and rationales used in classical structure elucidation of organic molecules through reaction networks, before spectroscopic or crystallographic methods were generally available. The difficulties and limits of the classical approach are exemplified through this real-life problem, which could not be solved by the methodology of its time. Read More

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http://dx.doi.org/10.2533/chimia.2020.293DOI Listing

Voltammetric Tracing of Al(III) Using Supramolecular Metal-Polyphenolic Nanofilms Obtained Electrochemically Assisted Self-Assembly.

Chimia (Aarau) 2020 Apr;74(4):289-292

University of Strasbourg, CNRS, Institut Charles Sadron, UPR 22, 67034 Strasbourg, France;, Email:

Supramolecular metal-polyphenolic thin sensor films represent a unique class of composite materials. Their properties and sensitivity can be easily modified controlled self-assembly of their molecular components. Among the different assembly methods, electrochemically triggered processes are extremely powerful because they allow spatial confinement of the film buildup an electrical stimuli-controlled process. Read More

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http://dx.doi.org/10.2533/chimia.2020.289DOI Listing

Spectroscopy of Highly Excited States of the Hydrogen Atom.

Chimia (Aarau) 2020 Apr;74(4):285-288

ETH Zurich, Laboratory of Physical Chemistry, Vladimir-Prelog-Weg 2, CH-8093 Zurich, Switzerland;, Email:

In this contribution, we describe the status of the development of a precision-spectroscopic experiment aimed at measuring transitions to states of high principal quantum number of the hydrogen atom (H). These states form series (called Rydberg series) which converge for → ∞ to the ionization threshold of H. The ionization energy of H can thus be determined directly by measuring the frequencies of transitions to high- states and extrapolating the Rydberg series to → ∞. Read More

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http://dx.doi.org/10.2533/chimia.2020.285DOI Listing

Modular Chiral -Heterocyclic Carbene Ligands for the Nickel-Catalyzed Enantioselective C-H Functionalization of Heterocycles.

Chimia (Aarau) 2020 Apr;74(4):278-284

Ecole Polytechnique Fédérale de Lausanne, EPFL SB ISIC LCSA, BCH 4305, CH-1015 Lausanne;, Email:

-Heterocyclic carbenes (NHCs) are the ligands of choice in a large variety of transformations entailing different transition metals. However, the number and variety of chiral NHCs suitable as stereo-controlling ligands in asymmetric catalysis remains limited. Herein we highlight the introduction of a modular NHC ligand family, consisting of a chiral version of the widely used IPr ligand. Read More

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http://dx.doi.org/10.2533/chimia.2020.278DOI Listing

Exploring the Ubiquitin-Proteasome System (UPS) through PROTAC Technology.

Chimia (Aarau) 2020 Apr;74(4):274-277

School of Pharmaceutical Sciences, University of Geneva, Rue Michel-Servet 1, CH-1206 Geneva;, Email:

In the context of dysregulated ubiquitylation, the accumulation of oncogenic substrates can lead to tumorigenesis. In particular, mutations in Von Hippel-Lindau (VHL) E3 ubiquitin ligase are related to overexpression of hypoxia-inducible factors (HIF-1α and HIF-2α) which is evolving into renal cell carcinoma (RCC). The classical approach of drug discovery focuses on the development of highly selective small molecules able to bind and to inhibit enzymatic active sites. Read More

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http://dx.doi.org/10.2533/chimia.2020.274DOI Listing

Recent Advances in Mode of Action and Biosynthesis Studies of the Clinically Used Antibiotic Fidaxomicin.

Chimia (Aarau) 2020 Apr;74(4):270-273

University of Zurich, Department of Chemistry, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland;, Email:

The natural product antibiotic fidaxomicin is a marketed drug for the treatment of bacterial infections in the gut. Due to its promising activities against , the development of next generation fidaxomicin analogs is of great interest. This article reviews the most recent advances, including the elucidation of a unique mode of action by cryo-EM structures, and the efforts towards the clarification of the biosynthetic pathway. Read More

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http://dx.doi.org/10.2533/chimia.2020.270DOI Listing

Two-dimensional Material Membranes for Gas Separation.

Chimia (Aarau) 2020 Apr;74(4):263-269

Laboratory of Advanced Separations (LAS), École Polytechnique Fédérale de Lausanne (EPFL), Valais, Switzerland;, Email:

Two-dimensional (2D) materials with atom- or few-atoms-thick layers have emerged as building-blocks in the synthesis of the next-generation membrane-based separations. Generally, 2D material-based membranes display high permeation and high selectivity due to their unique structure composed of nanopores and nanochannels with extremely short transport pathways. In this review, the latest advances and ground-breaking research studies on 2D nanosheets for gas separation are highlighted with a focus on the different strategies in synthesizing 2D nanosheets, their assembly into thin membranes and the type of transport mechanism taking place in such membranes. Read More

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http://dx.doi.org/10.2533/chimia.2020.263DOI Listing

Development of In₂O₃-based Catalysts for CO₂-based Methanol Production.

Chimia (Aarau) 2020 Apr;74(4):257-262

Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 1, CH-8093 Zurich, Switzerland;, Email:

CO₂ valorization into chemicals and fuels is a key area in current academic and industrial research, with thermocatalytic hydrogenation to methanol comprising one of the most advanced routes. Life-cycle analysis coupled to the framework of planetary boundaries has recently confirmed the sustainability of this process in absolute terms, emphasizing the need for cheaper CO₂ and renewable H₂ and for a catalytic system embracing high activity, selectivity, and durability to meet economic requirements. Herein, our research efforts aimed to gather atomic-level understanding of electronic and geometric properties of active sites in breakthrough In₂O₃-based catalytic systems guiding their development are reviewed. Read More

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http://dx.doi.org/10.2533/chimia.2020.257DOI Listing

Metal-Salen-based Probes for the Selective Detection of Phosphates a Disassembly Approach.

Chimia (Aarau) 2020 Apr;74(4):252-256

University of Zurich, Winterthurerstrasse 190 , CH-8057 Zurich, Switzerland;, Email:

Polyoxophosphates are ubiquitous in nature and play important roles in biological systems and in the environment. Pyrophosphate (PPi), an important member of this family, is produced in over 200 biochemical reactions and is a marker in clinical diagnosis. In addition to its endogenous role, PPi alias E450 is currently used as preservative, emulsifier or taste intensifier in foodstuff. Read More

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http://dx.doi.org/10.2533/chimia.2020.252DOI Listing

The Serendipitous Discovery of a Rose Odorant.

Chimia (Aarau) 2020 Apr;74(4):247-251

Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 3, CH-8093 Zurich, Switzerland;, Email:

Serendipity has played a role in many groundbreaking scientific discoveries. Key to their identification and exploitation is the ability to recognize the unexpected and invest time trying to understand it. Like any other field of scientific research, total synthesis requires determination and perseverance. Read More

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http://dx.doi.org/10.2533/chimia.2020.247DOI Listing

The Generated Databases (GDBs) as a Source of 3D-shaped Building Blocks for Use in Medicinal Chemistry and Drug Discovery.

Chimia (Aarau) 2020 Apr;74(4):241-246

Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland;, Email:

Drug discovery is in constant need of new molecules to develop drugs addressing unmet medical needs. To assess the chemical space available for drug design, our group investigates the generated databases (GDBs) listing all possible organic molecules up to a defined size, the largest of which is GDB-17 featuring 166.4 billion molecules up to 17 non-hydrogen atoms. Read More

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http://dx.doi.org/10.2533/chimia.2020.241DOI Listing

Molecular Approach to Generate Cu(II) Sites on Silica for the Selective Partial Oxidation of Methane.

Chimia (Aarau) 2020 Apr;74(4):237-240

Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 1-5, CH-8093 Zurich, Switzerland;, Email:

The selective partial oxidation of methane to methanol remains a great challenge in the field of catalysis. Cu-exchanged zeolites are promising materials, directly and selectively converting methane to methanol with high yield under cyclic conditions. However, the economic viability of these aluminosilicate materials for potential industrial applications remains a challenge. Read More

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http://dx.doi.org/10.2533/chimia.2020.237DOI Listing

Learning (from) the Electron Density: Transferability, Conformational and Chemical Diversity.

Chimia (Aarau) 2020 Apr;74(4):232-236

Laboratory for Computational Molecular Design, Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland;, Email:

Machine-learning in quantum chemistry is currently booming, with reported applications spanning all molecular properties from simple atomization energies to complex mathematical objects such as the many-body wavefunction. Due to its central role in density functional theory, the electron density is a particularly compelling target for non-linear regression. Nevertheless, the scalability and the transferability of the existing machine-learning models of ρ(r) are limited by its complex rotational symmetries. Read More

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http://dx.doi.org/10.2533/chimia.2020.232DOI Listing

Probing the Electronic Structure of Spectator Oxo Ligands by O NMR Spectroscopy.

Chimia (Aarau) 2020 Apr;74(4):225-231

Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 1-5, CH-8093 Zurich, Switzerland;, Email:

Spectator oxo ligands are ubiquitous in catalysis, in particular in olefin epoxidation and olefin metathesis. Here we use computationally derived O NMR parameters to probe the electronic structure of spectator oxo ligands in these two reactions. We show that O NMR parameters allow to distinguish between doubly-bonded and triply-bonded oxo ligands, giving detailed insights into the frontier molecular orbitals involved in the metaloxo bonds along the reaction pathway. Read More

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http://dx.doi.org/10.2533/chimia.2020.225DOI Listing

The Gap Sampler: A Versatile Microfluidic Autosampler for Electrospray Ionization Mass Spectrometry.

Authors:
Jérôme Kaeslin

Chimia (Aarau) 2020 Apr;74(4):220-224

ETH Zurich, Vladimir-Prelog-Weg 3, CH-8093 Zurich, Switzerland;, Email:

Microfluidic autosamplers for electrospray ionization mass spectrometry (ESI-MS) are of major importance when using ESI-MS as a high-throughput and low sample consumption analytical method. In this article, microfluidic ESI-MS autosampler designs are overviewed and a group-owned prototype is discussed. The socalled gap sampler is a pin-based sampler for miniaturized flow injection (FI) analysis. Read More

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http://dx.doi.org/10.2533/chimia.2020.220DOI Listing

Editorial.

Chimia (Aarau) 2020 Apr;74(4):217

University of Zurich.

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Novel Multi-phase Materials Combining High Viscoelastic Loss and High Stiffness.

Chimia (Aarau) 2020 Feb;74(1):59

Department of Materials, ETH Zürich, 8093 Zürich, Switzerland;, Email:

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http://dx.doi.org/10.2533/chimia.2020.59DOI Listing
February 2020