Dr. Stefan Schramm  PD. Dr. Dieter Weiß 《Chemie in Unserer Zeit》2023,57(1):6-19

This article examines terrestrial bioluminescence illustrated by many individual organisms such as the firefly, fungi, snails, worms, and even larvae. For each of the systems, a brief historical, geographical or biological background is given, followed by a discussion of the underlying chemical reactions that are responsible for the light emission. Common to all of them is the reaction of an oxygen-rich intermediate, whose decomposition leads to the generation of electronically excited states of the emitter molecules. Although many terrestrial bioluminescence systems have already been studied, there are still a large number of almost completely unknown systems that are the subject of current research.  相似文献   

    

Dieter Sicker 《Chemie in Unserer Zeit》2020,54(6):402-406

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Nils Keltsch  Viola Munzert  Klaus‐Peter Zeller  Hans‐Ullrich Siehl  Stefan Berger  Dieter Sicker 《Chemie in Unserer Zeit》2019,53(2):92-102

Linderazulene, a crystalline azulene derivative, is violet due to the annulated furan ring and not blue like many other azulenes. Linderazulene occurs naturally in Gorgonians. Some plants form colourless sesquiterpenoid precursors of linderazulene. Their degradation can give rise to linderazulene as an aromatic hydrocarbon, e.g. by steam distillation. The chromatographic isolation of linderazulene in minute amounts from the essential of the seeds of Perfoliate Alexanders (Smyrnium perfoliatum) obtained by steam distillation is described. This attractive plant belongs to Apiaceae and is an invasive species in Germany. All spectra are presented with interpretations. Based on a student's project work this paper is a follow up of the recent book “Classics in Spectroscopy” by S. Berger und D. Sicker (Wiley‐VCH 2009). This is the final chapter of our series on 30 natural products.  相似文献   

    

Dieter Weiß  Eric Tuscher  Herbert Brandl 《Chemie in Unserer Zeit》2019,53(1):12-21

Porphyrins and some of their metal complex salts, for example chlorophylls, hemo‐and myoglobin, play an important role as natural pigments for life on earth. Heme is the prosthetic group of red animal dyestuffs. The chemical structure and the properties of heme, its biosynthesis and decomposition products biliverdin and bilirubin (bilepigments) are described. In nature, biliverdin is found as a dye in green and blue eggshells of some birds and in the green bones of garfish and eelpout. Bilirubin in a too high (pathological) concentration in human blood, causes the symptoms of jaundice, common a problem with infants. The importance of porphyrin chemistry today, is in medical and technical applications. The fascinating experiments contributed in this publication are to inspire young and old chemists in porphyrin chemistry.  相似文献   

    

Christian Schmitz  Yulian Pang  Andr Gülz  Marina Glser  Joachim Horst  Martin Jger  Bernd Strehmel 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(13):4445-4450

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Bing Bai  Meng Xu  Nan Li  Wenxing Chen  Jiajia Liu  Jia Liu  Hongpan Rong  Dieter Fenske  Jiatao Zhang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(15):4906-4911

Thiol‐ and solvent‐coordinated cation exchange kinetics have been applied to engineer the composition and crystallinity of novel nanocrystals. The detailed thermodynamics and kinetics of the reactions were explored by NMR spectroscopy, time‐dependent photoluminescence (PL) characterizations and theoretical simulations. The fine structure of the colloidal semiconductor nanocrystals (CSNCs) was investigated by X‐ray absorption near‐edge structure (XANES) and extended X‐ray absorption fine structure (EXAFS). In this way, high‐quality p‐type Ag‐doped ZnS quantum dots (QDs) and Au@ZnS hetero‐nanocrystals with a cubic phase ZnS shell were synthesized successfully.The unprecedented dominant Ag⁺‐dopant‐induced fluorescence and p‐type conductivity in the zinc‐blende ZnS are reported.  相似文献   

    

Shubham Garg  Heidi Schwartz  Mariana Kozlowska  Anemar Bruno Kanj  Kai Müller  Wolfgang Wenzel  Uwe Ruschewitz  Lars Heinke 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(4):1205-1210

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Maurice Dörr  Sebastian Lips  Prof. Dr. Carlos Alberto Martínez-Huitle  Dr. Dieter Schollmeyer  Prof. Dr. Robert Franke  Prof. Dr. Siegfried R. Waldvogel 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(33):7835-7838

We report an innovative, sustainable and straightforward protocol for the synthesis of N,N-diarylamides equipped with nonprotected hydroxyl groups by using electrosynthesis. The concept allows the application of various substrates furnishing diarylamides with yields up to 57 % within a single and direct electrolytic protocol. The method is thereby easy to conduct in an undivided cell with constant current conditions offering a versatile and short-cut alternative to conventional pathways.  相似文献   

    

Dr. Margot N. Wenzel  Dr. Riccardo Bonsignore  Sophie R. Thomas  Dr. Didier Bourissou  Prof. Giampaolo Barone  Prof. Angela Casini 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(32):7628-7634

With the aim of exploiting the use of organometallic species for the efficient modification of proteins through C-atom transfer, the gold-mediated cysteine arylation through a reductive elimination process occurring from the reaction of cyclometalated Au^III C^N complexes with a zinc finger peptide (Cys₂His₂ type) is here reported. Among the four selected Au^III cyclometalated compounds, the [Au(C^CON)Cl₂] complex featuring the 2-benzoylpyridine (C^CON) scaffold was identified as the most prone to reductive elimination and Cys arylation in buffered aqueous solution (pH 7.4) at 37 °C by high-resolution LC electrospray ionization mass spectrometry. DFT and quantum mechanics/molecular mechanics (QM/MM) studies permitted to propose a mechanism for the title reaction that is in line with the experimental results. Overall, the results provide new insights into the reactivity of cytotoxic organogold compounds with biologically important zinc finger domains and identify initial structure–activity relationships to enable Au^III-catalyzed reductive elimination in aqueous media.  相似文献   

    

Iason Papaioannou  Marco Daub  Martin Drieschner  Fabian Duddeck  Max Ehre  Lukas Eichner  Martin Eigel  Marco Gtz  Wolfgang Graf  Lars Grasedyck  Robert Gruhlke  Dietmar Hmberg  Michael Kaliske  Dieter Moser  Yuri Petryna  Daniel Straub 《GAMM-Mitteilungen》2019,42(2)

Engineers are faced with the challenge of supporting decision making under uncertainty. Engineering decisions often depend on model‐based predictions of the performance of the engineering system of interest. Input uncertainties of models can be categorized into two distinct types: aleatory (random/irreducible) or epistemic (reducible). Polymorphic uncertainty quantification (UQ) can be used to treat aleatory and epistemic uncertainties in a unified framework. The polymorphic UQ framework employs probability theory to model aleatory variables and alternative approaches (interval, fuzzy, Bayesian probabilistic, and combinations thereof) to model epistemic variables. This paper compares different polymorphic UQ approaches with respect to their ability to support a simple engineering decision. The comparison is based on a test‐bed example, whereby aleatory variables are defined in terms of probability distributions and epistemic variables are described based on limited information (sparse data or intervals). Two challenges related to common engineering decisions (safety assessment and reliability‐based design) serve as a basis for the comparison. Five independent research groups applied different models to describe the epistemic parameters based on a subjective interpretation of the given information. The comparison of the results reveals a strong influence of both the subjective choices on the models of the epistemic variables and the chosen basis for assessing the performance of the structure on the obtained decision outcomes.  相似文献