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Dr. Ritesh Haldar Kamal Batra Stefan Michael Marschner Dr. Agnieszka B. Kuc Dr. Stefan Zahn Prof. Dr. Roland A. Fischer Prof. Dr. Stefan Bräse Prof. Dr. Thomas Heine Prof. Dr. Christof Wöll 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(33):7847-7851
In organic photovoltaics, porphyrins (PPs) are among the most promising compounds owing to their large absorption cross-section, wide spectral range, and stability. Nevertheless, a precise adjustment of absorption band positions to reach a full coverage of the so-called green gap has not been achieved yet. We demonstrate that a tuning of the PP Q- and Soret bands can be carried out by using a computational approach for which substitution patterns are optimized in silico. The most promising candidate structures were then synthesized. The experimental UV/Vis data for the solvated compounds were in excellent agreement with the theoretical predictions. By attaching further functionalities, which allow the use of PP chromophores as linkers for the assembly of metal-organic frameworks (MOFs), we were able to exploit packing effects resulting in pronounced redshifts, which allowed further optimization of the photophysical properties of PP assemblies. Finally, we use a layer-by-layer method to assemble the PP linkers into surface-mounted MOFs (SURMOFs), thus obtaining high optical quality, homogeneous and crystalline multilayer films. Experimental results are in full accord with the calculations, demonstrating the huge potential of computational screening methods in tailoring MOF and SURMOF photophysical properties. 相似文献
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Dr. Sabin Llona‐Minguez Dr. Matthieu Desroses Artin Ghassemian Dr. Sylvain A. Jacques Dr. Lars Eriksson Rebecka Isacksson Tobias Koolmeister Dr. Pål Stenmark Dr. Martin Scobie Prof. Thomas Helleday 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(20):7394-7398
A two‐step synthesis of structurally diverse pyrrole‐containing bicyclic systems is reported. ortho‐Nitro‐haloarenes coupled with vinylic N‐methyliminodiacetic acid (MIDA) boronates generate ortho‐vinyl‐nitroarenes, which undergo a “metal‐free” nitrene insertion, resulting in a new pyrrole ring. This novel synthetic approach has a wide substrate tolerance and it is applicable in the preparation of more complex “drug‐like” molecules. Interestingly, an ortho‐nitro‐allylarene derivative furnished a cyclic β‐aminophosphonate motif. 相似文献
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Electrically Switchable Magnetic Molecules: Inducing a Magnetic Coupling by Means of an External Electric Field in a Mixed‐Valence Polyoxovanadate Cluster 下载免费PDF全文
Dr. Salvador Cardona‐Serra Dr. Juan M. Clemente‐Juan Prof. Eugenio Coronado Dr. Alejandro Gaita‐Ariño Dr. Nicolas Suaud Dr. Ondrej Svoboda Dr. Roland Bastardis Prof. Nathalie Guihéry Dr. Juan J. Palacios 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(2):763-769
Herein we evaluate the influence of an electric field on the coupling of two delocalized electrons in the mixed‐valence polyoxometalate (POM) [GeV14O40]8? (in short V14) by using both a t‐J model Hamiltonian and DFT calculations. In absence of an electric field the compound is paramagnetic, because the two electrons are localized on different parts of the POM. When an electric field is applied, an abrupt change of the magnetic coupling between the two delocalized electrons can be induced. Indeed, the field forces the two electrons to localize on nearest‐neighbors metal centers, leading to a very strong antiferromagnetic coupling. Both theoretical approaches have led to similar results, emphasizing that the sharp spin transition induced by the electric field in the V14 system is a robust phenomenon, intramolecular in nature, and barely influenced by small changes on the external structure. 相似文献
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Theodore Flack Thibaut Constantin Sylvain Penasse Dr. Jérôme Dejeu Béatrice Gennaro Dr. Muriel Jourdan Aurélien Laguerre Marc Pirrotta Dr. David Monchaud Dr. Nicolas Spinelli Prof. Eric Defrancq 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(5):1760-1767
A water‐soluble template‐assembled synthetic G‐quartet (TASQ) based on the use of a macrocyclodecapeptide scaffold was designed to display stable intramolecular folds alone in solution. The preformation of the guanine quartet, demonstrated by NMR and CD investigations, results in enhanced peroxidase‐type biocatalytic activities and improved quadruplex‐interacting properties. Comparison of its DNAzyme‐boosting properties with the ones of previously published TASQ revealed that, nowadays, it is the best DNAzyme‐boosting agent. 相似文献
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Measurement of oxygen isotope ratios (18O/16O) of aqueous O2 in small samples by gas chromatography/isotope ratio mass spectrometry 下载免费PDF全文
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Reassessment of the NH4NO3 thermal decomposition technique for calibration of the N2O isotopic composition 下载免费PDF全文
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Pradip Ghosh Roland Schoch Matthias Bauer Axel Jacobi von Wangelin 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2022,134(1):e202110821
Metal-catalyzed C?H activations are environmentally and economically attractive synthetic strategies for the construction of functional molecules as they obviate the need for pre-functionalized substrates and minimize waste generation. Great challenges reside in the control of selectivities, the utilization of unbiased hydrocarbons, and the operation of atom-economical dehydrocoupling mechanisms. An especially mild borylation of benzylic CH bonds was developed with the ligand-free pre-catalyst Co[N(SiMe3)2]2 and the bench-stable and inexpensive borylation reagent B2pin2 that produces H2 as the only by-product. A full set of kinetic, spectroscopic, and preparative mechanistic studies are indicative of a tandem catalysis mechanism of CH-borylation and dehydrocoupling via molecular CoI catalysts. 相似文献