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Dr. Tanya K. Ronson Chandan Giri Dr. N. Kodiah Beyeh Antti Minkkinen Filip Topić Dr. Julian J. Holstein Prof. Kari Rissanen Dr. Jonathan R. Nitschke 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(10):3374-3382
Subtle differences in metal–ligand bond lengths between a series of [M4L6]4? tetrahedral cages, where M=FeII, CoII, or NiII, were observed to result in substantial differences in affinity for hydrophobic guests in water. Changing the metal ion from iron(II) to cobalt(II) or nickel(II) increases the size of the interior cavity of the cage and allows encapsulation of larger guest molecules. NMR spectroscopy was used to study the recognition properties of the iron(II) and cobalt(II) cages towards small hydrophobic guests in water, and single‐crystal X‐ray diffraction was used to study the solid‐state complexes of the iron(II) and nickel(II) cages. 相似文献
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Philipp Bissinger Prof. Dr. Holger Braunschweig Dr. Alexander Damme Dr. Rian D. Dewhurst Dr. Katharina Kraft Thomas Kramer Dr. Krzysztof Radacki 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(40):13402-13407
The synthesis of base‐stabilized boryl and borylene complexes is reported. An N‐heterocyclic carbene (NHC)‐stabilized iron–dihydroboryl complex was prepared by two different routes including methane liberation and salt elimination. A range of base‐stabilized iron–dichloroboryl complexes was prepared by addition of Lewis bases to boryl complexes. Base‐stabilized, cationic monochloroborylene complexes were synthesized from these boryl complexes by halide abstraction by using weakly coordinating anions. 相似文献
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Colm Browne Tanya K. Ronson Jonathan R. Nitschke 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2014,126(40):10877-10881
The reaction of 2,6‐diformylpyridine with diverse amines and PdII ions gave rise to a variety of metallosupramolecular species, in which the PdII ion is observed to template a tridentate bis(imino)pyridine ligand. These species included a mononuclear complex as well as [2+2] and [3+3] macrocycles. The addition of pyridine‐containing macrocyclic capping ligands allows for topological complexity to arise, thereby enabling the straightforward preparation of structures that include a [2]catenane, a [2]rotaxane, and a doubly threaded [3]rotaxane. 相似文献
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Common material models that take into account softening effects due to damage encounter the problem of ill-posed boundary value problems if no regularization is applied. This condition leads to a non-unique solution for the resulting algebraic system and a strong mesh dependence of the numerical results. A possible solution approach to prevent this problem is to apply regularization techniques that take into account the non-local behavior of the damage [1]. For this purpose a field function is used to couple the local damage parameter to a non-local level, in which differences between the local and non-local parameter as well as the gradient of the non-local parameter can be penalized. In contrast, we present a novel approach to regularization in which no field function is needed [2]. Hereto, the regularization is carried out by means of the divergence of the displacements and no additional quantity is necessary since the displacements are already defined on a non-local level. The idea is that with an increasing value of the damage the element's volume will increase as well. This is a result of the softening due to the occurring damage. The increasing volume can be measured by the divergence of the displacements which can be penalized by an additional energy part. The lack of any field function and the regularization by the use of the divergence of the displacements entails several numerical advantages: the computational effort is considerably reduced and the convergence behavior is improved as well. Naturally, the numerical results are mesh independent due to the regularization. (© 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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Simon Sengupta Philipp Schüler Dr. Helmar Görls Dr. Phil Liebing Dr. Sven Krieck Prof. Matthias Westerhausen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(50):e202201359
The in situ Grignard Metalation Method (iGMM) is a straightforward one-pot procedure to quickly produce multigram amounts of Hauser bases R2N-MgBr which are valuable and vastly used metalation reagents and novel electrolytes for magnesium batteries. During addition of bromoethane to a suspension of Mg metal and secondary amine at room temperature in an ethereal solvent, a smooth reaction yields R2N-MgBr under evolution of ethane within a few hours. A Schlenk equilibrium is operative, interconverting the Hauser bases into their solvated homoleptic congeners Mg(NR2)2 and MgBr2 depending on the solvent. Scope and preconditions are studied, and side reactions limiting the yield have been investigated. DOSY NMR experiments and X-ray crystal structures of characteristic examples clarify aggregation in solution and the solid state. 相似文献
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Candida Manelfi Jonas Gossen Silvia Gervasoni Carmine Talarico Simone Albani Benjamin Joseph Philipp Francesco Musiani Giulio Vistoli Giulia Rossetti Andrea Rosario Beccari Alessandro Pedretti 《Molecules (Basel, Switzerland)》2021,26(4)
The 3CL-Protease appears to be a very promising medicinal target to develop anti-SARS-CoV-2 agents. The availability of resolved structures allows structure-based computational approaches to be carried out even though the lack of known inhibitors prevents a proper validation of the performed simulations. The innovative idea of the study is to exploit known inhibitors of SARS-CoV 3CL-Pro as a training set to perform and validate multiple virtual screening campaigns. Docking simulations using four different programs (Fred, Glide, LiGen, and PLANTS) were performed investigating the role of both multiple binding modes (by binding space) and multiple isomers/states (by developing the corresponding isomeric space). The computed docking scores were used to develop consensus models, which allow an in-depth comparison of the resulting performances. On average, the reached performances revealed the different sensitivity to isomeric differences and multiple binding modes between the four docking engines. In detail, Glide and LiGen are the tools that best benefit from isomeric and binding space, respectively, while Fred is the most insensitive program. The obtained results emphasize the fruitful role of combining various docking tools to optimize the predictive performances. Taken together, the performed simulations allowed the rational development of highly performing virtual screening workflows, which could be further optimized by considering different 3CL-Pro structures and, more importantly, by including true SARS-CoV-2 3CL-Pro inhibitors (as learning set) when available. 相似文献