排序方式: 共有44条查询结果,搜索用时 15 毫秒
41.
Dipl.‐Chem. Rainer Hovorka Dipl.‐Chem. Georg Meyer‐Eppler Dipl.‐Chem. Torsten Piehler Sophie Hytteballe Dr. Marianne Engeser Filip Topić Prof. Dr. Kari Rissanen Prof. Dr. Arne Lützen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(41):13253-13258
Two enantiomerically pure 9,9′‐spirobifluorene‐based bis(pyridine) ligands 1 and 2 were prepared to study their self‐assembly behavior upon coordination to cis‐protected palladium(II) ions. Whereas the sterically more demanding ligand, 2 , gave rise to the expected dinuclear metallosupramolecular M2L2 rhombi, the sterically less demanding ligand, 1 , acts as a template to give rise to a homochiral metallosupramolecular M4L4 catenane. 相似文献
42.
Dr. Christoph Gütz Dipl.‐Chem. Rainer Hovorka M. Sc. Christoph Klein M. Sc. Qian‐Qian Jiang M. Sc. Christoph Bannwarth Dr. Marianne Engeser Prof. Dr. Carsten Schmuck Dr. Wilfried Assenmacher Prof. Dr. Werner Mader M. Sc. Filip Topić Prof. Dr. Kari Rissanen Prof. Dr. Stefan Grimme Prof. Dr. Arne Lützen 《Angewandte Chemie (International ed. in English)》2014,53(6):1693-1698
Coordination‐driven self‐assembly is one of the most powerful strategies to prepare nanometer‐sized discrete (supra)molecular assemblies. Herein, we report on the use of two constitutionally isomeric BINOL‐based bis(pyridine) ligands for this purpose. Upon coordination to PdII ions these self‐assemble into enantiomerically pure endo‐ and exo‐functionalized hexa‐ and dodecanuclear metallosupramolecular spheres with a chiral skeleton depending on the substitution pattern of the BINOL core. These aggregates were characterized by NMR, MS, DLS, TEM, and EELS as well as ECD. Furthermore, experimental ECD data could be compared to those obtained from theoretical simulations using a simplified Tamm–Dancoff approximation to time‐dependent DFT to rationalize the extraordinary high molar circular dichroisms. Despite the rotational freedom around the central aryl–aryl bond of these ligands, the self‐assembly process happens completely selective in a “narcissistic” self‐recognition manner. 相似文献
43.
This paper is devoted to the approximate solution of a strongly NP-hard resource-constrained scheduling problem which arises in relation to the operability of certain high availability real
time distributed systems. We present an algorithm based on the simulated annealing metaheuristic and, building on previous
research on exact solution methods, extensive computational results demonstrating its practical ability to produce acceptable
solutions, in a precisely defined sense. Additionally, our experiments are in remarkable agreement with certain theoretical
properties of our simulated annealing scheme. The paper concludes with a short discussion on further research.
This research was supported in part by Association Nationale de la Recherche Technique grant CIFRE-121/2004. 相似文献
44.
Dr. Luzia S. Germann Dr. Elvio Carlino Dr. Antonietta Taurino Dr. Oxana V. Magdysyuk Prof. Dario Voinovich Dr. Robert E. Dinnebier Dr. Dejan-Krešimir Bučar Dr. Dritan Hasa 《Angewandte Chemie (International ed. in English)》2023,62(19):e202212688
Crystal engineering has exclusively focused on the development of advanced materials based on small organic molecules. We now demonstrate how the cocrystallization of a polymer yields a material with significantly enhanced thermal stability but equivalent mechanical flexibility. Isomorphous replacement of one of the cocrystal components enables the formation of solid solutions with melting points that can be readily fine-tuned over a usefully wide temperature range. The results of this study credibly extend the scope of crystal engineering and cocrystallization from small molecules to polymers. 相似文献