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Liu P.,Nanjing UniversityNanjing210093 Peoples Republic of China | Ma J.,Key Laboratory of Mesoscopic Chemistry of MOE
Journal of Computational Chemistry | Year: 2016

An electrostatic potential (ESP)-based image segmentation method has been used to estimate the ability of proton donation and acceptance involved in ring-rod recognition. The relative binding strength of [2]rotaxane has also been further estimated from the difference of the characteristic image-segmentation derived ESP between proton donor and proton acceptor. The size and electrostatic compatibility criteria are introduced to guide the design of interlocked [2]rotaxane. A library of 75 thermodynamically stable [2]rotaxane candidates has been generated, including 16 experimentally known systems. The theoretical results for 16 experimentally known [2]rotaxanes are in good agreement with both the experimental association constants and density functional theory-calculated binding energies. Our ESP-based image segmentation model is also applicable to the tristable [2]rotaxane molecular shuttle as well as [1]rotaxane with self-inclusion function, indicating this simple method is generic in the field of constructing other supramolecular architectures formed with donor/acceptor molecular recognition. © 2016 Wiley Periodicals, Inc. Source

Erste A.,Jozef Stefan Institute | Chen X.-Z.,Key Laboratory of Mesoscopic Chemistry of MOE | Jia C.-L.,Key Laboratory of Mesoscopic Chemistry of MOE | Shen Q.-D.,Key Laboratory of Mesoscopic Chemistry of MOE | Bobnar V.,Jozef Stefan Institute
Ferroelectrics | Year: 2012

Properties of newly-developed relaxor reduced poly(vinylidene fluoride-trifluoroethylene) copolymer have been investigated by measurements of temperature and frequency dependent dielectric response in dc bias electric field. It has been found that dc bias field effectively blocks the ac conductivity. The analysis of dielectric dynamics show that the Vogel-Fulcher parameters, obtained from either peaks in ε″(T) or frequency dependent dielectric data, are identical within experimental error. Furthermore, the decrease of Vogel-Fulcher temperature and increase of activation energy on increasing dc bias field suggest that the nonlinear dielectric susceptibility dominantly influences the relaxor dynamics in dc bias electric fields. Copyright © Taylor & Francis Group, LLC. Source

Dong L.,Key Laboratory of Mesoscopic Chemistry of MOE | Zhang L.,Key Laboratory of Mesoscopic Chemistry of MOE | Sun C.,Key Laboratory of Mesoscopic Chemistry of MOE | Yu W.,Key Laboratory of Mesoscopic Chemistry of MOE | And 8 more authors.
ACS Catalysis | Year: 2011

CuO/VOx/Ti0.5Sn0.5O2 catalysts were prepared by an impregnation method and were tested on a NO + CO model reaction. Both copper oxide and vanadium oxide can be highly dispersed on Ti0.5Sn0.5O2 (denoted as TS, hereafter) support. The dispersed oxides form V-O-Cu species when coexisting in the catalyst system. The formation of V-O-Cu species renders the dispersed vanadium oxide aggregated and easier to be reduced; in contrast, the reduction temperature of dispersed copper oxide species is evidently higher than that without vanadium oxide (CuO/TS samples). The surface dispersed V-O-Cu species are mainly the active component for the NO + CO reaction. The activities of CuO/VOx/TS catalysts are highly dependent on the operating temperature and the amount of V-O-Cu species. In the reaction atmosphere, NO molecules are adsorbed onto Cu2+ sites, reduced Vx+ (V4+ or V3+) sites, and even TS support, forming -NO and NO3 - species. Adsorption of CO molecules proceeds only on Cu+ sites. The active species change with varying reaction temperature; hence, the NO + CO reaction goes through different mechanisms at low and high temperatures over these catalysts. © 2011 American Chemical Society. Source

Tao D.-J.,Nanjing University | Tao D.-J.,Key Laboratory of Mesoscopic Chemistry of MOE | Zhou Z.,Nanjing University | Zhou Z.,Key Laboratory of Mesoscopic Chemistry of MOE | And 6 more authors.
Xiandai Huagong/Modern Chemical Industry | Year: 2011

The application and research progress in the esterification reactions are reviewed using ionic liquids as green catalysts. The problems existing in the catalysis of ionic liquids are also discussed, and some suggestions on the solution of these issues are put forward. Source

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