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Anusree Viswanath Kuttatheyil Marcel Handke Jens Bergmann Dr. Daniel Lässig Dr. Jörg Lincke Prof. Dr. Jürgen Haase Dr. Marko Bertmer Prof. Dr. Harald Krautscheid 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(3):1118-1124
Spectroscopic techniques are a powerful tool for structure determination, especially if single‐crystal material is unavailable. 113Cd solid‐state NMR is easy to measure and is a highly sensitive probe because the coordination number, the nature of coordinating groups, and the geometry around the metal ion is reflected by the isotropic chemical shift and the chemical‐shift anisotropy. Here, a detailed investigation of a series of 27 cadmium coordination polymers by 113Cd solid‐state NMR is reported. The results obtained demonstrate that 113Cd NMR is a very sensitive tool to characterize the cadmium environment, also in non‐single‐crystal materials. Furthermore, this method allows the observation of guest‐induced phase transitions supporting understanding of the structural flexibility of coordination frameworks. 相似文献
966.
Dr. Ehsan Ullah Mughal Jens Eberhard Prof. Dr. Dietmar Kuck 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(47):16029-16035
The linear extension of the rigid, C3v‐symmetrical carbon framework of tribenzotriquinacene (TBTQ) along its three wings is reported. The key step of the extension procedure consists of a Diels–Alder reaction of three ortho‐quinodimethane units generated in situ at the triquinacene core. The use of 1,4‐naphthoquinone provides a facile and particularly efficient access to tris(tetraceno)‐annellated triquinacenes. The steady‐state photophysical properties of these new oligotetracenes bearing three mutually orthogonal chomophores are determined and analyzed by DFT calculations. 相似文献
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Elaheh Khozeimeh Sarbisheh Jose Esteban Flores Dr. Jianfeng Zhu Prof. Dr. Jens Müller 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(47):16838-16849
A mixture of cis/trans isomers of phospha[1]ferrocenophanes equipped with one iPr group at the α position to the bridging PhP moiety was prepared. Both isomers (cis‐ 4 and trans‐ 4 ) were obtained as racemates and could be separated so that their thermal properties were investigated individually. The molecular structure of cis‐ 4 was determined by single‐crystal X‐ray analysis showing a tilt angle α=26.35(8)°. Interconversion between both isomers occurred in the melt at elevated temperatures and revealed that the trans isomer is thermodynamically more stable. Structural and thermodynamic data was complemented by DFT calculations (B3PW91/6‐311+G(d,p) and B3PW91‐D3(BJ)/6‐311+G(d,p)). Performance of thermal ring‐opening polymerization (ROP) of trans‐ 4 at 230 °C gave polymers and cyclic oligomers. Gel permeation chromatography (GPC) of the sulfurized polymer resulted in a molecular weight of 62.5 kDa (Mw) and a polydispersity index of 1.39 (PDI). Mass spectrometric analysis of the oligomers showed the presence of cyclic species from dimers to heptamers. After sulfurization, preparative thin layer chromatography led to the separation of three isomeric dimers. Structural characterization of these dimers by single‐crystal X‐ray analysis led to the conclusion that the Fe?Cp bond breaks during the thermal ROP process. A mechanism similar to the known mechanism of the photolytic ROP of ferrocenophanes is proposed. 相似文献
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Jenny Barbier Dr. Rolf Jansen Dr. Herbert Irschik Dr. Stefan Benson Dr. Klaus Gerth Bettina Böhlendorf Prof. Dr. Gerhard Höfle Prof. Dr. Hans Reichenbach Jens Wegner Dr. Carsten Zeilinger Prof. Dr. Andreas Kirschning Prof. Dr. Rolf Müller 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2012,124(5):1282-1286
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