- Supramolecular assemblies based on Fe8L12 cubic metal-organic cages: Synergistic adsorption and spin-crossover properties
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Two FeII8L12 cubic metal-organic cages were constructed with semi-rigid ligands and they further self-assembled into supramolecular assemblies with three different porous cavities. The supramolecular assemblies showed synergistic adsorption of
- Gong, Yu,Gu, Zhi-Guo,Han, Wang-Kang,Hu, Qing-Tao,Li, Tao,Lu, Hui-Shu,Xu, Ya-Xin,Yan, Xiaodong,Zhang, Hai-Xia
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- Path selection for conformational interconversions in [2]catenanes
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The conformational interconversions of several [2]catenanes containing a dibenzo-34-crown-10 ether (BPP34C10) interlocked with rings containing two 4,4′-dipyridyls tethered by different aryl spacers have been studied. Blocking groups on the tethers enabled the two pathways for circumrotation of the BPP34C10 to be open or blocked. The activation barrier for migration along the open tethers varied from 11 to 13 kcal/mol. This study demonstrates an ability to select the pathway for conformational interconversions in [2]catenanes.
- Halterman, Ronald L.,Martyn, David E.,Pan, Xingang,Ha, Diana B.,Frow, Michael,Haessig, Kathryn
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p. 2119 - 2121
(2007/10/03)
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- Synthesis of Quaternary Salts of Ammonia from Phenols and their Plant Growth Retardant Activity
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Different phenols, viz. β-naphthol, p-chlorophenol, p-cresol and m-nitrophenol have been converted into (3-diethylamino-2-hydroxypropyloxy) derivatives (4a-d) through the formation of glycidyl ethers (2a-d and 3a-d). m-Nitrophenol and p-chlorophenol have been converted to 2-aryloxy-N,N-diethylaminoethanes (8e,f) through the formation of bromoethers (7e,f). 1,3-Bis(2-diethylaminoethoxy)benzene (12) has been prepared from resorcinol. The tertiary amines (4a-d, 8e,f and 12) are then quaternized with citronellyl bromide and tested as plant growth retardants.
- Sharma,Talwar,Duggal, Reema
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p. 381 - 383
(2007/10/03)
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- Self-assembly and self-organization of self-recognizing cyclophanes
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An analysis is presented of the different contributions that give rise to the packing observed in the crystal structures of a wide range of bipyridinium-based molecular assemblies and supramolecular arrays. It is demonstrated how the various interactions - electrostatic, van der Waals, and π-π interactions - that contribute to the solid-state arrangement of these molecules and supermolecules can be utilized in order to design a series of tetracationic cyclophanes that can potentially self-organize in a highly ordered way in the solid state by virtue of the fact that they contain π-electron donors as well as π-electron acceptors. The syntheses of these cyclophanes is outlined and the tunability of the self-assembly methodology in their construction is demonstrated. One of these tetracationic cyclophanes - comprising π-electron-rich hydroquinone rings and π-electron-deficient bipyridinium units - has been shown to pack as highly ordered two-dimensional, mosaic-like sheets in the solid state. Its dicationic precursor also forms extended π-π-stacked layers in the solid state. An analogous cyclophane - containing two π-electron-rich resorcinol rings in place of the two hydroquinone rings - forms, in the solid state, one-dimensional arrays wherein the component resorcinol rings interact through then: parallel π-π stacking. It has also been established that the first of the aforementioned tetracationic cyclophanes forms a 1:1 adduct with ferrocene in both the solution and solid states. X-ray crystallography, performed on the 1:1 adduct, reveals that not only is the ferrocene molecule complexed in a π-π slacking sense within the tetracationic cyclophane, but the 1:1 adduct also packs in a manner that is remarkably similar to the supramolecular organization of the free cyclophane in the crystalline state.
- Ashton, Peter R.,Chemin, Alexandre,Claessens, Christian G.,Menzer, Stephan,Stoddart, J. Fraser,White, Andrew J. P.,Williams, David J.
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p. 969 - 981
(2007/10/03)
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