Structural and Functional Evolution of a Library of Constitutional Dynamic Polymers Driven by Alkali Metal Ion Recognition
作者:Shunsuke Fujii、Jean-Marie Lehn
DOI:10.1002/anie.200902512
日期:2009.9.28
Aptly folded: Dynamic polymer libraries were generated by polycondensation through reversible imine bonds and can undergo driven evolution under the double stimuli of donor–acceptor stacking and metal‐ion binding (see picture). The specific binding modes of alkali metal ions are associated with specific constitutional changes and with different optical natures that reflect the presence and the positions
[2]Pseudorotaxanes and [2]Catenanes Constructed by Oxacalixcrowns/Viologen Molecular Recognition Motifs
作者:Hua Liu、Xiao-Yan Li、Xiao-Li Zhao、Yahu A. Liu、Jiu-Sheng Li、Biao Jiang、Ke Wen
DOI:10.1021/ol502869u
日期:2014.11.21
Oxacalix[2]arene[2]pyrazine and functional polyether derived oxacalixcrown-6, -7, and -8 were synthesized, and their host–guest complexation with paraquat to form [2]pseudorotaxanes was studied. The [2]pseudorotaxanes were then successfully used in the construction of two oxacalixcrown-tetracationic cyclophane [CBPQT4+] based [2]catenanes.
Structural Homology and Dynamic Variation in a Series of Porphyrin Bipyridinium Receptors and Their [2]Catenanes
作者:Maxwell J. Gunter、Tyrone P. Jeynes、Peter Turner
DOI:10.1002/ejoc.200300493
日期:2004.1
We describe the successful synthesis of the porphyrin [2]catenanes, which completes a set of six structures where the length of the polyethylene glycol strap over the porphyrin is regularly increased fromdiethylene to triethylene to tetraethylene, and the central electron-donor component is either hydroquinol- or naphthoquinol-based. In the synthetic route to the strapped porphyrin precursors, co-formation
Molecular Shuttles Based on Tetrathiafulvalene Units and 1,5-Dioxynaphthalene Ring Systems
作者:Seogshin Kang、Scott A. Vignon、Hsian-Rong Tseng、J. Fraser Stoddart
DOI:10.1002/chem.200305725
日期:2004.5.17
rotaxanes contained either two tetrathiafulvalene (TTF) units or two 1,5-dioxynaphthalene (DNP) ringsystems, both of which serve as recognition sites for a cyclobis(paraquat-p-phenylene) (CBPQT4+) ring. Three different spacer units were incorporated into the dumbbell components of the [2]rotaxanes between the recognition sites. They include a polyether chain, a terphenyl unit, and a diphenyl ether linker
A series of neutral porphyrin-containing catenanes has been synthesised, consisting of a zinc porphyrin strapped by a polyethylene glycol chain containing four or six ethylenoxy-units and incorporating a central naphthoquinol unit, interlinked with a naphthalene diimide macrocycle. The napthalene diimide precursor units exhibit only weak binding with the strapped porphyrins (Ka between 8 and 0.02 Mâ1), but good yields of the catenanes were obtained by Glaser coupling of the alkynyl napthalene diimide precursors in the presence of the porphyrins. Structures and solution conformations were determined by mass spectral and detailed 1H NMR studies. For the longer strapped porphyrins, the diimide macrocycle rotates around the central naphthoquinol unit at 420â450 times per second, while rotation is virtually prevented in the tighter strapped derivatives. A second dynamic process occurring in both sets of catenanes and described as âyawingâ leads to inequivalence in the naphthalene moieties. UV-Visible spectra indicate charge transfer interactions and electronic communication between the two components of the catenane.