[4]Pseudorotaxanes with Remarkable Self-Sorting Selectivities
作者:Wei Jiang、Dominik Sattler、Kari Rissanen、Christoph A. Schalley
DOI:10.1021/ol201618f
日期:2011.9.2
The synthesis and characterization of several self-assembled [4]pseudorotaxanes is reported, some of which form in a programmed way based on two similar yet orthogonal crown ether/secondary ammonium ion binding motifs. A preference for the formation of a [4]pseudorotaxane with an antiparallel rather than parallel alignment of crown ether building blocks is observed even in the absence of such orthogonal binding sites, when a homodivalent axle is used.
Monitoring Self-Sorting by Electrospray Ionization Mass Spectrometry: Formation Intermediates and Error-Correction during the Self-Assembly of Multiply Threaded Pseudorotaxanes
作者:Wei Jiang、Andreas Schäfer、Parveen Choudhary Mohr、Christoph A. Schalley
DOI:10.1021/ja9101369
日期:2010.2.24
Three binary pseudorotaxanes, which are based on two different secondary ammonium/crown ether binding motifs, have been studied by H-1 NMR and H-1,H-1 EXSY NMR experiments with respect to their thermodynamic stabilities and their axle exchange kinetics. The stability ranking does not follow the order of axle exchange rates, and the thermodynamically most stable axle-wheel combinations assemble only slowly On the basis of these binding motifs, a series of self-sorting systems have been studied ranging from simple four-component mixtures through sequence-specific pseudorotaxanes to multiply threaded complexes Because of the mismatch of kinetic and thermodynamic order, wrongly assembled structures are unavoidable, which require error-correction steps to yield the final thermodynamically controlled self-sorted products. These error-correction steps can easily be monitored by electrospray mass spectrometry, when a mixed-flow microreactor is coupled to the ion source to cover second time scales Self-assembly intermediates, wrongly assembled structures, and the final thermodynamic products can be simultaneously identified The determination of preferred assembly pathways as well as the formation of dead-end structures provides a clear picture of a rich kinetic behavior of the self-sorting systems under study
Photooxygenation and gas-phase reactivity of multiply threaded pseudorotaxanes
作者:Karol Nowosinski、Stephan Warnke、Kevin Pagel、Dávid Komáromy、Wei Jiang、Christoph A. Schalley
DOI:10.1002/jms.3746
日期:2016.4
Thus, the release of molecular oxygen can serve as a reference reaction for the energy demand of other fragmentation reactions such as the dissociation of the crown/ammonium binding motifs. The photooxygenation induces curvature into the initially planar anthracene and thus significantly changes the geometry of the divalent, anthracene‐spacered wheel. This is reflected in ion‐mobility data. Coulomb repulsion