Photooxygenation and Gas-Phase Reactivity of Multiply Threaded Pseudorotaxanes

Nowosinski, K.; Warnke, S.; Pagel, K.; Komáromy, D.; Jiang, W.*; Schalley, C. A.*— 2015

The solution-phase photooxygenation of multiply threaded crown/ammonium pseudorotaxanes containing anthracene spacers is monitored by electrospray ionization Fourier-transform ion-cyclotron-resonance (ESI-FTICR) mass spectrometry. The oxygenated pseudorotaxanes are mass-selected and fragmented by infrared multiphoton dissociation (IRMPD) and/or collision-induced dissociation (CID) experiments and and their behavior compared to that of the non-oxygenated precursors. [4+2]Cycloreversion reactions lead to the loss of O2, when no other reaction channel with competitive energy demand is available. 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 in multiply charged pseudorotaxanes assists the oxygen loss as the re-planarization of the anthracene increases the distance between the two charges.

TitlePhotooxygenation and Gas-Phase Reactivity of Multiply Threaded Pseudorotaxanes
AuthorNowosinski, K.; Warnke, S.; Pagel, K.; Komáromy, D.; Jiang, W.*; Schalley, C. A.*
Date2015
Identifier10.1002/jms.3746
Source(s)
CitationJ. Mass Spectrom. 2016, 51, 269-281
TypeText