Abstract by Jamir Shrestha
Chemistry and Biochemistry
Determining topologies of alkylammonium complexes of Cucurbituril using multiCRAFTI techniques in an FTICR mass spectrometer.
Hollow, pumpkin-shaped cucurbituril (CB) is known to form complexes with cationic species like alkylammonium ions. Singly charged 1:1 and doubly charged 1:2 complexes with alkylmonoammonium ions are detected in the gas phase using FTICR. Several isomeric forms are possible: the alkyl chains may bind inside or outside the cage, or with a part of the alkyl chain protruding. One way to address the question is through collision cross section measurements. Externally-bound complexes have larger cross sections than complexes with the alkyl chain inside the CB cavity. We have applied the cross sectional areas by Fourier transform ion cyclotron resonance (“CRAFTI”) technique to address this question, using simultaneous measurements of 2 complexes (“multiCRAFTI”) to measure cross sections against an internal standard.