Abstract
Noncovalent interactions of cucurbit[6]uril (CB[6]) with haloacetate and halide anions are investigated in the gas phase using electrospray ionization ion mobility mass spectrometry. Strong noncovalent interactions of monoiodoacetate, monobromoacetate, monochloroacetate, dichloroacetate, and trichloroacetate on the exterior surface of CB[6] are observed in the negative mode electrospray ionization mass spectra. The strong binding energy of the complex allows intramolecular SN2 reaction of haloacetate, which yields externally bound CB[6]-halide complex, by collisional activation. Utilizing ion mobility technique, structures of exteriorly bound CB[6] complexes of haloacetate and halide anions are confirmed. Theoretically determined low energy structures using density functional theory (DFT) further support results from ion mobility studies. The DFT calculation reveals that the binding energy and conformation of haloacetate on the CB[6] surface affect the efficiency of the intramolecular SN2 reaction of haloacetate, which correlate well with the experimental observation.
Original language | English |
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Pages (from-to) | 1786-1793 |
Number of pages | 8 |
Journal | Journal of the American Society for Mass Spectrometry |
Volume | 23 |
Issue number | 10 |
DOIs | |
Publication status | Published - 2012 Oct |
Externally published | Yes |
Keywords
- Anionic complex
- CB[6]
- Cucurbit[6]uril
- Electrospray ionization
- Halide
- Haloacetate
- Intramolecular S2 reaction
- Ion mobility spectrometry
ASJC Scopus subject areas
- Structural Biology
- Spectroscopy