Mass Spectrometry and Gas Phase Chemistry of Supramolecules

Hopping-Mediated Anion Transport through a Mannitol-Based Rosette Ion Channel

“…Electrospray ionization mass spectrometric (ESI-MS) studies were carried out to obtain direct evidence of anion recognition by mannitol 1 because the technique is suitable to deliver the direct experimental evidence of weak supramolecular interactions. , Samples were prepared in acetonitrile by mixing 1 with Me 4 NCl in 2:1 and 3:1 molar ratios and then electrosprayed under as mild as possible ionization conditions. When data were recorded from the 2:1 molar solution, formation of the 1 2 ·Cl – adduct was detected (Figure S10, SI).…”

Evidence for an intrinsic binding force between dodecaborate dianions and receptors with hydrophobic binding pockets

“…Thus, in an independent simultaneously performed study, we investigated inclusion complexes between different types of molecular hosts with hydrophobic binding pockets and dodecaborates in the gas phase, where possible solvent effects are excluded. 12 It should be noted that a doubly charged guest must be non-basic to ensure complex stability in the gas phase. Typical basic dianions would be immediately protonated by any acidic proton present in a host (such as HO-groups in cyclodextrins), leading to complex dissociation due to Coulomb repulsion.…”

“…Tetrathiafulvalene (TTF) containing compounds 2 and similar hosts containing two or more TTF units comprising an electron-rich binding pocket are known to bind electron deficient aromatic guests, such as tetracyanoquinodimethane, 17 nitroaromatic derivatives, 18,19 fullerenes, 18,20 or charged pyridinium derivatives. 12 Calix [4]arenebased 21 hosts 3 are complementary in size and their complexes with spherical hosts like fullerenes have been observed in crystal structures. Due to a large dipole moment of the azulene moiety, calix [4]azulenes 22 4 in the cone conformation have a strong permanent dipole moment with the positive side directed to the binding pocket, which was expected to stabilize a potential complex with [B 12 X 12 ] 2À .…”

Metallosupramolecular cages: from design principles and characterisation techniques to applications

“…For a general introduction to instrumentation and the study of supramolecules by mass spectrometry, the reader's attention is turned to reviews by Schalley. 65,66 For metallosupramolecular cages, mass spectrometry provides complementary information to NMR spectroscopy regarding the number of each building block within the structure and this can confirm the type of architecture proposed from the symmetry observed by NMR spectroscopy. There are a number of caveats, however, when comparing information obtained from mass spectrometry and NMR spectroscopy.…”