title: Cyclochiral resorcin[4]arenes as effective enantioselectors in the gas phase.
abstract: The effect of cyclochirality of rccc-2,8,14,20-tetra-n-decyl-4,10,16,22-tetra-O-methylresorcin[4]arene (C) on the enantiodiscrimination of a number of chiral bidentate and tridentate aromatic and aliphatic biomolecules (G) has been investigated by nano-electrospray ionization (nano-ESI)-Fourier transform ion cyclotron resonance mass spectrometry. The experimental approach is based on the formation of diastereomeric proton-bound [C·H·G](+) complexes by nano-ESI of solutions containing an equimolar amount of quasi-enantiomers (C) together with the chiral guest (G) and the subsequent measurement of the rate of the G substitution by the attack of several achiral and chiral amines. In general, the heterochiral complexes react faster than the homochiral ones, except when G is an aminoalcoholic neurotransmitter whose complexes, beyond that, exhibit the highest enantioselectivity. The kinetic results were further supported by both collision-induced dissociation experiments on some of the relevant [C(2) ·H·G](+) three-body species and Density functional theory (DFT) calculations performed on the most selective systems.
authors.affiliation: Department of Chemistry Bielefeld University, P.O. Box 100131, 33501, Bielefeld, Germany. caterina.fraschetti@uniroma1.it
authors.forename: Caterina
authors.initials: C
authors.lastname: Fraschetti
authors.forename: Matthias C
authors.initials: MC
authors.lastname: Letzel
authors.forename: Marlene
authors.initials: M
authors.lastname: Paletta
authors.forename: Jochen
authors.initials: J
authors.lastname: Mattay
authors.forename: Maurizio
authors.initials: M
authors.lastname: Speranza
authors.forename: Antonello
authors.initials: A
authors.lastname: Filippi
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Aschi
authors.forename: Alexander B
authors.initials: AB
authors.lastname: Rozhenko
mesh_terms: D047250:Calixarenes / Q000737:chemistry*; D005583:Fourier Analysis; D005740:Gases / Q000737:chemistry; D007700:Kinetics; D047028:Macrocyclic Compounds / Q000737:chemistry; D008958:Models, Molecular; D010649:Phenylalanine / Q000031:analogs & derivatives* / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013237:Stereoisomerism
chemical_list: D005740:Gases; D047028:Macrocyclic Compounds; C466160:resorcinarene; D047250:Calixarenes; D010649:Phenylalanine