Spectroscopic discrimination of diastereomeric complexes involving an axially chiral receptor
The infrared multiphoton dissociation (IRMPD) spectra of electrospray ionization (ESI)-formed proton-bound complexes between the axially chiral multifunctional macrocycle MaR and d- and l-phenylalanine (PD and PL ) or d- and l-3,4-dihydroxyphenylalanine (DD and DL ) are recorded in the ?˜ =2800-3700?cm-1 region. Whereas the diastereomeric [MaR ?H?PD ]+ and [MaR ?H?PL ]+ complexes do not show any significant spectral differences, the spectrum of [MaR ?H?DD ]+ clearly diverges from that of its [MaR ?H?DL ]+ diastereomer.