Infrared photodissociation spectroscopy of protonated neurotransmitters in the gas phase

J.P. Simons (1)

1 PTCL

Protonated neurotransmitters have been produced in the gas phase via a novel photochemical scheme: complexes of the species of interest, 1-phenylethylamine, 2- amino-1-phenylethanol and the diastereo-isomers, ephedrine and pseudoephedrine, with a suitable proton donor, phenol (or indole), are produced in a supersonic expansion and ionised by resonant two photon ionisation of the donor. Efficient proton transfer generates the protonated neurotransmitters, complexed to a phenoxy radical. Absorption of infrared radiation, and subsequent evaporation of the phenoxy tag, coupled with time of flight mass spectrometry, provides vibrational spectra of the protonated (and also hydrated) complexes for comparison with the results of quantum chemical computation. Comparison with the conformational structures of the neutral neurotransmitters (established previously) reveals the effect of protonation on their structure. The photochemical proton transfer strategy allows spectra to be recorded from individual laser shots and their quality compares favourably with that obtained using electro-spray or matrix assisted laser desorption ion sources.

Mots clés: Physical Sciences

J.P. Simons. Infrared photodissociation spectroscopy of protonated neurotransmitters in the gas phase. Molecular Physics, 2007, 104 (20-21), pp.3317-3328. ⟨10.1080/00268970601110340⟩. ⟨hal-00513063⟩