Berlin 2001 – scientific programme
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MO: Molekülphysik
MO 12: Posters Friday: Spectroscopy
MO 12.10: Poster
Friday, April 6, 2001, 12:30–15:00, AT3
Study of chirality and intermolecular forces in supersonic beam using Resonant Photoionization — •Anna Giardini1,2, Susanna Piccirillo3, Debora Scuderi1,4, Mauro Satta1, Tonia Di Palma2, Maurizio Speranza4, and Alessandra Paladini1 — 1Chem.Dept.University of Rome "La Sapienza", Pl. A. Moro 5, I-00185 Roma, Italy — 2CNR-IMS, (Pz), Italy — 3STC Dept.University of Rome "Tor Vergata" Roma, Italy — 4CTF University of Rome "La Sapienza" Roma, Italy
Many biochemical reactions display a pronounced enantioselectivity due to different interactions between chiral molecules. In the condensed phase due to the unavoidable presence of the solvent interpretation of chiral discrimination is not simple. In gas phase chiral recognition is based on different chemical physical properties of the diastereomeric complexes formed by a chiral molecule and chiral solvents [1]. Mass-resolved resonant two-photon-ionization (R2PI) coupled with time of flight (TOF) mass spectrometry allows to study weakly bound aggregates formed in supersonic beam at temperature T<10 K. One and two-color, mass selected R2PI spectra of the S1<-S0 transitions in the bare cromophore and its complexes have been recorded. Diastereomeric complexes spectra are characterized by significant shits of their band origin relative to that of bare cromophore, whose extent and direction depend upon different short-range interactions in the ground and excited states of complexes. The data have been compared with DFT calculations. [1] A. Latini et al., Chem. Eur. J. 6 (2000) 1042-9.