Jump to main content
Jump to site search

Issue 10, 2006
Previous Article Next Article

Size-selected methyl lactate clusters: fragmentation and spectroscopic fingerprints of chiral recognition

Author affiliations

Abstract

A comprehensive experimental study of the OH stretching vibrations of size-selected clusters of enantiopure and racemic methyl lactate is presented. For the size selection, we measured angular dependent mass spectra and time-of-flight distributions at the different fragment masses. In this way the fragmentation of these clusters upon electron impact ionization is obtained. The largest fragment masses of the neutral (MLac)n clusters are the protonated (MLac)n−1H+ ions. The results of a pressure dependent study in an FTIR jet experiment are compared with completely size-selected experiments based on atomic beam deflection and depletion spectroscopy. The size assignments and spectra agree for dimers and trimers. Structures and spectral information for the trimer and the tetramer at density functional and MP2 level are provided. Selective self-aggregation and chiral recognition was observed for homochiral trimers. They exhibit a ring structure bound by OH⋯OH hydrogen bonds. A spectacular switch in the hydrogen bonding topology was observed for the tetramer. The homochiral enantiomer exhibits cooperative OH⋯OH bonding, while the heterochiral version shows isolated OH⋯O[double bond, length as m-dash]C bonding in a symmetric SRSR arrangement. The crucial ingredients for this identification are the size-selective IR spectra with their different shifts and line patterns which are reproduced by the calculations.

Graphical abstract: Size-selected methyl lactate clusters: fragmentation and spectroscopic fingerprints of chiral recognition

Back to tab navigation

Publication details

The article was received on 05 Oct 2005, accepted on 22 Dec 2005 and first published on 20 Jan 2006


Article type: Paper
DOI: 10.1039/B514117F
Citation: Phys. Chem. Chem. Phys., 2006,8, 1148-1158

  •   Request permissions

    Size-selected methyl lactate clusters: fragmentation and spectroscopic fingerprints of chiral recognition

    M. Fárník, M. Weimann, C. Steinbach, U. Buck, N. Borho, T. B. Adler and M. A. Suhm, Phys. Chem. Chem. Phys., 2006, 8, 1148
    DOI: 10.1039/B514117F

Search articles by author

Spotlight

Advertisements