Journal article
Use of diastereomeric interactions to probe the inplane attachment of water-soluble molecules to the polar head groups of Langmuir films of Cu-alpha-amino acid complexes
Journal of Physical Chemistry B, Vol.103(33), pp.6891-6899
Aug/1999
Abstract
To provide more direct information on the role played by "tailor-made" auxiliary molecules in the early stages of crystal nucleation, the interplay between dusters of polar headgroups of monolayers of the copper complexes S-Cu-S' and S-Cu-R' and water-soluble copper complexes S'-Cu-S' and R'-Cu-R' were investigated [where S represents enantiomerically pure (S)-palmitoyl-N(epsilon)-lysine, and S' and R' represent chiral resolved (S) and (R) forms of alanine, serine, or valine]. The different monolayers were formed by spreading the amphiphilic (R) or (S) alpha-amino acid on an aqueous solution of copper acetate followed by injection of the water-soluble (S') or (R') alpha-amino acid into the subphase. The surface pressure-molecular area isotherms of the Langmuir monolayers of the two type of complexes (S-Cu-S' and S-Cu-R') are different, the former being substantially more expanded. The polar headgroups of the S-Cu-S' and of the S-Cu-R' monolayers transferred onto a solid support assume a hans and cis configuration, respectively, according to comparative X-ray photoelectron spectroscopy (XPS) studies with appropriate cis and trans three-dimensional (3-D) alpha-amino acid Cu complexes. A grazing incidence X-ray diffraction (GIXD) analysis demonstrated that the S-Cu-S' and S-Cu-R' monolayers have different 2-D crystal structures, in keeping with the XPS results. A model is presented suggesting that the water-soluble S'-Cu-S' copper complexes are enantioselectively bound to the periphery of the domains of the cis S-Cu-S' monolayers, but not to the domains of the trans S-Cu-R' monolayers. By symmetry, the same principal holds for the monolayers and water soluble copper complexes of alpha-amino acids of the opposite handedness.
Details
- Title
- Use of diastereomeric interactions to probe the inplane attachment of water-soluble molecules to the polar head groups of Langmuir films of Cu-alpha-amino acid complexes
- Creators
- M Berfeld (null) - The Weizmann Institute of ScienceI Kuzmenko (null) - The Weizmann Institute of ScienceIsabelle Weissbuch (null) - The Weizmann Institute of ScienceHagai Cohen (null) - 972WIS_INST___100PB Howes (null) - Technical University of DenmarkK Kjaer (null) - Technical University of DenmarkJ Als-Nielsen (null) - University of CopenhagenLeslie Leiserowitz (null) - The Weizmann Institute of ScienceMeir Lahav (null) - The Weizmann Institute of Science
- Resource Type
- Journal article
- Publication Details
- Journal of Physical Chemistry B, Vol.103(33), pp.6891-6899; Aug/1999
- Number of pages
- 9
- Language
- English
- DOI
- https://doi.org/10.1021/jp990561g
- Grant note
- We thank Dr. S. Mathlis for the SFM and R. Buller for some of the surface pressure vs molecular area isotherm measurements. We acknowledge financial support from the German Israeli Foundation, GIF, and the Dansyne program of the Danish Foundation for Natural Sciences and E.U.'s TMR program, and we thank HASYLAB, Desy, Hamburg, for synchrotron beam time.
- Record Identifier
- 993267133403596
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