Chiral self-assemblies of amino-acid molecules: D - and L -methionineon Au(111) surface

• Published in: Applied physics letters 2010-12, Vol.97 (22), p.223112-223112-3
• Main Authors: Naitabdi, A., Humblot, V.
• Format: Article
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.3524229

Spontaneous self-assembly into chiral well-ordered two-dimensional molecular film at room temperature has been evidenced using the scanning tunneling microscopy for the growth of two enantiomerically pure L - and D -methionine on Au(111) surface. From the x-ray photoelectron spectroscopy measurements, the growth of methionine occurs through the formation of zwitterionic species. Our results demonstrate that this self-assembly mechanism is crucially driven by the interchain interactions via zwitterionic hydrogen bonding between neighboring negatively charged carboxylate groups and positively charged amino groups. Moreover, the molecular pair formation is incidental and results from the optimization of the interchain interactions, at least two chains are required for stability.