Chiral self-assemblies of amino-acid molecules: D- and L-methionine on Au„111… surface

摘要

Spontaneous self-assembly into chiral well-ordered two-dimensional molecular film at roomntemperature has been evidenced using the scanning tunneling microscopy for the growth of twonenantiomerically pure L- and D-methionine on Auu0002111u0003 surface. From the x-ray photoelectronnspectroscopy measurements, the growth of methionine occurs through the formation of zwitterionicnspecies. Our results demonstrate that this self-assembly mechanism is crucially driven by theninterchain interactions via zwitterionic hydrogen bonding between neighboring negatively chargedncarboxylate groups and positively charged amino groups. Moreover, the molecular pair formation isnincidental and results from the optimization of the interchain interactions, at least two chains arenrequired for stability. © 2010 American Institute of Physics. u0004doi:10.1063/1.3524229