Ab initio Modeling of amide-stabilized, oligo(ethylene glycol)-terminated self-assemblies: In-SAM molecular geometry, orientation, and hydrogen bonding

作者：Malysheva Lyuba; Onipko Alexander; Liedberg Bo^*

来源：Journal of Physical Chemistry A, 2008, 112(8): 1683-1687.

DOI：10.1021/jp711604h

Under the constraint that sulfur atoms form a hexagonal (root 3 x root 3)R30 degrees overlayer on the (111) gold surface, the optimized geometry of periodic arrays of HS(CH2)(3)CONH-(CH2CH2O)(3)H molecules has been found ab initio, by exploiting the BP86 exchange-correlation functional with 6-31G and "general" basis sets. The obtained data suggests that several prominent features of in-SAM molecular geometry and orientation stand out from conclusions based on single-molecule modeling. In particular, changing of amide-related dihedrals is shown to dominate in adjustment of molecular constituents to the assembly environment and to result in a substantial shortening of the hydrogen bond distance between nearest-neighbor amides. First demonstrated here, the full account to the intermolecular interaction within periodic arrays of amide-bridged, oligo(ethylene glycol)-terminated alkanethiolates forms a new platform for arguable modeling of SAM apparent properties.

• 出版日期2008-2-28