Ab Initio Molecular Dynamics Simulations of Dye Molecules on Surfaces

Abstract

We have performed ab initio total energy calculations and molecular-dynamics simulations of dye molecules on NaCl(100) surfaces and in water. The flat dye molecule trimethine, [C 19 H 17 N 2 O 2 ] + , which forms sandwich-like structures, and the cyanine molecule monomethine, [C 21 H 23 N 2 ] + , which shows a typical stereochemical deformation due to two repulsive methyl groups, have been simulated. The molecular-dynamics simulations are able to reproduce the experimentally observed configuration of the charged molecules. The behavior of trimethine, [C 7 H 15 N 2 ] + , in water has also been simulated.