MOLECULAR SIMULATIONS OF INTERMOLECULAR HYDROGEN BOND ARRANGEMENTS IN [AU25(AIB)18]-1 CLUSTERS
Svetlana Gelpi-Dominguez1, Neranjan Perera2, José Gascón2.
1Universidad del Turabo, Gurabo, PR, 2University of Connecticut, Storrs, CT.
In this project, we develop a molecular mechanics (MM) force field to determine the amount of intermolecular hydrogen bond interactions found between the 18 oligopeptides ligands (L) protecting a 25-atom gold cluster. The oligopeptides consist of chains of 2-aminoisobutyric acid (Aib) units. Although, the [Au25(L)18]1- structure has not yet been experimentally solved, 1H NMR data gives clues as to how these ligands are structured around the Au cluster.This project used molecular simulations to carry out the following simulations: geometric optimization of a 1,393 atom structure of [Au25(L)18]1- , detection of the 18 intermolecular hydrogen bonds formed by the Aib ligands as suggested by the 1H NMR data, and determination of the integrity of the Aib’s 3-10 helical structure.