Theoretical study on specific interaction between trimethylamine N-oxide and solvent molecules

Abstract

Trimethylamine N-oxide is well known as anosmolyte that is in marine organisms, for example, sharks.However,the mechanism is not completely unraveled even now. In previous studies, it was observed that TMAO had strong interaction with water molecules around it andgot a specific solvation structure. In this study, we treat dichloromethane and water as solvent molecules in order to find out whether or not there are the specific properties in solvation structure of TMAO in other solvent.We created some cluster structures with TMAO and solvent molecules, and optimized these cluster structure. The local minimum structure was confirmedby means of the normal mode analysis. It was found that TMAO interacted strongly with solvent molecules, which coordinated with an oxygen atom of TMAO when solvent was dichloromethane and water.Furthermore, the electron density onbond critical pointof the O…Hwas equal to that ofhydrogen bond inwater dimer.