Dynamical simulations of solutes in nanoconfined acetonitrile

CHED 975

Cassandra Norton, cnorton@emporia.edu, Chemistry Department, Emporia State University, 1200 Commercial St Box 4030, Emporia, KS 66801 and Ward H. Thompson, wthompson@ku.edu, Department of Chemistry, The University of Kansas, Lawrence, KS 66045.
There is great interest in developing solid, porous catalysts to carry out a wide variety of chemical transformations. However, little is known about the molecular-level properties of solutions confined in porous catalysts. One key issue in these systems is how readily reactants and products move to or away from active catalyst sites (typically embedded in the walls). A detailed understanding of chemical interactions within nanoscale pores would be useful in making more efficient catalysts. To this end, the locations and dynamics of small molecule solutes in nanoconfined acetonitrile inside hydroxyl-terminated silica pores are simulated using molecular dynamics. The effect of solute shape, polarity, and ability to hydrogen bond on dynamical and equilibrium properties are examined, comparing behavior in the bulk solvent to that in nanoconfined hydrophilic pores. Ten pores of the same nominal radius are used to probe the effects of heterogenity. The solutes considered in the simulations are water, methanol, formaldehyde, CO2 and CCl4; each have relatively unique reactions to confinement. The simulations reveal significant changes to the solute properties upon nanoconfinement and the origins are discussed.