Self-Assembly of Nanocubic Molecular Capsules via Solvent-Guided Formation of Rectangular Blocks

We investigate the mechanism underlying the self-assembly of gear-shaped amphiphilic molecules into a highly ordered nanocubic capsule ("nanocube") in aqueous methanol. Simulation results show that the solvent molecules play a significant role in the assembly process by directing the primitive intermediates to orthogonal/rectangular shapes, thus creating appropriate building blocks for cubic assembly while avoiding off-pathway stacked aggregates. Free-energy analyses reveal that the interplay of the direct intermonomer interaction and the solvent-mediated repulsion between large aromatic cores (via preferential solvation of methanol on hydrophobic surfaces) leads to the strong trend for perpendicular binding of monomers and hence the solvent-guided formation of rectangular blocks. Furthermore, we report the self-assembly simulation of the nanocube using replica exchange with solute tempering and demonstrate that the simulation can predict a highly ordered nanocapsule structure, assembly intermediates, and encapsulated molecules, which helps promote computer-aided design of functional molecular self-assemblies in explicit solvent.

Probing the interaction between solid benzene and water using vacuum ultraviolet and infrared spectroscopy

Benzene exhibits strong concentration dependent energy shifts of electronic states in solid phase mixtures with water ice.

Electrons, excitons and hydrogen bonding: electron-promoted desorption from molecular ice surfaces

Desorption of benzene from methanol and diethyl ether ices during irradiation with 250 eV electrons is reported and compared with our previous work on benzene/water ices to highlight the role of hydrogen bonding in excitation transport.