We establish a structure-property relation for the system having a cyclooctatetraene (COT) ring fused with four five-membered heterocyclic rings. The two five-membered heterocycles selected are furan and selenophene and their fused structure with COT is known as cyclooctatetrafuran (COF) and cyclooctatetraselenophene (COSe), respectively. We found 15 geometrical isomers of each COF and COSe and their structural stability and optoelectronic properties have been evaluated by quantum chemical simulations. The density functional theory (DFT) and time-dependent DFT simulations were employed for a systematic review of all isomers. Electronic excitations, hole reorganization energies, electron reorganization energies, ionization potentials, and electron affinities, of all the isomers, were reported. Based on our comparative study, it is shown that one of the isomers is suggested as a better charge transport material.

By using molecular dynamics simulation, we investigate the wettability of a surface texturized with a periodic array of hierarchical pillars. By varying the height and spacing of the minor pillars on top of major pillars, we investigate the wetting transition from the Cassie–Baxter (CB) to Wenzel (WZ) states. We uncover the molecular structures and free energies of the transition and meta-stable states existing between the CB and WZ states. The relatively tall and dense minor pillars greatly enhance the hydrophobicity of a pillared surface, in that, the CB-to-WZ transition requires an increased activation energy and the contact angle of a water droplet on such a surface is significantly larger.