Computational Studies of Nanographene Systems: Extended Discotics, Covalently Linked "Supermolecules," and Functionalized Supramolecular Assemblies

Finite nanographene molecules in the form of discotic mesogens constitute a promising family of materials for a plethora of applications, primarily focused on organic electronics. Flexible side chains around the periphery of such molecules impart solubility and prompt self-organization mechanisms inherent to soft matter systems. In this work, both quantum chemical and classical simulation method- ologies are employed to examine electronic, charge transport, structural, and dynamical properties of discotic materials at multiple scales, ranging from single-molecule representations to bulk supramolecular assemblies. In addition to planar molecules of variable core extent, a series of covalently linked "supermolecules" are considered, exhibiting diverse electronic properties and low charge reorganization energies, and unique self-organization capabilities in the form of triple helix molecular wires. A hybrid Monte Carlo methodology is proposed and utilized for the creation of plausible initial configurations for atomistic simulations in the bulk. Novel chiral supramolecular assemblies based on discotic "supermolecules" in the form of periodic molecular crystals and interfacial systems are proposed and examined with potential charge transport applications, and estimations of their charge transfer capabilities are carried out at the level of frontier molecular orbital interactions.