A comparative analysis of symmetric diketopyrrolopyrrole‐cored small conjugated molecules with aromatic flanks: From geometry to charge transport.

Diketopyrrolopyrrole (DPP) derivatives are promising compounds for application in organic electronics. Here, we investigate several symmetrical N‐unsubstituted and N‐methyl substituted DPPs which differ in the heteroatom in the aromatic flanks. The conformational, electronic, and optical properties are characterized for single molecules in vacuum or a solvent. The intermolecular interactions are evaluated for interacting dimers. Here, a number of stacking geometries is tested, and dimers with mutual orientation of the molecules corresponding to the minimal binding energies are determined. The predicted charge carrier mobilities for stacks having minimal binding energies corroborate experimentally measured values. We conclude that DFT prediction of such stacks is a promising and computationally inexpensive approach to a rough estimation of transport properties. Additionally, the super‐cell of the experimentally resolved crystal structure is used to study the dynamics and to compute the charge transport along the hopping pathways. We discuss obtained high mobilities and relate them to the symmetry of DPP core. © 2018 Wiley Periodicals, Inc. Small symmetric conjugated molecules with diketopyrrolopyrrole core decorated by thiophene or furan aromatic rings are modeled with atomistic details in DFT/MD simulations. The calculation of stacks of two identical molecules characterizing by the lowest binding energy is considered as a promising, computationally inexpensive approach to a rough estimation of the electronic coupling. The molecular dynamics simulation of DPP crystal at room temperature provides the carrier mobilities in all possible hopping pathways. [ABSTRACT FROM AUTHOR]