Aggregation of coronene: The effect of carboxyl and amine functional groups

10 pags., 9 figs., 4 tabs.The aggregation of coronene is relevant to understand the formation of carbon nanomaterials, including graphene quantum dots (GQDs) that show exceptional photophysical properties. This article evaluates the influence of carboxyl and amine substituting groups on the aggregation of coronene by performing a global optimization study based on a new potential energy surface. The structures of clusters with substituted coronene are similar to those formed by un-substituted monomers, that is, stacked (non-stacked) motifs are favoured for small-size (large-size) clusters. Nonetheless, the presence of carboxyl and amine groups leads to an increase of the number of local minima of comparable energy. The clusters with substituted monomers have also shown to enhance the attractive component interaction, which can be attributed to weak induction and charge transfer effects and to stronger electrostatic contributions. Moreover, the calculated height of magic-number structures of the clusters in this work is compatible with the morphology of the GQDs reported in the literature. This journal isJ. M. C. M. acknowledges the support from the Coimbra Chemistry Centre (CQC), which is financed by the Portuguese ‘‘Fundaçao para a Ciencia e a Tecnologia’’ (FCT) through the programmes UIDB/ 00313/2020 and COMPETE. We are also grateful for the provision of computational time in the supercomputer resources hosted at Laboratorio de Computaça˜o Avançada, Universidade de Coimbra. M. B. acknowledges financial support by the Spanish ‘‘Ministerio de Ciencia e Innovacion’’ for the FIS2017-84391-C2-2-P grant as well as the allocation of computing time by CESGA supercomputing center (Spain). E. M., J. M. G. M. and C. F. O. C. thank FCT for funding: PTDC/NAN-MAT/29317/2017, UIDB/00100/2020 and PD/ BD/127805/2016