Tuning Electronic Relaxation of Nanorings Through Their Interlocking

Abstract

Electronic and vibrational relaxation processes can be optimized and tuned by introducing alternative pathways that channelexcess energy more efficiently. An ensemble of interacting molecular systems can help overcome the bottlenecks caused by largeenergy gaps between intermediate excited states involved in the relaxation process. By employing this strategy, catenanes com-posed of mechanically interlocked carbon nanostructures show great promise as new materials for achieving higher efficienciesin electronic devices. Herein, we perform nonadiabatic excited state molecular dynamics on different all-­benzene catenanes. Weobserve that catenanes experience faster relaxations than individual units. Coupled catenanes present overlapping energy mani-folds that include several electronic excited states spatially localized on the different moieties, increasing the density of states thatultimately improve the efficiency in the energy relaxation. This result suggests the use of catenanes as a viable strategy for tuningthe internal conversion rates in a quest for their utilization for new optoelectronic applications.