The influence on supramolecular aggregation patterns exerted by a new synthon, main group element (M) lone-pair⋯π(arene) interactions, is surveyed based on data mining studies of main group element crystal structures. Zero-, one-, and less commonly, two- and three-dimensional architectures are identified based on M(lp)⋯π(arene) interactions acting in isolation of other obvious intermolecular interactions, e.g. hydrogen bonding. Herein, an overview of the different aggregation patterns sustained by M(lp)⋯π(arene) interactions is given which, in the case of thallium(i), may occur in 13% of its crystal structures. General considerations of the formation propensities of M(lp)⋯π(arene) interactions, theoretical considerations and their role in macromolecular structures are also included.