On the Cation-π capabilities of infinitene (∞). Evaluation of bonding and circular dichroism properties for Infinitene-Ag(I)n (n = 1–4) complexes from relativistic DFT calculations

Abstract

The helicoidal π-conjugated structure from helicenes is able to feature cation-π bonding towards Ag(I) atoms, resulting in the variation of their inherent high optical rotation values. Recently, the characterization of infinitene ([12]infinitene) as two fused [6]helicene structures with a central crossover section suggests the extension of such coordination characteristics to large and more complex structural landscapes. Herein, we evaluated the possible cation-π features of infinitene towards one to four silver cations from density functional calculations and their role in the optical rotation of the infinity-shaped backbone. The nature of the cation-π interaction for infinitene, shows a favorable formation of single and multiple Ag(I) aggregation, with a slight distortion of the structural backbone. Hence, the formation of cation- π complexes in infinitene is plausible, suggesting the expansion of its chemistry towards the formation of metal complexes in fused helicene species.