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

The helicoidal pi-conjugated structure from helicenes is able to feature cation-pi 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-pi 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-pi 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- pi complexes in infinitene is plausible, suggesting the expansion of its chemistry towards the formation of metal complexes in fused helicene species.

Automated summary

Recently, it has been discovered that infinitene, which consists of two fused [6]helicene structures with a central crossover section, can form cation-pi bonding with silver ions, leading to changes in its optical rotation properties. This suggests the potential for helicene compounds to form metal complexes.