Tri- and hexaferrocenyl-substituted subphthalocyanines in the quest for the optimum electron donor–acceptor distances

Three and six ferrocenyl subunits have been attached to the periphery of subphthalocyanines (SubPcs). Unlike axially coordinated ferrocenes, peripherally-bonded ferrocenes have an impact on the electronic features of SubPcs, which show a 44 to 70 nm red-shift of their Q-bands. The unusually deep and narrow ferrocenyl-SubPc is able to host C₆₀, giving rise to atypical SubPc•C₆₀ cocrystallates, through a combination of concave–convex and convex–convex π–π interactions.