Hexabenzocoronene-Benzimidazole Hybrid Architectures and Faraday Rotation of the First Hexabenzocoronene-Phthalocyanine.

The synthesis and characterization of a first example of a Ni-phthalocyanine (Pc) hybrid molecule carrying four hexa-peri-hexabenzocoronene (HBC) substituents and of three HBC-benzimidazole derivatives is reported. These π-electron rich chromophores exhibit a high molar absorption coefficient with extended absorption up to 460 nm. Particularly, HBC-Pc absorbs throughout most of the UV-vis range with the Pc Q-band located at 672 nm. This enables its investigation as a Faraday rotator where it displayed a remarkable Verdet constant of -1.4 × 105 deg T-1m-1 at 700 nm assigned to Faraday A-term activity. Electrochemical measurements supported by DFT calculations elucidated the electronic structure of the molecules together with excited state molecular orbital analysis using TDDFT. Here, HBC-Pc showed a HOMO/LUMO gap considerably lower than the other HBC-based compounds due to the introduction of the Pc scaffold.