Trifluoroethoxy-coating improves the axial ligand substitution of subphthalocyanine

A novel trifluoroethoxy (TFEO)-coated SubPc (1) and various axially functionalised derivatives thereof (2) have been efficiently synthesised. The advantage of the TFEO-coating on SubPcs compared to conventional fluorine-coated or uncoated molecules has been clearly demonstrated, as axial derivatisation has been realised in very good yields. Among various SubPcs synthesised, formyl-SubPc 2f has been further used as a building block for the synthesis of donor-acceptor SubPc-C₆₀ hybrid 8, while iodo-SubPc 2e has been used for the synthesis of trifluoroethoxy-coated SubPc-Pc dyads 9 and 10. All of these compounds are highly soluble in all common organic solvents, which greatly facilitates their purification and characterisation. The SubPcs 2a-c incorporating oligoethylene glycol moieties are attractive from a biological point of view, while SubPcs 8-10 may prove useful for studies of intramolecular electron- and energy-transfer processes.