Peripherally Hexasulfanylated Subporphyrins

Peripherally hexachlorinated meso‐triphenyl subporphyrin 4 was prepared by chlorination of meso‐triphenyl subporphyrin 1 with N‐chlorosuccinimide and was effectively transformed to hexasulfanylated subporphyrins 5 – 8 via nucleophilic aromatic substitution (S_NAr) reactions with the corresponding thiols under basic conditions. The structures of 5 – 8 have been all well characterized by single‐crystal X‐ray analysis. ¹H NMR studies indicated that the meso‐phenyl substituents undergo restricted rotation for 5 – 8 , while the β‐sulfanyl substituents are conformationally flexible in 5 , 6 , and 8 , and are strictly regulated to an anti‐conformation in 7 . Judging from the absorption spectra, the oxidation and reduction potentials, and the DFT calculations, the substituent effects decrease in the order of 5 > 6 > 7 > 8 . Subporphyrin 8 effectively captures C₆₀ in a 1:1 manner in D₈]toluene solution.