Bis-thioether-Substituted Perylene Diimides: Structural, Electrochemical, and Spectroelectrochemical Properties

The synthesis and separation of the 1,6- and 1,7- isomers of N,N'-bis(alkyl)diadamantylthio-3,4,9,10-perylenetetracarboxylic acid diimide are reported. Investigations of the structural, electrochemical, spectroscopic, and spectroelectrochemical properties of the isomers reveal a sequence of electrochemically and chemically reversible reduction processes for both isomers. Three X-ray crystal structures are reported including a pair of 1,6- and 1,7-isomers demonstrating the twist of the perylene core in the solid state. Our studies thoroughly characterize the mono- and direduced states of the two isomers allowing unequivocal characterization of the reduced species by UV-vis and IR spectroscopic measurements. EPR studies also allow direct identification of the monoreduced PTCDI species and spectroscopic measurements confirm the delocalization of electronic density around the carbonyl moieties of the reduced species.