The Intramolecular Electronic Interaction Regulated by Five-membered Heterocycle Spacer

Abstract

The spacer in diferrocenyl derivatives has significant effects on intramolecular electronic interaction properties. In this work, nine diferrocenyl five-membered heterocyclic molecules are synthesized as models to investigate the effect of intramolecular electron-transfer properties systematically, including 2,5-diferrocenyl-1-phenyl-pyrrole (1), 2,5-diferrocenylfuran (2), 2,5-diferrocenylthiophene (3), 2,5-diferrocenyl-1H-imidazole (4), 2,5-diferrocenyloxazole (5), 2,5-diferrocenylthiazole (6), 2,5-diferrocenyl-1,3,4-triazole (7), 2,5-diferrocenyl-1,3,4-oxadiazole (8) and 2,5-diferrocenyl-1,3,4-thiadiazole (9). The molecules were prepared in cyclization reaction and characterized by Elemental analysis, FT-IR, MS and NMR. Moreover, the molecular structures of 2,5-diferrocenylthiazole and 2,5-diferrocenyl-1,3,4-oxadiazole were determined by the single crystal X-ray diffraction. The intramolecular electronic interactions were investigated through cyclic voltammetry in combination with density functional theory (DFT) calculations. The results revealed that the electronic interaction decreased with the increase of heteroatoms in central heterocycle spacer, and the electron-transfer property could be regulated by regulate central heterocycle spacer species.