This chapter focuses on the electrochemical properties of stable dipnictenes, and introduces d‐π electron systems including E=E π‐electron systems. It shows a summary of the redox potentials of diphosphene, distibene and dibismuthene obtained from cyclic voltammetry in CH₂Cl₂ (oxidation) and THF (reduction). The characteristic trend for the π‐electron systems involving heavier group 15 elements reported in the chapter is counterintuitive to the expectation that the energy level of the ‐π* orbital of an E=E double bond should be monotonously lowered upon descending group 15. It is feasible to expect that ‐π‐bonds between heavier group 15 elements should be more effective ‐π‐electron spacers relative to those consisting of second row elements. Detailed experimental investigations regarding ‐π‐bonds between heavier group 15 elements are described in the chapter and suggest that such ‐π‐bonds between heavier group 15 elements should work as effective ‐π‐spacers for transition metal moieties.