Abstract

An organic–inorganic cation–anion manganese(II) tetraiodide compound with P,P′-diprotonated bis(2-diphenylphosphinophenyl)ether, [H₂DPEphos][MnI₄], has been synthesized and investigated. The compound has a few possible pathways for proton transfers which play an important role in the observed luminescence. The proton transfers result in the appearance of two-band luminescence and facilitate the charge transfer from organic cation to the manganese(II) ion. These bands correspond to the d–d transitions of manganese(II) and are coupled through {[H₂DPEphos]}-{[MnI₄]} vibrations. This leads to the averaging of the luminescence lifetimes for both band and the unexpected short observed luminescence lifetime. The reason for the two-band luminescence was additionally considered using the DFT calculations.