Molecule-based Mixed Conductor of Proton and Electron Composed of Neutral π-Planar Metal Complexes

Proton–electron-coupled functionalities of conductivity, magnetism, and optical properties in molecular crystals

“…1,10,[55][56][57] Over the last decade, attempts to extend the proton-electron coupling in the solution state to the solid state have been done to explore new and unique electronic functionalities. 20,[58][59][60][61][62][63][64][65][66] Nakanishi and Sato et al demonstrated proton transfer induced by spin-crossover behavior in a crystalline iron complex. 20 More recently, Henfling et al reported that a crystal of a closed-shell copper(I) pyrazinedithiolene complex with fully protonated ligands transitions to an open-shell copper(II) complex through dehydrogenation upon heating.…”

“…To date, pyrazine-or pyridine-substituted metal dithiolene complexes were found to exhibit multiple PCET in the solution state. [64][65][66][77][78][79][80][81][82] Herein, focus is on the usage of catechol-or alchoxybenzene-substituted metal dithiolene complexes to develop new proton-d/p-electron-coupled materials. 38,39,83,84 This chapter discusses our recent progress on proton-electron-coupled functionalities using metal dithiolene complexes.…”

Enhanced mixed proton and electron conductor at room temperature from chemically modified single-wall carbon nanotubes

“…On the other hand, some single-phase mixed proton-electron conductor materials also reported that can overcome the phase boundary issue, however, the observed performance should be further improved to use such materials in practical application. [11][12][13][14] Therefore, the development of efficient MPEC materials that can operate at room temperature is highly desirable for further advancement in the relevant research area.…”

An Approach to an Ideal Molecule-Based Mixed Conductor with Comparable Proton and Electron Conductivity

“…Very recently, we synthesized a dithiolate complex of nickel­(III) with a d 7 electron configuration formed with 1,4-naphthoquinone skeletons as Lewis acidic/basic sites, [Ni III (Hnqdt)­(nqdt)]·4.2H 2 O [nqdt 2– , 1,4-naphthoquinone-2,3-dithiolate; Ni–H (Figure a)] . It showed both proton and electron conduction; however, the room-temperature (RT) proton conductivity is 4 orders of magnitude lower than the RT electronic conductivity.…”