Coordination-induced reversible electrical conductivity variation in the MOF-74 analogue Fe₂(DSBDC)

Inner-sphere changes at the open Fe centers in Fe2(DSBDC) (DSBDC4- = 2,5-disulfidobenzene-1,4-dicarboxylate), as caused by coordination and release of solvent molecules, lead to reversible structural and electrical conductivity changes. Specifically, coordination of N,N-dimethylformamide (DMF) to the open Fe sites improves the room-temperature electrical conductivity by three orders of magnitude. Supported by additional density functional theory calculations, we attribute the electrical conductivity enhancement to partial electron transfer from Fe to DMF, which generates hole carriers and improves the charge carrier density in Fe2(DSBDC).