Million-Fold Electrical Conductivity Enhancement in Fe2(DEBDC) versus Mn2(DEBDC) (E = S, O)

Reaction of FeCl2 and H4DSBDC (2,5-disulfhydrylbenzene-1,4-dicarboxylic acid) leads to the formation of Fe-2(DSBDC), an analogue of M-2(DOBDC) (MOE-74, DOBDC4- = 2,5-dihydroxybenzene-1,4-dicarboxylate), The bulk electrical conductivity values of both Fe-2(DSBDC) and Fe-2(DOBDC) are similar to 6 orders of magnitude higher than those of the Mn2+ analogues, Mn-2(DEBDC) (E = O, S). Because the metals are of the same formal oxidation state, the increase in conductivity is attributed to the loosely bound Fe2+ beta-spin electron. These results provide important insight for the rational design of conductive metal-organic frameworks, highlighting in particular the advantages of iron for synthesizing Such materials.