A Mn–K heterometallic MOF, [KMn(I3)(L)2(H2O)]n (HL = D-saccharic acid 1,4-lactone) (1), has been synthesized from a benzene solution. X-Ray single crystal structural analysis shows that MOF 1 is the first MOF based on the L− ligand and belongs to the chiral space group P1. MOF 1 features an unusual (3,7)-connected tcj-3,7-Amm2 topological network with the Mn–K dimetal units interlinked by the L− ligands and water molecules. The Mn(II) pentagonal bipyramidal polyhedron and K(I) monocapped square antiprism polyhedron share a triangular plane and generate the final 3D chiral framework with rectangular channels occupied by I3− ions. Cyclic voltammetry studies have been conducted in the solid state.