{Mo4}-directed structural evolution of highly reduced molybdenum red clusters for efficient proton conduction

A series of highly reduced Mo red clusters {Mo₂₈} (1), {Mo₃₀} (2), and {Mo₄₀} (3) are synthesized from the rational assembly of planar {MoV4} building blocks and employed for proton conduction. 3 exhibits the best conductivity of 7.56 × 10^-3 S cm^-1 under optimal conditions due to the most efficient hydrogen-bonding network.