Abstract Intramolecular hydride transfer between 1, 4-dihydronicotinamide and nicotinamidium moieties connected by a polymethylene chain−(CH 2) n− is studied by the 1 H-spin saturation transfer technique. For n= 3 an effective molarity EM= 210 is found for the 4, 4′-hydride exchange which is not accompanied by the competing 4, 6′ and solvent exchange processes reported in related intermolecular reactions.