Intramolecular Hydrogen Bonding Effect on the Electron-Transfer Thermodynamics of a Series of o-Nitrobenzyl Alcohol Derivatives

Abstract

From thermoelectrochemical experiments and electronic structure calculations of a series of nitrobenzyl alcohol derivatives, the effect of intramolecular hydrogen bonding (IHB) on the electron transfer thermodynamics is discussed on a molecular basis. A linear correlation between formal reduction potential (E 1/2 ) values and temperature was obtained for the temperature range from 300 to 350 K. Estimated electron transfer entropy values (ΔS)�determined from this dependence�and the enthalpy (ΔΔH) changes relative to o-nitrobenzyl alcohol confirmed that the effect of the formation of IHB proved to be decisive in the chargetransfer thermodynamics. The possibility of intermolecular hydrogen bonding is further discussed upon comparing thermodynamic data among three different solvents.