Solvent Effects on the Energetics of the Phenol O−H Bond: Differential Solvation of Phenol and Phenoxy Radical in Benzene and Acetonitrile

• DOI: 10.1021/jp035912c
• Publication Date: 2003-10-23T04:44:09Z
• Authors: R. C. Guedes; Kaline Coutinho; B. J. Costa Cabral; Sylvio Canuto; C. F. Correia; R. M. Borges dos ...; J. A. Martinho Si...
• Keywords: 01 natural sciences; 0104 chemical sciences

Monte Carlo statistical mechanics simulations, density-functional theory calculations, time-resolved photoacoustic calorimetry, and isoperibol reaction-solution calorimetry experiments were carried out to investigate the solvation enthalpies solvent effects on energetics of phenol O−H bond in benzene acetonitrile. A good agreement between theoretical experimental results is obtained for The calculations also indicate that differences (PhOH) phenoxy radical (PhO•) both acetonitrile are significantly smaller than previous estimations based ECW model. used obtain dissociation For acetonitrile, 89.4 ± 1.2 90.5 1.7 kcal mol-1, respectively, with values (90.9 1.3 92.9 0.9 mol-1), by calorimetry. solute−solvent interaction energies differ less 2 mol-1. detailed analysis contributions differential enthalpy made terms hydrogen bonds interactions. Both PhOH PhO• induce a significant, although equivalent, reorganization enthalpy. Finally, convergence analyzed as function distance solute illustrates advantages limitations local models such microsolvation hydrogen-bond-only models.