Gas-phase acidities and O-H bond dissociation enthalpies of phenol, 3-methylphenol, 2,4,6-trimethylphenol, and ethanoic acid.
Energy-resolved, competitive threshold collision-induced dissociation (TCID) methods are used to measure the gas-phase acidities of phenol, 3-methylphenol, 2,4,6-trimethylphenol, and ethanoic acid relative to hydrogen cyanide, hydrogen sulfide, and the hydroperoxyl radical using guided ion beam tandem mass spectrometry. The gas-phase acidities of Delta(acid)H298(C6H5OH) = 1456 +/- 4 kJ/mol, Delta(acid)H298(3-CH3C6H4OH) = 1457 +/- 5 kJ/mol, Delta(acid)H298(2,4,6-(CH3)3C6H2OH) = 1456 +/- 4 kJ/mol, and Delta(acid)H298(CH3COOH) = 1457 +/- 6 kJ/mol are determined. The O-H bond dissociation enthalpy of D298(C6H5O-H) = 361 +/- 4 kJ/mol is derived using the previously published experimental electron affinity for C6H5O, and thermochemical values for the other species are reported. A comparison of the new TCID values with both experimental and theoretical values from the literature is presented.
Angel
Laurence A
LA
Department of Chemistry and Chemical Physics Program, University of Nevada, Reno, 1664 North Virginia Street, Reno, Nevada 89557, USA.
Ervin
Kent M
KM
D019342:Acetic Acid / Q000737:chemistry*; D003408:Cresols / Q000737:chemistry*; D005740:Gases / Q000737:chemistry; D006878:Hydroxides / Q000737:chemistry*; D008956:Models, Chemical; D019800:Phenol / Q000737:chemistry*; D011789:Quantum Theory; D013816:Thermodynamics
D003408:Cresols; D005740:Gases; D006878:Hydroxides; D019800:Phenol; C505148:2,4,6-trimethylphenol; C042041:3-cresol; D019342:Acetic Acid