Abstract

A combined methodology of semiempirical density functional (DFT) and Hartree−Fock (HF) theories is used to analyze the solution-phase proton-transfer (PT) process in the H2O···HX (X = F, Cl, and OH) model systems. Gas-phase PT, hydrogen bonding, ion-pairing, dissociation, and solvent effect are considered as the contributing factors to the solution PT reaction. The H-bonded and ion-pair structures are determined from the proton-transfer potential (PTP) profiles and full geometry optimization, using the Amsterdam density functional (ADF) code. These structures are then used as input to the semiempirical SCRF/CNDO method that incorporates solvent effects. The semiempirical SCRF gas-phase results qualitatively reproduce the experimental trend for the gas-phase proton affinities (PA) (OH- > F- > Cl-). The solution-phase results correctly explain the strong acid character of HCl (pKa < 0) and the weak dissociation of HF (pKa > 0) in water.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.