title: Unravelling the dissociation pathways of acetic acid upon electron transfer in potassium collisions: experimental and theoretical studies.
abstract: Electron transfer in alkali-molecule collisions with gas phase acetic acid and its deuterated analogues resulting in OH-formation requires considerable internal rearrangement in the temporary negative ion. At a collision energy well above the threshold of negative ion formation, electron transfer from potassium to CH3COOH/CH3COOD and CD3COOH results not only in H transfer from CH3to COOH/COOD, but also in H release from COOH and subsequent rearrangement to eliminate OH-. These processes are also investigated by theoretical post-Hartree-Fock and DFT calculations. The combination of both studies reveals that the most favourable intermediate mechanism occurs via diol formation. Such intramolecular H transfer is reported here for the first time in the context of electron transfer induced dissociation experiments in alkali-molecule collisions. A comprehensive fragmentation study is presented and dissociation mechanisms are suggested.
authors.affiliation: Laboratório de Colisões Atómicas e Moleculares, CEFITEC Departamento de Física, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa Campus de Caparica, 2829-516 Caparica, Portugal. f.ferreiradasilva@fct.unl.ot.
authors.forename: G
authors.initials: G
authors.lastname: Meneses
authors.affiliation: Laboratório de Colisões Atómicas e Moleculares, CEFITEC Departamento de Física, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa Campus de Caparica, 2829-516 Caparica, Portugal. f.ferreiradasilva@fct.unl.ot.
authors.forename: C
authors.initials: C
authors.lastname: Widmann
authors.affiliation: Laboratório de Colisões Atómicas e Moleculares, CEFITEC Departamento de Física, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa Campus de Caparica, 2829-516 Caparica, Portugal. f.ferreiradasilva@fct.unl.ot.
authors.forename: T
authors.initials: T
authors.lastname: Cunha
authors.affiliation: Centro de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal. agmestres@fc.ul.pt.
authors.forename: A
authors.initials: A
authors.lastname: Gil
authors.affiliation: Laboratório de Colisões Atómicas e Moleculares, CEFITEC Departamento de Física, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa Campus de Caparica, 2829-516 Caparica, Portugal. f.ferreiradasilva@fct.unl.ot.
authors.forename: F
authors.initials: F
authors.lastname: Ferreira da Silva
authors.affiliation: Centro de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal. agmestres@fc.ul.pt.
authors.forename: M J
authors.initials: MJ
authors.lastname: Calhorda
authors.affiliation: Laboratório de Colisões Atómicas e Moleculares, CEFITEC Departamento de Física, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa Campus de Caparica, 2829-516 Caparica, Portugal. f.ferreiradasilva@fct.unl.ot.
authors.forename: P
authors.initials: P
authors.lastname: Limão-Vieira