title: Negative ion formation in potassium-nitromethane collisions.
abstract: Ion-pair formation in gaseous nitromethane (CH(3)NO(2)) induced by electron transfer has been studied by investigating the products of collisions between fast potassium atoms and nitromethane molecules using a crossed molecular-beam technique. The negative ions formed in such collisions were analysed using time-of-flight mass spectroscopy. The six most dominant product anions are NO(2)(-), O(-), CH(3)NO(2)(-), OH(-), CH(2)NO(2)(-) and CNO(-). By using nitromethane-d(3) (CD(3)NO(2)), we found that previous mass 17 amu assignment to O(-) delayed fragment, is in the present experiment may be unambiguously assigned to OH(-). The formation of CH(2)NO(2)(-) may be explained in terms of dissociative electron attachment to highly vibrationally excited molecules.
authors: Laboratório de Colisões Atómicas e Moleculares, CEFITEC, Departamento de Física, FCT, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
authors: R
authors: R
authors: Antunes
authors: D
authors: D
authors: Almeida
authors: G
authors: G
authors: Martins
authors: N J
authors: NJ
authors: Mason
authors: G
authors: G
authors: Garcia
authors: M J P
authors: MJ
authors: Maneira
authors: Y
authors: Y
authors: Nunes
authors: P
authors: P
authors: Limão-Vieira