Negative ion formation in potassium-nitromethane collisions.
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.
Antunes
R
R
Laboratório de Colisões Atómicas e Moleculares, CEFITEC, Departamento de Física, FCT, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
Almeida
D
D
Martins
G
G
Mason
N J
NJ
Garcia
G
G
Maneira
M J P
MJ
Nunes
Y
Y
Limão-Vieira
P
P