Gas-phase clustering reactions of NO 2−, C 2H 3NO 2−, C 2H 4NO 2−, C 2H 5NO 2− and C 2H 5NO 4− with C 2H 5NO 2

Abstract

The gas-phase negative ion–molecule reactions of C 2H 5NO 2 have been investigated by pulsed electron-beam high-pressure mass spectrometer. Association of C 2H 5NO 2 with O 2 − leading to C 2H 5NO 4 − and its clusters was observed, increasing in relative importance with decreasing temperature. The clustering reactions A −(C 2H 5NO 2) n−1 +C 2H 5NO 2⇄A −(C 2H 5NO 2) n for A=NO 2, C 2H 3NO 2, C 2H 4NO 2, C 2H 5NO 2 and C 2H 5NO 4 were studied, and the thermochemical data, Δ H° n−1, n and Δ S° n−1, n , for these reactions were determined. The decay rates found for CH 3NO 2 −(CH 3NO 2) n and C 2H 5NO 2 −(C 2H 5NO 2) n are significantly higher than those of other clusters studied. We consider the influence of the dipole-bound states of the core anions, CH 3NO 2 − and C 2H 5NO 2 −, on the transport dynamics of their clusters.