Kinetic investigation of reactions of atomic carbon, C[2p2(3PJ)], with simple nitrogen-containing molecules and aromatic heterocyclic compounds

Abstract

The reactions of atomic carbon in its electronic ground state, C[2p2(3PJ)], with some simple nitrogen-containing molecules and aromatic heterocyclic compounds have been investigated by time-resolved atomic resonance absorption spectroscopy in the vacuum ultra-violet following the generation of C(23PJ) by the pulsed photolysis of C3O2. Decay profiles for atomic carbon were derived from resonance absorption measurements at ? = 166 nm (33PJ?23PJ) using repetitive pulsing techniques coupled with signal averaging. Absolute rate data for the collisional removal of C(23PJ) by these gases were obtained as follows: kR (cm3 molecule?1 s?1, 300 K): NH3 < 1.1 ? 10?1, 1-propanamine < 8.2 ? 10?12, 2-methylpyridine = 5.3 � 0.6 ? 10?10, 4-methylpyridine = 5.5 � 0.2 ? 10?10, 1-methylpyrrole = 2.3 � 0.5 ? 10?10, thiazole = 2.9 � 0.2 ? 10?10, oxazole = 2.4 � 0.2 ? 10?10 and isoxazole = 2.2 � 0.3 ? 10?10. The rate data were compared, where possible, with absolute rate data for analogous collision targets reported hitherto and considered within the context of the role of atomic carbon in the interstellar medium.