ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
The reaction between ground state carbon atoms, C(3Pj), and acetylene, C2H2(1∑+g), was studied at an average collision energy of (8.4±0.3) kJ mol−1 using the crossed molecular beam technique. The product angular distribution and time-of-flight spectra of m/z=37, i.e., C3H, were recorded. Only m/z=37 was detected, but no signal from the thermodynamically accessible C3(1∑+g)+H2(1∑+g) channel. Forward-convolution fitting of the results yielded a center-of-mass angular flux-distribution forward scattered in respect to the carbon beam, whereas the translational energy flux distribution peaked at only (5.4±1.2) kJ mol−1, suggesting a simple C–H-bond-rupture to H+C3H. The reaction likely proceeds on the triplet surface with an entrance barrier to the C3H2–PES of 〈(8.4±0.3) kJ mol−1 via addition of the carbon atom to two bonding π-orbitals located both at C1 or at C1 and C2 of the acetylene molecule. The explicit identification of C3H product under single collision conditions strongly demands incorporation of atom-neutral reactions in reaction networks simulating chemistry in the interstellar medium, in interstellar shock waves, and in outflows of carbon stars. © 1995 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.469877
