Rotationally resolved reaction product imaging using crossed molecular beams

The hydrogen abstraction reactions of atomic chlorine with ethane and n-butane are studied in a skimmerless crossed molecular beam experiment by imaging of state-selected products. The differential cross section for HCl(v = 0, J = 1–5) product is directly determined from the product velocity map image. The state selection of products is achieved using (2 + 1) resonance enhanced multiphoton ionization, a method generally not used in crossed-molecular beam experiments due to sensitivity problems. This technique opens the way for a plethora of polyatomic reactions (involving more than three atoms) to be studied with scattering angle and rotational resolution.