Cover Picture: Journal of the Chinese Chemical Society 5/2012

Oriented molecular beams provide us direct microscopic information on reaction dynamics in bimolecular as well as photodissociation systems. The oriented & crossed beam experiment of OH + HBr → H₂O + Br reveals the steric effect which clarifies branching mechanisms. Collisions at O‐end of OH lead to direct H₂O formation while H‐end of OH reacts via indirect migration mechanism. A roaming pathway is observed along with transition‐state pathway in photodissociation of methyl formate HCOOCH₃ which can be a unimolecular version of branching dynamics at the molecular level. For more details on this figure, please see pp 567～582 in this issue.