Photodissociation pathways of gas-phase photoactive yellow protein chromophores.

The absorption dynamics of two model chromophores of the photoactive yellow protein were studied in gas-phase experiments. Using different time-resolving techniques with an overall sensitivity ranging from seconds down to a few nanoseconds, complex dynamics were revealed for the p -coumaric acid anion, involving both fragmentation and electron detachment as possible photoresponse channels. For the trans-thiophenyl-p-coumarate model, despite its more complex molecular structure, simpler decay dynamics showing only fragmentation were observed.