Observation and decay of free and ligated metalloporphyrins in the gas phase

A soft desorption technique has been tested in order to vaporize metalloporphyrins in a supersonic jet and study their energetics and dynamics in the gas phase at low temperatures. Several metalloporphyrins: ZnTPP, NiTPP, CoTPP and ligated RuTPP–CO have been detected by resonant 2 photon ionization. ZnTPP was observed with high sensitivity owing to its long S1 lifetime, while the transition metal porphyrins displayed less intense ion yields due to short excited state lifetimes. The ligated ruthenium complex could be observed intact and femtosecond excitation at 400 nm revealed the ultrashort excited state dissociation of the ruthenium metalloporphyrin.