Ultrafast Intersystem Crossing: Excited State Dynamics of Platinum Acetylide Complexes

Femtosecond time-resolved fluorescence and transient absorption measurements have been carried out on a series of platinum acetylide complexes to unravel the dynamics of intersystem crossing and the formation of triplet states in real time as a function of chain length. Ultrafast inter system crossing with a time constant less than 100 fs has been observed for the case of short chain length platinum acetylide complex and this time constant increases with increasing the chain length. Apart from the singlet to triplet intersystem crossing, additional triplet state relaxation has also been observed which happens in picosecond time scale.