text: Fluorenylidene can be produced by photolysis of 9-diazofluorene (DAF). 
  Ultra-fast (300 fs) time resolved laser-flash photolysis of DAF implicates a four-step process in the formation of fluorenylidene by irradiation of 9-diazofluorene. 
  # Irradiation of DAF initially yields an excited singlet state diazofluorene 	molecule ( DAF*)
  # DAF* decays to form the open shell carbene,FL*, as the minor product, 	and the less energetic closed shell carbene, FL, as the major product. 
  # Any excited singlet FL* in solution relaxes to the lower energy singlet 	state FL (20.9 ps) 
  # FL equilibrates with the ground state triplet FL by intersystem crossing.