The organo-transition metal complexes (Ni or Pt)bis(3,4-toluenediimine), Ni-bis(3,4-benzophenonediimine) and Ni-bis(1-phenyl-2-butyl-1,2-dithiolene), which are generally considered good candidates for third order nonlinear optical (NLO) applications, have been examined by subpicosecond induced transparency measurements. The electronic decay times are around 2ns for each of the compounds, while the orientational relaxation happens in the 100ps range. High third order NLO parameters have been previously reported from degenerate four wave mixing experiments, but not confirmed by several other techniques. This disparity in results is clarified here in terms of noninstantaneous contributions from real electronic excitations.
Published in Chem. Phys. Lett. 254(1996) 410-414
Reprinted with kind permission from Elsevier Science - NL, Amsterdam, the Netherlands, publishers Chemical Physics Letters.