Abstract
The singlet excited-state lifetime of a bipyridyl platinum(II) complex containing two alkynyl-benzothiazolylfluorene units was determined to be by fitting femtosecond transient difference absorption data, and the triplet quantum yield was measured to be 0.14. A ground-state absorption cross section of at 532 nm was deduced from UV-visible absorption data. Excited-state absorption cross sections of (singlet) and (triplet) were obtained by using a five-level dynamic model to fit open-aperture Z scans at picosecond and nanosecond pulse widths and a variety of pulse energies. For this complex, the ratio of the triplet excited-state absorption cross section to the ground-state absorption cross section—long used as a figure of merit for reverse saturable absorbers—thus stands at 754, to our knowledge the largest ever reported at 532 nm wavelength.
© 2010 Optical Society of America
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