Tetrabrominated Lead Naphthalocyanine for Optical Power Limiting |
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| Authors: | Danilo Dini Dr Moreno Meneghetti Prof Mario J F Calvete Dr Thomas Arndt Dr Colin Liddiard Dr Michael Hanack Prof Dr |
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| Institution: | 1. Institute of Organic Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076 Tübingen (Germany), Fax: (+49)?7071‐295268;2. Department of Chemical Sciences, University of Padua, Via Marzolo 1, 35131 Padua (Italy), Fax: (+39)?049‐8275239;3. Degussa‐R?hm GmbH, Analytical Services, Kirschenallee, 64293 Darmstadt (Germany) |
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| Abstract: | The complex 2,(3)‐tetrabromo‐3,(2)‐tetra(3,5‐di‐tert‐butyl)phenyloxy]‐naphthalocyaninato lead Br4(tBu2C6H3O)4NcPb, 1 ] has been prepared and its optical limiting properties for ns light pulses have been measured. Complex 1 behaves as a reverse saturable absorber within the spectral range 440–720 nm with a limiting threshold of 0.1 J cm?2 at 532 nm. The lifetime of the absorbing triplet excited state has been evaluated as 3.8×10?7 s and the quantum yield of triplet formation has been measured as 0.07 in toluene. The nonlinear optical transmission properties of complex 1 have also been determined in Plexiglas naphthalocyanine content: 5.0×10?4 M (0.1 % by weight)]. A reversible nonlinear absorption was again observed for a fluence above 0.4 J cm?2, but through different excited‐state dynamics. This may be rationalized in terms of aggregation of the molecule in the polymer matrix. |
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| Keywords: | lead naphthalocyanines nonlinear optics optical power limiting transient spectroscopy |
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