Spectroscopic characterization of excited-state absorption in Co:ZnSe/ZnS crystals (Conference Presentation)

The synthesis and characterization of a series of 3,5-di-[Formula: see text]-benzyloxystyrylBODIPY dyes with different substituents at the meso-aryl position is reported. The photophysical and nonlinear optical properties are described. BODIPYs of this type are found to be suitable for optical limiting at 532 nm on the nanosecond timescale. An enhancement of the population of the T[Formula: see text] state through the incorporation of bromine atoms at the 2,6-positions does not result in an enhancement of the optical limiting properties on a nanosecond timescale. This suggests that, in contrast with phthalocyanines, access to excited state absorption (ESA) from the T[Formula: see text] state through the introduction of a heavy atom effect does not provide a significantly improved reverse saturable absorbance response compared to ESA from the S[Formula: see text] state.

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Synthesis and Optical Limiting Characterization of a Porphyrin-Buckminsterfullerene Dyad

MRS Proceedings ◽

10.1557/proc-561-81 ◽

1999 ◽

Vol 561 ◽

Author(s):

Kenneth J. McEwan ◽

Keith L. Lewis ◽

How-Ghee Ang ◽

Zhi-Heng Loh ◽

Leng-Leng Chng ◽

...

Keyword(s):

Excited State ◽

Cross Section ◽

Excited State Absorption ◽

Optical Limiting ◽

Azomethine Ylide ◽

Absorption Cross ◽

Model Compounds ◽

Close Proximity ◽

532 Nm

ABSTRACTThe optical limiting performances of donor-buckminsterfullerene (C60) dyads have hitherto been unreported. The predicted large excited state absorption cross-section of such dyads in their charge-separated states would enable them to exhibit enhanced optical limiting relative to their individual components. We report herein the synthesis and optical limiting characterization of a novel porphyrin-buckminsterfullerene dyad, in which the porphyrin and C60 moieties are held within close proximity of one another by an o-phenylene bridge. The porphyrin-C60 dyad was synthesized via 1,3-dipolar azomethine ylide cycloaddition, and was obtained in 37.0% yield. Optical limiting measurements at 532 nm using 3-ns pulses show that the limiting performance of the dyad is poorer compared to its model compounds. Possible reasons for the worsened performance of the dyad will be discussed.

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A new source for vibrationally excited and rotationally cold metal-oxide molecules: spectroscopic characterization of the low-lying a3Π2 metastable excited state of the MgO molecule

Chemical Physics Letters ◽

10.1016/j.cplett.2003.09.112 ◽

2003 ◽

Vol 381 (3-4) ◽

pp. 381-384 ◽

Cited By ~ 6

Author(s):

D. Bellert ◽

Katherine L. Burns ◽

Nguyen-Thi Van-Oanh ◽

Jinjin Wang ◽

W.H. Breckenridge

Keyword(s):

Excited State ◽

Metal Oxide ◽

Spectroscopic Characterization ◽

Vibrationally Excited ◽

Cold Metal

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Single-wall carbon nanotube porphyrin nanoconjugates

Journal of Porphyrins and Phthalocyanines ◽

10.1142/s1088424607000503 ◽

2007 ◽

Vol 11 (06) ◽

pp. 442-447 ◽

Cited By ~ 12

Author(s):

Christian Ehli ◽

Stéphane Campidelli ◽

Fulvio G. Brunetti ◽

Maurizio Prato ◽

Dirk M. Guldi

Keyword(s):

Excited State ◽

Carbon Nanotube ◽

Transient Absorption ◽

Spectroscopic Characterization ◽

Single Wall Carbon Nanotube ◽

Single Wall Carbon ◽

Low Degree ◽

Donor Acceptor ◽

Covalently Linked

We describe the synthesis, microscopic and spectroscopic characterization of a novel donor-acceptor prototype, namely, a single wall carbon nanotube (SWNT) nanoconjugate bearing a covalently linked free base porphyrin ( H 2 P ). In the characterized SWNT- H 2 P nanoconjugate the electronic features of SWNT are largely retained, when compared to pristine SWNT. In fact, carefully controlled reaction conditions lead to a low degree of SWNT functionalization, as evidenced by the preservation of the SWNT van Hove singularities. As a consequence, the overall SWNT loading with H 2 P is so low that in the ground state, the H 2 P features are barely seen, which is different from the excited state, where features of H 2 P are clearly discernable. For example, fluorescence and transient absorption characteristics corroborate, unequivocally, the formation of the H 2 P singlet excited state, which is, however, impacted by the presence of SWNT.

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