Measurement of the Excited-State Molecular Polarizability of C60

1994 ◽  
Vol 359 ◽  
Author(s):  
N. Tang ◽  
R. W. Hellwarth ◽  
J. P. Partanen
Keyword(s):  
Excited State ◽  
Cross Section ◽  
Benzene Solution ◽  
Excited State Absorption ◽  
Molecular Polarizability ◽  
Wave Mixing ◽  
Pump Probe ◽  
Probe Experiment ◽  
Pump Probe Experiment ◽  
532 Nm

ABSTRACTWe use ∼30 ps pulses at 532 nm to measure the complex excited-state molecular polarizability αe in a C60/benzene solution. We determine the imaginary part of αe by measuring the excited-state absorption cross-section in a pump-probe experiment. In a degenerate-four-wave-mixing (DFWM) experiment, we find that in delayed probing of the complex index gratings formed by ∼30 ps pulses, the thermal and the excited-state polarizability changes both contribute to these transient gratings.

The Characteristics of All-Optical Switching and Modulation in Phenoxy-Phthalocyanines Liquid

2013 ◽  
Vol 284-287 ◽  
pp. 2830-2834
Author(s):  
Yun Dong Zhang ◽  
Cheng Bao Yao ◽  
Hai Tao Yin ◽  
Chang Qiu Yu ◽  
Jin Li ◽  
...  
Keyword(s):  
Excited State ◽  
Light Intensity ◽  
Response Time ◽  
Optical Switching ◽  
Pump Light ◽  
Pump Probe ◽  
All Optical ◽  
Probe Experiment ◽  
Pump Probe Experiment ◽  
All Optical Switching

We present our experimental results on the measurements of excited state dynamics in 2, 9, 16, 23-phenoxy-phthalocyanine (Pc1) and 2, 9, 16, 23-phenoxy-phthalocyanine-zinc (Pc2) using the pump-probe experiment. The results show that the All-Optical Switching (A-OS) response time of Pc2 longer than that of Pc1, and switch-off and -on times of A-OS for Pc2 are 1.2 and 11.6 μs and for Pc1 are 2.3 and 7.8 μs at the same intensity. Moreover, analysis of modulation characteristics of A-OS shows that the stronger the light intensity of the pump light is, the smaller the normalized transmittance is and the shorter the response time of A-OS is. The consequences of such short lifetimes are also discussed in view of the strong A-OS properties of these molecules.

scholarly journals Effective data collection and refinement of pertubated structures

2014 ◽  
Vol 70 (a1) ◽  
pp. C1750-C1750
Author(s):  
Pascal Parois ◽  
Richard Cooper
Keyword(s):  
Excited State ◽  
Data Collection ◽  
Least Squares ◽  
Time Resolved ◽  
Pump Probe ◽  
Partial Data ◽  
Mixed Oxidation ◽  
Probe Experiment ◽  
Pump Probe Experiment

Approaches to determining the influence of individual measurements on the precision of crystallographic least squares parameters have been known for a long while.[1] Situations in which the precision of a single parameter (or linear combination of parameters) is critical can include: determination of novel bond lengths; refinement of site occupancies in mixed metal or mixed oxidation state systems; determination of the fraction of excited state molecules in a time-resolved pump-probe experiment. Such calculations are easily applicable to point-detector instruments, where individual influential reflections could be remeasured one-by-one. However, on a modern area detector instrument many reflections are measured on one frame and therefore some consideration of the appropriate strategy of reciprocal space scans is permitted to allow a more efficient use of the instrument. The highly influential partial data collection is then feed into an appropriate refinement model. Occupancies in mixed-metal or mixed-oxidation state systems and fractions and positions of excited state molecules during a time-resolved pump-probe experiment can be determined using direct refinement of the perturbation of the structure from the ground state. Re-factoring to modern Fortran of the Crystals software is in progress to allow the implementation of new algorithms such as a difference refinement.[2] We present an analysis of diffractometer strategy selection to prioritize scans which give the best improvement in specific least-squares parameters and a novel algorithm for the refinement of the partial data using crystals.

Synthesis and Optical Limiting Characterization of a Porphyrin-Buckminsterfullerene Dyad

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.

Collinear pump probe experiment, novel approach to ultrafast spectroscopy

1999 ◽  
Vol 68 (4) ◽  
pp. 689-692 ◽  
Author(s):  
B. Bousquet ◽  
L. Canioni ◽  
J. Plantard ◽  
L. Sarger
Keyword(s):  
Ultrafast Spectroscopy ◽  
Pump Probe ◽  
Novel Approach ◽  
Probe Experiment ◽  
Pump Probe Experiment

scholarly journals Probing calculatedO2+potential-energy curves with an XUV-IR pump-probe experiment

2015 ◽  
Vol 91 (4) ◽  
Author(s):  
Philipp Cörlin ◽  
Andreas Fischer ◽  
Michael Schönwald ◽  
Alexander Sperl ◽  
Tomoya Mizuno ◽  
...  
Keyword(s):  
Potential Energy ◽  
Potential Energy Curves ◽  
Pump Probe ◽  
Probe Experiment ◽  
Pump Probe Experiment

Photophysics and reverse saturable absorption of cationic dinuclear iridium(iii) complexes bearing fluorenyl-tethered 2-(quinolin-2-yl)quinoxaline ligands

2021 ◽  
Author(s):  
Cuifen Lu ◽  
Taotao Lu ◽  
Peng Cui ◽  
Svetlana Kilina ◽  
Wenfang Sun
Keyword(s):  
Excited State ◽  
Excited State Absorption ◽  
Saturable Absorption ◽  
Reverse Saturable Absorption ◽  
Triplet Excited State ◽  
532 Nm

Dinuclear Ir(iii) complexes tethered by fluorenyl motif exhibited weak 1,3MLCT/1,3LLCT absorption at >500 nm, dual phosphorescence, broad triplet excited-state absorption, and reverse saturable absorption at 532 nm.

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