Structure Property Characterization of Nonlinear Optical Materials

2004 ◽  
Vol 846 ◽  
Author(s):  
Joy E. Rogers ◽  
Jonathan E. Slagle ◽  
Daniel G. McLean ◽  
Benjamin C. Hall ◽  
Thomas M. Cooper ◽  
...  
Keyword(s):  
Nonlinear Optical ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Photophysical Properties ◽  
Excited State Absorption ◽  
Laser Flash ◽  
Nanosecond Laser ◽  
Structure Property ◽  
Absorption Properties ◽  
Structure Property Relationships

ABSTRACTThis research is comprised of understanding the linear photophysical properties of various dyes to better understand the more complicated nonlinear optical properties. Determining structure property relationships of a series of structurally closely related chromophores is the key in understanding the drivers for the various photophysical properties. In this paper we survey the effect of physically changing the Pt poly-yne structure on the S0-S1 and T1-Tn absorption properties for each of the chromophores. A series of structurally modified platinum poly-ynes have been studied using experimental methods including UV/Vis absorption and nanosecond laser flash photolysis. We found that with extension of the ligand length both the ground and triplet excited state absorption shift to lower energies. Comparing the absorption properties of the ligands and butadiynes with the platinum containing versions reveal that the S1 and Tn exciton is localized on one portion of the ligand with extension and not conjugated through the whole molecule. Changing the phosphine R group results in little effect to the absorption properties except when the R group is conjugated in the case of phenyl. However, changing the R group results in varied materials properties.

Substituted Phosphorous Triazatetrabenzocorroles: Correlation Between Structure and Excited State Properties

2009 ◽  
Vol 62 (5) ◽  
pp. 434 ◽  
Author(s):  
Xian-Fu Zhang ◽  
Yakuan Chang ◽  
Yanling Peng ◽  
Fushi Zhang
Keyword(s):  
Quantum Yield ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Photophysical Properties ◽  
Laser Flash ◽  
Time Resolved Fluorescence ◽  
Absorption Properties ◽  
Strong Electron ◽  
Time Resolved ◽  
Triplet Formation

The photophysical properties of five novel phthalocyanine analogues, dihydroxy phosphorus(v) triazatetrabenzocorrole (PTBC) substituted with –NO2, –SO3H, OiPr, and –NH2, respectively, were studied by a combination of absorption, steady-state emission, time-resolved fluorescence, and laser flash photolysis. All substituents, even for the strong electron-donating –NH2, cause only a slight red shift of their absorption and emission maxima. These complexes are generally monomeric in organic solution, whereas the sulfonated derivative, PTBC(SO3H)4, slightly aggregates in aqueous buffer. Distinct from phthalocyanines, PTBCs substituted with –NO2 or –NH2 still show high photo activities. The electron-withdrawing –NO2 and –SO3H decrease the fluorescence quantum yield but increase the triplet formation yield to 0.76 and 0.82, respectively. All PTBCs have long triplet lifetimes and hence generate singlet oxygen efficiently with a quantum yield from 0.43 to 0.75. Together with the ground-state absorption properties, the results suggest that these PTBCs may be used as excellent photosensitizers for photodynamic therapy.

Effect of β-bromo substitution on the photophysical properties of meso-phenyl, meso-carbazole, and meso-triphenylamine porphyrins

2012 ◽  
Vol 16 (04) ◽  
pp. 370-379 ◽  
Author(s):  
Joy E. Haley ◽  
Weijie Su ◽  
Kristi M. Singh ◽  
Jennifer L. Monahan ◽  
Jonathan E. Slagle ◽  
...  
Keyword(s):  
Near Infrared ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Photophysical Properties ◽  
Heavy Atom ◽  
Nanosecond Laser ◽  
Free Base ◽  
Structure Property ◽  
Absorption Data ◽  
Absorption And Emission

We present results of an experimental photophysical study of a series of novel brominated and non-brominated porphyrins that contain phenyl, carbazole, or triphenylamine in the meso-position. In addition we have looked at the effects of incorporating a zinc metal into the porphyrin system relative to the free base. Structure-property relationships are established using various absorption and emission techniques including femtosecond pump probe transient absorption and nanosecond laser flash photolysis. With slightly increasing electron donating strength (phenyl < carbazole < triphenylamine) red shifts were observed in all data. The same effect was observed upon the addition of bromine in the beta position. Due to the heavy atom affect of the bromines both the singlet and triplet excited state lifetimes were significantly shorter in the brominated porphyrins. For the T1–Tn absorption data we observe a large absorption in the near infrared region with the brominated carbazole and triphenylamine. The largest effect of the addition of zinc was in the ground state absorption and emission where a blue shift in the data was observed. Some effects were also observed in the kinetic decays with zinc as the metal compared to the free base porphyrins.

scholarly journals Onium salts improve the kinetics of photopolymerization of acrylate activated with visible light

RSC Advances ◽  
2020 ◽  
Vol 10 (42) ◽  
pp. 24817-24829 ◽  
Author(s):  
Janina Kabatc ◽  
Katarzyna Iwińska ◽  
Alicja Balcerak ◽  
Dominika Kwiatkowska ◽  
Agnieszka Skotnicka ◽  
...  
Keyword(s):  
Steady State ◽  
Visible Light ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Laser Flash ◽  
Nanosecond Laser ◽  
Chemical Mechanisms ◽  
Onium Salts ◽  
Nanosecond Laser Flash Photolysis ◽  
Kinetics Of

The chemical mechanisms were investigated by steady state photolysis and nanosecond laser flash photolysis experiments. A mechanism for initiating polymerization using both onium salts is proposed here.

scholarly journals Combining Defects in a Single Nanographene: A Fully Helical Saddle Ribbon

Synlett ◽  
2019 ◽  
Vol 30 (09) ◽  
pp. 997-1002 ◽  
Author(s):  
Carlos Cruz ◽  
Silvia Castro-Fernández ◽  
Ermelinda Maçôas ◽  
Alba Millán ◽  
Araceli Campaña
Keyword(s):  
Organic Synthesis ◽  
Carbon Nanostructures ◽  
Nonlinear Optical ◽  
Photophysical Properties ◽  
Structure Property ◽  
Chiroptical Properties ◽  
Curved Structures ◽  
Structure Property Relationships ◽  
Linear And Nonlinear ◽  
Controlled Preparation

The controlled preparation of well-defined distorted nanographenes by a bottom-up approach based on organic synthesis permits the direct establishment of unprecedented structure–property relationships in carbon nanostructures. The simultaneous incorporation of various defects in nanographenes affords highly curved structures with novel or enhanced photophysical properties. In this sense, we recently reported a fully helical and saddle-shaped nanographene ribbon containing the first undecabenzo[7]helicene unit. Both its linear and nonlinear optical properties are enhanced in comparison with those of other partially π-extended [7]helicenes. Moreover, the new superhelicene exhibits the highest emission dissymmetry factor (g lum) reported to date for a homochiral nanographene. The combination of both nonlinear and chiroptical properties in nanographenes opens up new possible future applications for those distorted nanostructures.1 Introduction2 Synthesis of Embedded Seven-Membered Rings3 Combination of Defects: Seven-Membered Rings and π-Extended Helicenes4 Conclusions and Outlook

Photochemical and Photophysical Properties of C60Dendrimers Studied by Laser Flash Photolysis

2002 ◽  
Vol 106 (29) ◽  
pp. 7193-7199 ◽  
Author(s):  
Ryouta Kunieda ◽  
Mamoru Fujitsuka ◽  
Osamu Ito ◽  
Miho Ito ◽  
Yasujiro Murata ◽  
...  
Keyword(s):  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Photophysical Properties ◽  
Laser Flash

Synthesis and Characterization of Novel Platinum Acetylide Oligomers

2003 ◽  
Vol 771 ◽  
Author(s):  
Thomas M. Cooper ◽  
Benjamin C. Hall ◽  
Daniel G. McLean ◽  
Joy E. Rogers ◽  
Aaron R. Burke ◽  
...  
Keyword(s):  
Absorption Spectra ◽  
Ground State ◽  
Near Infrared ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Laser Flash ◽  
Structure Property ◽  
Ground State Absorption ◽  
Excitation Spectra ◽  
C Nmr

AbstractAs part of an effort to develop a spectroscopic structure-property relationship in platinum acetylide oligomers, we have prepared a series of bidentate Pt(PBu3)2L2 compounds. The ligand was the series o-syd-C6H4-CΞC-(C6H4-CΞC)n-H, n = 0,1,2. The terminal oligomer unit consisted of a sydnone group ortho to the acetylene carbon. The compounds were characterized by various methods, including 13C-NMR, ground state absorption, fluorescence, phosphorescence and laser flash photolysis. The acetylenic 13C-NMR resonances showed sydnone influences that decreased with increasing number of monomer units. The ground state absorption spectra were slightly red shifted from those of the baseline oligomers not having a sydnone group. The low temperature emission and excitation spectra showed complex dependence on excitation and emission wavelengths, suggesting the chromphores resided in a distribution of solvent environments and conformations. Finally, broad triplet state absorption spectra were observed, with absorption throughout the visible and near infrared regions.

Photocatalytic Electron Transfer in Hybrid Titania Nanosheets Studied by Nanosecond Laser Flash Photolysis

2005 ◽  
Vol 34 (11) ◽  
pp. 1522-1523 ◽  
Author(s):  
Takashi Tachikawa ◽  
Tatsuto Yui ◽  
Mamoru Fujitsuka ◽  
Katsuhiko Takagi ◽  
Tetsuro Majima
Keyword(s):  
Electron Transfer ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Laser Flash ◽  
Nanosecond Laser ◽  
Nanosecond Laser Flash Photolysis
Sign in / Sign up

Export Citation Format

Share Document