Synthesis and photophysical properties of a [60]fullerene compound with dimethylaniline and ferrocene connected through a pyrazolino group: a study by laser flash photolysis

2006 ◽  
Vol 8 (35) ◽  
pp. 4104-4111 ◽  
Author(s):  
Juan L. Delgado ◽  
Mohamed E. El-Khouly ◽  
Yasuyuki Araki ◽  
María J. Gómez-Escalonilla ◽  
Pilar de la Cruz ◽  
...  
Keyword(s):  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Photophysical Properties ◽  
Laser Flash ◽  
Group A

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

Photophysical properties of gatifloxacin in aqueous solution by laser flash photolysis and pulse radiolysis

2012 ◽  
Vol 81 (1) ◽  
pp. 40-45 ◽  
Author(s):  
Haixia Li ◽  
Peng Zhang ◽  
Yancheng Liu ◽  
Ruizhi Tang ◽  
Zhaoguo Xing ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Pulse Radiolysis ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Photophysical Properties ◽  
Laser Flash

Photophysical Properties of the Newly Synthesized Triad Based on [70]Fullerene Studies with Laser Flash Photolysis

2007 ◽  
Vol 111 (17) ◽  
pp. 4335-4341 ◽  
Author(s):  
Frédéric Oswald ◽  
Mohamed E. El-Khouly ◽  
Yasuyuki Araki ◽  
Osamu Ito ◽  
Fernando Langa
Keyword(s):  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Photophysical Properties ◽  
Laser Flash

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.

Reaction of the tamoxifen cation and the bis-(4-methoxyphenyl)methyl cation in aqueous solutions containing 2'-deoxyguanosine

2002 ◽  
Vol 80 (3) ◽  
pp. 269-280 ◽  
Author(s):  
Robert A McClelland ◽  
Cristina Sanchez ◽  
Effiette Sauer ◽  
Sinisa Vukovic
Keyword(s):  
Aqueous Solutions ◽  
Rate Constant ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Laser Flash ◽  
High Rate ◽  
Group A ◽  
Stable Product ◽  
High Concentrations ◽  
Conjugate Base

The competition between 2'-deoxyguanosine (dG) and water has been quantitatively evaluated for the allylic carbocation derived from tamoxifen and for the stabilized diarylmethyl cation (bis-(4-methoxyphenyl)methyl). Both systems were examined by the competition kinetics method, in which the products were quantitatively analyzed after the SN1 solvolysis of the corresponding acetate esters in aqueous solutions containing the nucleoside. The principal product of the reaction of both cations with dG is the adduct at the NH2 group, a characteristic of delocalized carbocations. The tamoxifen cation was also examined by laser flash photolysis, with absolute rate constants for the reaction with dG and water being obtained and converted into rate constant ratios. The principal result of this study is that there is a three orders of magnitude difference in the reactivity of these cations towards the neutral form of dG and its conjugate base. Under acidic conditions where the reaction occurs with neutral dG, the guanine–water selectivity is low. Even at relatively high concentrations of dG, the majority of the product is alcohol derived from the water reaction. At pH 10 to 11, in contrast, dG is present as the anion and this is highly competitive. Yields of adduct as high as 90% can be attained. A consequence of the large difference in reactivities is that at neutral pH the majority of the reaction of the cation with dG is actually occurring via the small amount of conjugate base present. A further feature of the results is that the NH2 adduct is the predominant stable product from the anion. To explain the high rate constant for the reaction forming this product, a mechanism is proposed whereby one of the protons of the NH2 group is transferred to N1 as the N2-cation bond is forming.Key words: guanine, DNA adduct, carbocation, tamoxifen.

Photophysical Properties of C60(C6H5)5Cl:  A Laser Flash Photolysis and Pulse Radiolysis Study

1997 ◽  
Vol 101 (30) ◽  
pp. 5418-5422 ◽  
Author(s):  
Dipak K. Palit ◽  
H. Mohan ◽  
Paul R. Birkett ◽  
Jai P. Mittal
Keyword(s):  
Pulse Radiolysis ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Photophysical Properties ◽  
Laser Flash
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