Time-resolved EPR spectra of a photoexcited phenanthrene-linked copper(II)-free-base porphyrin dimer: An intermediate-coupling case in a triplet-doublet spin system

2003 ◽  
Vol 23 (3-4) ◽  
pp. 393-407 ◽  
Author(s):  
M. Asano-Someda ◽  
N. Toyama ◽  
Y. Kaizu
Keyword(s):  
Spin System ◽  
Epr Spectra ◽  
Free Base ◽  
Intermediate Coupling ◽  
Time Resolved ◽  
Coupling Case ◽  
Porphyrin Dimer

A time-resolved ESR study on triplet-triplet energy transfer processes in a copper(II)-free-base porphyrin dimer

1994 ◽  
Vol 132 ◽  
pp. 243-248 ◽  
Author(s):  
Motoko Asano-Someda ◽  
Takatoshi Ichino ◽  
Youkoh Kaizu
Keyword(s):  
Energy Transfer ◽  
Free Base ◽  
Triplet Energy ◽  
Time Resolved ◽  
Transfer Processes ◽  
Triplet Energy Transfer ◽  
Porphyrin Dimer

scholarly journals Synthesis, Biomacromolecular Interactions, Photodynamic NO Releasing and Cellular Imaging of Two [RuCl(qn)(Lbpy)(NO)]X Complexes

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2545
Author(s):  
Luna Song ◽  
Hehe Bai ◽  
Chenyang Liu ◽  
Wenjun Gong ◽  
Ai Wang ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Confocal Imaging ◽  
Epr Spectra ◽  
Distorted Octahedral Geometry ◽  
Ionization Mass ◽  
Time Resolved ◽  
Pbr322 Dna ◽  
Vis Spectroscopy ◽  
No Release ◽  
Ft Ir

Two light-activated NO donors [RuCl(qn)(Lbpy)(NO)]X with 8-hydroxyquinoline (qn) and 2,2′-bipyridine derivatives (Lbpy) as co-ligands were synthesized (Lbpy1 = 4,4′-dicarboxyl-2,2′-dipyridine, X = Cl− and Lbpy2 = 4,4′-dimethoxycarbonyl-2,2′-dipyridine, X = NO3−), and characterized using ultraviolet–visible (UV-vis) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, nuclear magnetic resonance (1H NMR), elemental analysis and electrospray ionization mass spectrometry (ESI-MS) spectra. The [RuCl(qn)(Lbpy2)(NO)]NO3 complex was crystallized and exhibited distorted octahedral geometry, in which the Ru–N(O) bond length was 1.752(6) Å and the Ru–N–O angle was 177.6(6)°. Time-resolved FT-IR and electron paramagnetic resonance (EPR) spectra were used to confirm the photoactivated NO release of the complexes. The binding constant (Kb) of two complexes with human serum albumin (HSA) and DNA were quantitatively evaluated using fluorescence spectroscopy, Ru-Lbpy1 (Kb~106 with HSA and ~104 with DNA) had higher affinity than Ru-Lbpy2. The interactions between the complexes and HSA were investigated using matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS) and EPR spectra. HSA can be used as a carrier to facilitate the release of NO from the complexes upon photoirradiation. The confocal imaging of photo-induced NO release in living cells was successfully observed with a fluorescent NO probe. Moreover, the photocleavage of pBR322 DNA for the complexes and the effect of different Lbpy substituted groups in the complexes on their reactivity were analyzed.

Synthesis and Photophysical Properties of a Conformationally Flexible Mixed Porphyrin Star-Pentamer

2009 ◽  
Vol 62 (7) ◽  
pp. 692 ◽  
Author(s):  
Toby D. M. Bell ◽  
Sheshanath V. Bhosale ◽  
Kenneth P. Ghiggino ◽  
Steven J. Langford ◽  
Clint P. Woodward
Keyword(s):  
Energy Transfer ◽  
Photophysical Properties ◽  
Fluorescence Decay ◽  
High Yield ◽  
Free Base ◽  
Time Resolved ◽  
Zinc Porphyrin ◽  
Relative Contribution ◽  
Synthetic Strategy ◽  
Decay Times

The synthesis of a porphyrin star-pentamer bearing a free-base porphyrin core and four zinc(ii) metalloporphyrins, which are tethered by a conformationally flexible linker about the central porphyrin’s antipody, is described. The synthetic strategy is highlighted by the use of olefin cross metathesis to link the five chromophores together in a directed fashion in high yield. Photoexcitation into the Soret absorption band of the zinc porphyrin chromophores at 425 nm leads to a substantial enhancement of central free-base porphyrin fluorescence, indicating energy transfer from the photoexcited zinc porphyrin (outer periphery) to central free-base porphyrin. Time-resolved fluorescence decay profiles required three exponential decay components for satisfactory fitting. These are attributed to emission from the central free-base porphyrin and to two different rates of energy transfer from the zinc porphyrins to the free-base porphyrin. The faster of these decay components equates to an energy-transfer rate constant of 3.7 × 109 s–1 and an efficiency of 83%, whereas the other is essentially unquenched with respect to reported values for zinc porphyrin fluorescence decay times. The relative contribution of these two components to the initial fluorescence decay is ~3:2, similar to the 5:4 ratio of cis and trans geometric isomers present in the pentamer.

scholarly journals Singlet oxygen generation properties of an inclusion complex of cyclic free-base porphyrin dimer and fullerene C60

RSC Advances ◽  
2017 ◽  
Vol 7 (30) ◽  
pp. 18690-18695 ◽  
Author(s):  
Yousuke Ooyama ◽  
Toshiaki Enoki ◽  
Joji Ohshita ◽  
Takuya Kamimura ◽  
Shuwa Ozako ◽  
...  
Keyword(s):  
Inclusion Complex ◽  
Visible Light ◽  
Singlet Oxygen ◽  
Visible Light Irradiation ◽  
Fullerene C60 ◽  
Light Irradiation ◽  
Free Base ◽  
Oxygen Generation ◽  
Singlet Oxygen Generation ◽  
Porphyrin Dimer

We demonstrate that a cyclic free-base porphyrin dimer and its inclusion complex with fullerene C60 possess the ability to generate singlet oxygen (1O2) under visible light irradiation.

THEORY OF EXCITATION ENERGY TRANSFER IN THE INTERMEDIATE COUPLING CASE AND ITS APPLICATION TO THE PHOTOSYNTHETIC ANTENNA SYSTEMS

2001 ◽  
Vol 15 (28n30) ◽  
pp. 3833-3836 ◽  
Author(s):  
AKIHIRO KIMURA ◽  
TOSHIAKI KAKITANI ◽  
TAKAHISA YAMATO
Keyword(s):  
Energy Transfer ◽  
Excitation Energy ◽  
Excitation Energy Transfer ◽  
Analytical Formula ◽  
Expansion Method ◽  
Time Correlation ◽  
Intermediate Coupling ◽  
Coupling Case ◽  
Photosynthetic Antenna ◽  
Antenna Systems

We developed the theory of excitation energy transfer (EET) in the intermediate coupling case using the decoupling procedure. We succeeded in treating the theory analytically by assuming that the two-time correlation function is represented as an exponential function. We examined the validity of its approximation. We calculated the time dependent probability na(t) of the EET, in which the acceptor molecule is in the excited state by making alternative calculation of the cumulant expansion method. Applying this calculation by this method to the photosynthetic antenna systems and comparing its result with the analytical formula, we found that these results coincide well with each other in the due time region of the approximation.

scholarly journals Dye-sensitized solar cell based on an inclusion complex of a cyclic porphyrin dimer bearing four 4-pyridyl groups and fullerene C60

RSC Advances ◽  
2016 ◽  
Vol 6 (20) ◽  
pp. 16150-16158 ◽  
Author(s):  
Yousuke Ooyama ◽  
Koji Uenaka ◽  
Takuya Kamimura ◽  
Shuwa Ozako ◽  
Masahiro Kanda ◽  
...  
Keyword(s):  
Solar Cell ◽  
Dye Sensitized Solar Cells ◽  
Fullerene C60 ◽  
Dye Sensitized Solar Cell ◽  
Free Base ◽  
New Class ◽  
Dye Sensitized ◽  
Sensitized Solar Cells ◽  
Porphyrin Dimers ◽  
Porphyrin Dimer

Cyclic free-base porphyrin dimers linked by butadiyne or phenothiazine bearing four 4-pyridyl groups and their inclusion complexes with fullerene C60 have been applied to dye-sensitized solar cells as a new class of porphyrin dye sensitizers.

Time-Resolved EPR Spectra of Spin-Correlated Radical Pairs: Spectral and Kinetic Modulation Resulting from Electron−Nuclear Hyperfine Interactions

2010 ◽  
Vol 114 (1) ◽  
pp. 162-171 ◽  
Author(s):  
Qixi Mi ◽  
Mark A. Ratner ◽  
Michael R. Wasielewski
Keyword(s):  
Hyperfine Interactions ◽  
Epr Spectra ◽  
Radical Pairs ◽  
Time Resolved

Triplet-triplet energy transfer in a copper(II) porphyrin-free-base porphyrin dimer

1987 ◽  
Vol 91 (16) ◽  
pp. 4269-4273 ◽  
Author(s):  
Osamu. Ohno ◽  
Yoshiharu. Ogasawara ◽  
Motoko. Asano ◽  
Yoshizumi. Kajii ◽  
Youkoh. Kaizu ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Free Base ◽  
Triplet Energy ◽  
Triplet Energy Transfer ◽  
Porphyrin Dimer
Sign in / Sign up

Export Citation Format

Share Document