Synthesis, electrochemistry, spectroscopy and photophysical properties of a series of meso-phenylpyridylporphyrins with one to four pyridyl rings coordinated to [Ru(bipy)2Cl]+ groups

2002 ◽  
Vol 06 (01) ◽  
pp. 33-42 ◽  
Author(s):  
Fábio M. Engelmann ◽  
Pellegrino Losco ◽  
Herbert Winnischofer ◽  
Koiti Araki ◽  
Henrique E. Toma
Keyword(s):  
Energy Transfer ◽  
Quantum Yield ◽  
Electrochemical Behavior ◽  
Fluorescence Quantum Yield ◽  
Photophysical Properties ◽  
Intramolecular Energy Transfer ◽  
Porphyrin Ring ◽  
Transfer Processes ◽  
Redox Pair ◽  
Mlct State

A series of meso-phenylpyridylporphyrins and their respective supermolecular species obtained by the coordination of [ Ru ( bipy )2 Cl ]+ groups to the pyridyl substituents was synthesized and characterized. Their spectroscopic and electrochemical behavior were similar to that observed for the meso-tetra(4-pyridyl)porphyrin derivative, but the redox potential of the Ru (III/II) redox pair was about 70 mV more negative. The porphyrin centered fluorescence quantum yield exhibited a linear decrease as a function of the number of pyridyl substituents on the porphyrin ring. Efficient intramolecular energy transfer processes from the 3 MLCT state of the ruthenium complexes to the porphyrin center were observed at 77K in ethanol glass.

Intramolecular energy transfer and photoisomerization in stilbene dendrimers

2017 ◽  
Vol 95 (9) ◽  
pp. 1013-1023 ◽  
Author(s):  
Masahiro Taima ◽  
Yuka Ishida ◽  
Tatsuo Arai
Keyword(s):  
Energy Transfer ◽  
Energy Harvesting ◽  
Photophysical Properties ◽  
Intersystem Crossing ◽  
Intramolecular Energy Transfer ◽  
The Core ◽  
Transfer Processes ◽  
Trans Isomerization ◽  
Photophysical Processes ◽  
In Cis

Stilbene dendrimers with energy harvesting chromophores, such as naphthalene and benzophenone, have been prepared and their photochemical and photophysical properties have been examined. These dendrimers underwent trans–cis mutual photoisomerization on excitation of the core stilbene or the peripheral naphthalene and benzophenone chromophores through several energy transfer processes, and photophysical processes such as intersystem crossing finally resulted in cis-trans isomerization of the core stilbene.

Changes of Excitation Spectra of in vivo Chlorophyll Fluorescence during Induction of Photosynthesis

1993 ◽  
Vol 48 (1-2) ◽  
pp. 46-51 ◽  
Author(s):  
Wieslaw I. Gruszecki ◽  
Zbigniew Krupa
Keyword(s):  
Energy Transfer ◽  
Chlorophyll Fluorescence ◽  
Quantum Yield ◽  
Dark Adaptation ◽  
Fluorescence Quantum Yield ◽  
Excitation Energy Transfer ◽  
Reaction Centers ◽  
Excitation Spectra ◽  
In Vivo Chlorophyll Fluorescence

Excitation spectra of chlorophyll fluorescence from intact rye leaves were registered at different steps of the induction of photosynthesis after dark adaptation. Analysis of these spectra indicates that at least two processes related to spectroscopic features are responsible for a fluorescence quenching. The first one, active during the first 100 s of illumination, was interpreted to consists in an overall decrease of the fluorescence quantum yield of antenna pigments and chlorophylls, in particular close to the reaction centers. The second type of a fluorescence decrease (between 100 s and 300 s of illumination) was found to be in large extent related to decrease of the rate of an excitation energy transfer between accessory xanthophyll pigments and chlorophylls emitting fluorescence. This latter molecular mechanism is discussed as being related to violaxanthin availability to de-epoxidation in the xanthophyll cycle.

Spectral-luminescent effects in heterometallic complexes of crown-porphyrins

2001 ◽  
Vol 05 (05) ◽  
pp. 481-485 ◽  
Author(s):  
YU. KOROVIN ◽  
Z. ZHILINA ◽  
N. RUSAKOVA ◽  
V. KUZ'MIN ◽  
S. VODZINSKY ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Quantum Yield ◽  
Alkali Metal ◽  
Heterometallic Complexes ◽  
Luminescence Spectra ◽  
Intramolecular Energy Transfer ◽  
Triplet Level ◽  
Molecular Luminescence ◽  
Sandwich Type

New complexes of ytterbium with porphyrins containing crown- and other oxygen-containing cyclic substituents were obtained. The absorption, excitation, ligand luminescence and 4f-luminescence spectra have been investigated. It has been shown that 4f-luminescence of ytterbium Yb ( III ) ions was a result of the intramolecular energy transfer from the triplet level of the ligands to the resonance 2F5/2 level of Yb ( III ). It has been also established that in presence of alkali metal Na , K and Cs the dimer complexes (sandwich-type) of ytterbium-crown-porphyrin were formed. Molecular luminescence of the porphyrin matrix was quenched completely in these dimers, but at the same time the quantum yield and lifetime of 4f-luminescence increase in the complexes.

Photophysical properties of microencapsulated phthalocyanines

2010 ◽  
Vol 14 (03) ◽  
pp. 278-283 ◽  
Author(s):  
Virginia E. Diz ◽  
Gabriela A. Gauna ◽  
Cristian A. Strassert ◽  
Josefina Awruch ◽  
Lelia E. Dicelio
Keyword(s):  
Differential Scanning Calorimetry ◽  
Light Scattering ◽  
Quantum Yield ◽  
Fluorescence Quantum Yield ◽  
Photophysical Properties ◽  
Oxygen Production ◽  
Electronic Microscopy ◽  
Scanning Calorimetry ◽  
Singlet Molecular Oxygen ◽  
Photophysical Parameters

Lipophilic substituted zinc(II) phthalocyanines: 2,3,9,10,16,17,23,24-octakis[(N,N-dimethylaminoethylsulfanyl)]phthalocyaninatozinc(II) (S1) and tetrakis(N,N-dibutylaminoethoxy)phthalocyaninatozinc(II) (3) were incorporated into soybean L-α-phosphatidylcholine (SPC) liposomes of 100 nm diameter. Liposomes were characterized by static light scattering (SLS), transmission electronic microscopy (TEM), and differential scanning calorimetry. The fluorescence quantum yield and singlet molecular oxygen production of 3 are Φ F = 0.15 and ΦΔ = 0.24, respectively, whereas the same photophysical parameters for S1 are Φ F = 0.13 and ΦΔ = 0.51. Higher values of Φ F and ΦΔ are obtained in organic solvent for both dyes. Synthesis of compound 3 has also been reported.

Intramolecular Energy Transfer Processes in Binuclear Re−Os Complexes

2001 ◽  
Vol 40 (27) ◽  
pp. 6885-6891 ◽  
Author(s):  
R. Argazzi ◽  
E. Bertolasi ◽  
C. Chiorboli ◽  
C. A. Bignozzi ◽  
M. K. Itokazu ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Intramolecular Energy Transfer ◽  
Transfer Processes

scholarly journals Photophysical Challenges and Antenna Effect Between Click Reaction-based Bodipy Derivatives Manufactured From Knorr Pyrrole

2021 ◽  
Author(s):  
ahmed nuri kursunlu ◽  
Akif Kagan Yilmaz ◽  
Elif Bastug ◽  
Ersin Guler
Keyword(s):  
Energy Transfer ◽  
Quantum Yield ◽  
Absorption Coefficient ◽  
Organic Solvents ◽  
Click Reaction ◽  
Photophysical Properties ◽  
Molar Absorption Coefficient ◽  
Antenna Effect ◽  
Preliminary Study

Abstract In this paper, a series of click reaction-based Bodipy derivatives have been synthesized as part of a preliminary study. Following the characterization of the four challenger molecules, the photophysical properties (absorption, emission, excitation, molar absorption coefficient, quantum yield, etc.) were examined in various organic solvents. The results showed that the energy transfer from the Bodipy cores to other moieties was calculated between 71% and 93% depending on different π-electron configurations and chromophore groups.

scholarly journals Remarkable effect of alkynyl substituents on the fluorescence properties of a BN-phenanthrene

2019 ◽  
Vol 15 ◽  
pp. 1257-1261 ◽  
Author(s):  
Alberto Abengózar ◽  
David Sucunza ◽  
Patricia García-García ◽  
Juan J Vaquero
Keyword(s):  
Quantum Yield ◽  
Fluorescence Quantum Yield ◽  
Triple Bond ◽  
Photophysical Properties ◽  
Parent Compound ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Remarkable Effect ◽  
Cross Coupling Reactions ◽  
Palladium Catalyzed

A series of BN-phenanthrenes with substituents of a diverse nature have been synthesized by palladium-catalyzed cross-coupling reactions of a common chloro-substituted precursor, which was made from readily available materials in only four steps. Evaluation of the photophysical properties of the prepared compounds unveiled an impressive effect of the presence of alkynyl substituents on the fluorescence quantum yield, which improved from 0.01 in the parent compound to up to 0.65 in derivatives containing a triple bond.

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