Fluorescence lifetimes and relative quantum yields of 124-kilodalton oat phytochrome in water and deuterium oxide solutions

Biochemistry ◽  
1987 ◽  
Vol 26 (5) ◽  
pp. 1412-1417 ◽  
Author(s):  
Helmut Brock ◽  
Bela P. Ruzsicska ◽  
Tatsuo Arai ◽  
Wilhelm Schlamann ◽  
Alfred R. Holzwarth ◽  
...  
Keyword(s):  
Deuterium Oxide ◽  
Quantum Yields ◽  
Fluorescence Lifetimes ◽  
Relative Quantum

Electronic spectroscopy of the transition of DCO and lifetimes and relative quantum yields of the state

2011 ◽  
Vol 270 (1) ◽  
pp. 33-39 ◽  
Author(s):  
Steven J. Rowling ◽  
Scott A. Reid ◽  
Klaas Nauta ◽  
Scott H. Kable
Keyword(s):  
Electronic Spectroscopy ◽  
The State ◽  
Quantum Yields ◽  
Relative Quantum

The Mechanism of the HgH A22Π3/2 → X2Σ+ Emission in the Hg(63P0) Photosensitization of Hydrogen and the Alkanes

1973 ◽  
Vol 51 (8) ◽  
pp. 1207-1214 ◽  
Author(s):  
A. C. Vikis ◽  
D. J. Le Roy
Keyword(s):  
Ground State ◽  
Quantum Yields ◽  
Primary Process ◽  
Relative Quantum

The mechanism of the HgH A22Π3/2 → X2Σ+ emission detected in the Hg(63P0) photosensitized decomposition of H2 and some of the lower alkanes, RH, was investigated. It was concluded that ground state HgH was formed in the primary process Hg(63P0) + RH(or H2) → HgH(X2Σ+) + R(or H). The HgH A22Π3/2 → X2Σ+ emission and presumably the A12Π1/2 → X2Σ+ and B2Σ+ → X2Σ+ emission, also observed in the above systems, result from secondary excitation of ground state HgH on collision with Hg(63P0). Studies of the emission made possible the estimation of relative quantum yields for the above primary process.

The photolysis of ozone by ultraviolet radiation. VI. Reactions of O( 1 D)

1972 ◽  
Vol 330 (1580) ◽  
pp. 131-146 ◽  
Keyword(s):  
Quantum Yield ◽  
Oxygen Carrier ◽  
Quantum Yields ◽  
Ozone Decomposition ◽  
Resonance Fluorescence ◽  
Significant Extent ◽  
Molecular Product ◽  
Relative Quantum ◽  
Carrier Gases ◽  
Made In

Tho reactions of O( 1 D) with O 3 , and with O 2 , have been studied by means of two essentially different techniques. Relative quantum yields for ozone decomposition after photolysis by λ = 254 nm radiation were measured by following changes in optical absorption. Relative concentrations of ground state oxygen atoms were measured by means of a resonance fluorescence technique. In both cases, measurements were made in the presence of O 2 , N 2 or He carrier gases in a flow system, at such time after photolysis that reactions involving O( 1 D) and O 2 ( 1 ∑ g + ) had gone to completion, whereas those involving O( 3 P) and O 2 ( 1 Δ g ) had not proceeded to a significant extent. The ‘intermediate’ quantum yields for ozone photolysis in helium and oxygen are 1.9 and 1.6 respectively, referred to an assumed intermediate quantum yield for photolysis in nitrogen of 1.0. In an oxygen carrier, for every ozone molecule decomposed in the primary step there results 1.5 ± 0.1 O( 3 P) atoms. For photolysis in helium this number is approximately 0.6. The results suggest that there are two pathways for the reaction between O( 1 D) and O 3 , in one of which the products are O 2 + 2O: two O atoms are formed on approximately one-third of reactive collisions. There is no evidence for production of an excited molecular product which is reactive on the concentration-time scale of these experiments. It is shown that both the intermediate quantum yield and the [O ( 3 P)] measurements are consistent with the formation of molecular oxygen in the 1 ∑ g + state on 50 to 60% of quenching collisions between O( 1 D) and O 2 .

Molecular Vibrations in the Exciton Theory for Molecular Aggregates. V. Electronic Spectra of Weakly-coupled Systems

1963 ◽  
Vol 16 (3) ◽  
pp. 315 ◽  
Author(s):  
EG McRae
Keyword(s):  
Electronic Spectra ◽  
Fluorescence Spectra ◽  
Vibrational Structure ◽  
Coupled Systems ◽  
Quantum Yields ◽  
Molecular Aggregates ◽  
Relative Quantum ◽  
Electronically Excited ◽  
Anthracene Crystal ◽  
Theoretical Results

The theory of the gross vibrational structure in the electronic spectra of molecular aggregates is developed for the case of weak intermolecular interaction. The electronically excited states are represented by a set of m-m functions corrected to first order as described in Part IV of this series. An explicit treatment is given for aggregates with two molecules per unit cell. Formulae are obtained for the relative vibronic intensities, splittings, and polarization ratios in absorption spectra, and for relative quantum yields and polarization ratios in fluorescence spectra. The theoretical results are compared with those of the E-V coupling theory developed in Parts II and III. On the basis of this comparison, a general equation is put forward to relate the theoretical crystal splitting (i.e. the splitting for a rigid model) to observed polarization ratios in spectra. The theoretical results are compared with the observed vibrational structure in the 3800 Ǻ band system of anthracene crystal. The crystal splitting calculated from the observed polarization ratios is 380 cm-1. The theory accounts, within the rather large experimental error, for the observed variations of polarization ratio in both the absorption and the fluorescence spectra of anthracene crystal.

Relative Quantum Yields for Anaerobic Photoassimilation of Glucose

Nature ◽  
1966 ◽  
Vol 212 (5060) ◽  
pp. 403-404 ◽  
Author(s):  
WOLFGANG WIESSNER
Keyword(s):  
Quantum Yields ◽  
Relative Quantum

Spectral properties and relative quantum yields of new fluorescent stains

1979 ◽  
Vol 2 (1) ◽  
pp. 33-37 ◽  
Author(s):  
Anthony E. Bedrick ◽  
James L. Painter ◽  
Dagmar Lutringer Bonitz
Keyword(s):  
Spectral Properties ◽  
Quantum Yields ◽  
Relative Quantum ◽  
Fluorescent Stains

scholarly journals Spectral properties and photophysical behaviour of water soluble cationic Mg(II) and Al(III) phthalocyanines

2014 ◽  
Vol 12 (3) ◽  
pp. 403-415 ◽  
Author(s):  
Mopelola Idowu ◽  
Yasin Arslanoğlu ◽  
Tebello Nyokong
Keyword(s):  
Aqueous Solution ◽  
Aqueous Medium ◽  
Spectral Properties ◽  
Photophysical Properties ◽  
Strong Dependence ◽  
Water Soluble ◽  
Quantum Yields ◽  
Fluorescence Lifetimes ◽  
High Solubility ◽  
Medium Ph

AbstractPeripherally and non-peripherally tetrasubstituted-[(N-methyl-2-pyridylthio)]phthalocyaninato magnesium (II) (5 and 6) and chloro aluminium (III) (7 and 8) tetraiodide have been synthesized and characterized. The photophysical properties of the complexes in dimethyl sulfoxide (DMSO) and aqueous medium in the presence and absence of cremophore EL have been studied. These complexes show high solubility in aqueous medium though they were aggregated. The triplet state quantum yields (FT) and the triplet lifetimes (tT) were found to be higher in DMSO with ΦT ranging from 0.32 to 0.51, while tT ranged from 282 to 622 ms in DMSO, compared to aqueous medium (pH 7.4 buffer) where ΦT ranged from 0.15 to 0.19 and tT from 26 to 35 ms. Addition of cremophore EL in aqueous solution resulted in partial disaggregation and increased photoactivity. The fluorescence lifetimes of the complexes showed strong dependence on their immediate environment. The ionic magnesium(II) and aluminium(III) phthalocyanines strongly bind to bovine serum albumin (BSA).

The Steady-State and Decay Characteristics of Primary Fluorescence from Live Bacteria

1987 ◽  
Vol 41 (2) ◽  
pp. 234-241 ◽  
Author(s):  
R. A. Dalterio ◽  
W. H. Nelson ◽  
D. Brut ◽  
J. F. Sperry ◽  
J. F. Tanguay ◽  
...  
Keyword(s):  
Steady State ◽  
Pseudomonas Fluorescens ◽  
Emission Spectra ◽  
Fluorescence Decay ◽  
Quantum Yields ◽  
Complex Nature ◽  
Fluorescence Lifetimes ◽  
Excitation Spectra ◽  
Primary Fluorescence ◽  
Rapid Characterization

The intrinsic steady-state fluorescence and fluorescence decay of Staphylococcus epidermidis, Pseudomonas fluorescens, Enterobacter cloacae, Escherichia coli, and Bacillus subtilis have been observed. Excitation spectra were obtained while emission at 430, 455, 487 and 514 nm was being monitored. Emission spectra were obtained with the use of excitation wavelengths of 340, 365, 405, 430 and 460 nm. Fluorescence lifetimes were measured at 430, 487, and 514 nm while selective excitation was caused at 340, 405, and 430 nm. The complex nature of the excitation and emission spectra reflects the presence of a number of different fluorophores. Attempts have been made to describe portions of the bacterial fluorescence in terms of the measured fluorescence properties including lifetimes of molecular components known for their widespread occurrence in bacteria and their relatively high quantum yields. Candidate fluorophores which have been considered include the pteridines, the structurally related flavins, and the pyridine coenzymes. The observation that characteristic sets of lifetimes have been obtained for each organism suggests that measurements of fluorescence lifetimes may be helpful in the rapid characterization of bacteria. Results are especially definitive in cases such as Pseudomonas fluorescens, where one marker fluorophore, a pteridine, is produced in large amounts.

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