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

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.

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

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.

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

The relative quantum yields of O2(a¹Δg) from the photolysis of ozone in the wavelength range 270nm ≤ λ ≤ 329nm

1993 ◽  
Vol 20 (19) ◽  
pp. 2063-2066 ◽  
Author(s):  
S. M. Ball ◽  
G. Hancock ◽  
I. J. Murphy ◽  
S. P. Rayner
Keyword(s):  
Wavelength Range ◽  
Quantum Yields ◽  
Relative Quantum

scholarly journals Competition Between Cyclization and Unusual Norrish Type I and Type II Nitro-Acyl Migration Pathways in the Photouncaging of 1-Acyl-7-nitroindoline Revealed by Computations

2020 ◽  
Author(s):  
Pierpaolo Morgante ◽  
Charitha Guruge ◽  
Yannick P. Ouedraogo ◽  
Nasri Nesnas ◽  
Roberto Peverati
Keyword(s):  
Density Functional ◽  
Acyl Migration ◽  
Density Functional Theory Calculations ◽  
Computational Procedure ◽  
Quantum Yields ◽  
Type I ◽  
Type Ii ◽  
Relative Quantum ◽  
Norrish Type ◽  
Migration Pathways

The 7-nitroindolinyl family of caging chromophores has received much attention in the past two decades. However, its uncaging mechanism is still not clearly understood. In this study, we performed state-of-the-art density functional theory calculations to unravel the photo-uncaging mechanism in its entirety, and we compared the probabilities of all plausible pathways. We found competition between a classical cyclization and acyl migration pathways, and here we explain the electronic and steric reasons behind such competition. The migration mechanism possesses the characteristics of a combined Norrish Type I and a 1,6-nitro-acyl variation of a Norrish Type II mechanism, which is reported here for the first time. We also introduced a computational procedure that allows the estimation of intersystem crossing rate constants useful to compare the relative quantum yield of substituted cages. This procedure may pave the way for improved cage designs that possess higher quantum yields and a more efficient agonist release.<br>

Dynamics and yields for CHBrCl2photodissociation from 215–265 nm

2016 ◽  
Vol 18 (48) ◽  
pp. 32999-33008 ◽  
Author(s):  
Wyatt G. Merrill ◽  
F. Fleming Crim ◽  
Amanda S. Case
Keyword(s):  
Mass Spectrometry ◽  
Internal Energy ◽  
Multiphoton Ionization ◽  
Energy Partitioning ◽  
Quantum Yields ◽  
Velocity Map Imaging ◽  
Spin Orbit ◽  
Energy Distributions ◽  
Flight Mass Spectrometry ◽  
Relative Quantum

We characterize the energy partitioning and spin–orbit yields for CHBrCl2photodissociation. Resonance enhanced multiphoton ionization selectively detects the Br and Br* product channels. Time of flight mass spectrometry and velocity-map imaging permit measurement of relative quantum yields, as well as kinetic and internal energy distributions. We further interpret the energy partitioning through use of impulsive models.

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