scholarly journals Photocontrollable Mixed-Valent States in Platinum-Halide Ladder Compounds

2018 ◽  
Vol 8 (11) ◽  
pp. 2126
Author(s):  
Jun Ohara ◽  
Shoji Yamamoto
Keyword(s):  
Electron Transfer ◽  
Light Intensity ◽  
Hubbard Model ◽  
Phase Structure ◽  
Reverse Process ◽  
Phase Arrangement

Employing a two-orbital extended Peierls–Hubbard model, we demonstrate the photomanipulation of mixed-valent states in platinum-halide ladder compounds. There are two types of interchain valence arrangements, namely in-phase and out-of-phase types. The conversion of the in-phase structure to the out-of-phase structure is induced by photoirradiation, which is accelerated with increasing light intensity, while the reverse process hardly occurs. The out-of-phase arrangement is highly stabilized in the photoexcited states by the interchain electron transfer.

scholarly journals Photoinduced 1,2,3,4-tetrahydropyridine ring conversions

2015 ◽  
Vol 11 ◽  
pp. 2166-2170
Author(s):  
Baiba Turovska ◽  
Henning Lund ◽  
Viesturs Lūsis ◽  
Anna Lielpētere ◽  
Edvards Liepiņš ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Solid State ◽  
Light Intensity ◽  
Photoinduced Electron Transfer ◽  
Driving Force ◽  
Spectroscopic Data

Stable heterocyclic hydroperoxide can be easily prepared as a product of fast oxidation of a 1,2,3,4-tetrahydropyridine by 3O2 if the solution is exposed to sunlight. The driving force for the photoinduced electron transfer is calculated from electrochemical and spectroscopic data. The outcome of the reaction depends on the light intensity and the concentration of O2. In the solid state the heterocyclic hydroperoxide is stable; in solution it is involved in further reactions.

Proton- and ion-transfer reactions

1996 ◽  
Author(s):  
Wolfgang Schmickler
Keyword(s):  
Electron Transfer ◽  
Electrode Surface ◽  
Metal Ion ◽  
Metal Electrode ◽  
Transfer Reactions ◽  
Partial Charge ◽  
Reverse Process ◽  
Proton Transfer Reactions ◽  
Solvent Molecules ◽  
Simultaneous Discharge

We consider the transfer of an ion or proton from the solution to the surface of a metal electrode; often this is accompanied by a simultaneous discharge of the transferring particle, such as by a fast electron transfer. The particle on the surface may be an adsorbate as in the reaction: . . .Cl - (sol) ⇋ Clad + e- (metal) . . . (9.1) In this case the discharge can be partial; that is, the adsorbate can carry a partial charge, as discussed in Chapter 4. Alternatively the particle can be incorporated into the electrode as in the deposition of a metal ion on an electrode of the same composition, or in the formation of an alloy. An example of the latter is the formation of an amalgam such as: . . . Zn2++2e- ⇋ Zn(Hg) . . . (9.2) The reverse process is the transfer of a particle from the electrode surface to the solution; often the particle on the surface is uncharged or partially charged, and is ionized during the transfer. Ion- and proton-transfer reactions are almost always preceded or followed by other reaction steps. We first consider only the chargetransfer step itself. Ions and protons are much heavier than electrons. While electrons can easily tunnel through layers of solution 5 to 10 Å thick, protons can tunnel only over short distances, up to about 0.5 Å, and ions do not tunnel at all at room temperature. The transfer of an ion from the solution to a metal surface can be viewed as the breaking up of the solvation cage and subsequent deposition, the reverse process as the jumping of an ion from the surface into a preformed favorable solvent configuration. In simple cases the transfer of an ion obeys a slightly modified form of the Butler-Volmer equation. Consider the transfer of an ion from the solution to the electrode. As the ion approaches the electrode surface, it loses a part of its solvation sphere, and it displaces solvent molecules from the surface; consequently its Gibbs energy increases at first.

Counterion Effects on the Photoinduced Electron-Transfer and the Reverse Process in Porphyrin–Viologen Linked Compounds

1989 ◽  
Vol 18 (8) ◽  
pp. 1445-1448 ◽  
Author(s):  
Akira Mitsui ◽  
Akihiro Uehata ◽  
Hiroshi Nakamura ◽  
Taku Matsuo
Keyword(s):  
Electron Transfer ◽  
Photoinduced Electron Transfer ◽  
Reverse Process

Light Intensity Is a Main Factor Affecting Fresh Market Spinach Tolerance for Phenmedipham

Weed Science ◽  
2016 ◽  
Vol 64 (1) ◽  
pp. 146-153 ◽  
Author(s):  
Ran N. Lati ◽  
Beiquan Mou ◽  
John S. Rachuy ◽  
Steven A. Fennimore
Keyword(s):  
Electron Transfer ◽  
Photosystem Ii ◽  
Light Intensity ◽  
Weed Management ◽  
Short Interval ◽  
Efficient Production ◽  
Light Conditions ◽  
Fresh Market ◽  
Wide Range ◽  
The Impact

The few available herbicides for fresh market spinach do not provide adequate weed control, and there is need for additional herbicide tools. Phenmedipham is registered for use in processing spinach but not in fresh spinach, because of potential injury and the short interval between application and spinach harvest. The objectives of this study were to evaluate the tolerance level of fresh spinach varieties to phenmedipham and evaluate the impact of light intensity on tolerance of spinach to phenmedipham. In the greenhouse, nine spinach varieties were treated with phenmedipham (0.55 kg ai ha−1). Spinach varieties exhibited a wide range of tolerance, and dry weights of treated plants ranged from 40 to 78% compared to the nontreated control. Based on the phenmedipham tolerance screen, two varieties with low (Nordic) and high (Regal) tolerance to phenmedipham were treated, then exposed to half (shaded) and full (nonshaded) sunlight. Nonshaded Nordic treated with phenmedipham had 65% lower dry weight compared to similarly treated plants grown under shade, suggesting that spinach tolerance to phenmedipham was mainly affected by light intensity. Measurements of electron transfer intensity in photosystem II also showed tolerance to phenmedipham that varied among spinach varieties and light intensity. The maximum values of electron transfer in photosystem II of Regal treated with phenmedipham were higher than those of similarly treated Nordic. In the field, phenmedipham was applied under varied light and temperature conditions. The impact of light intensity on yield of treated spinach was greater than the impact of temperature. Phenmedipham applied under high light conditions was more injurious than when applied under low light conditions. Results from this study can contribute to successful integration of phenmedipham into currently used fresh spinach weed management, which in turn can allow more efficient production of this crop.

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