High-Energy Charge-Separated States by Reductive Electron Transfer Followed by Electron Shift in the Tetraphenylethylene–Aluminum(III) Porphyrin–Fullerene Triad

2018 ◽  
Vol 123 (1) ◽  
pp. 131-143 ◽  
Author(s):  
Niloofar Zarrabi ◽  
Christian Agatemor ◽  
Gary N. Lim ◽  
Adam J. Matula ◽  
Brandon J. Bayard ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Energy Charge ◽  
High Energy

New development of photoinduced electron-transfer catalytic systems

2007 ◽  
Vol 79 (6) ◽  
pp. 981-991 ◽  
Author(s):  
Shunichi Fukuzumi
Keyword(s):  
Electron Transfer ◽  
Organic Solar Cells ◽  
Charge Separation ◽  
Energy Charge ◽  
High Energy ◽  
Significant Loss ◽  
Catalytic Systems ◽  
Molecular Electron ◽  
New Development ◽  
Donor Acceptor

As an alternative to conventional charge-separation functional molecular models based on multi-step long-range electron transfer (ET) within redox cascades, simple donor-acceptor dyads have been developed to attain a long-lived and high-energy charge-separated (CS) state without significant loss of excitation energy. In particular, a simple molecular electron donor-acceptor dyad, 9-mesityl-10-methylacridinium ion (Acr+-Mes), is capable of fast charge separation but extremely slow charge recombination. Such a simple molecular dyad has significant advantages with regard to synthetic feasibility, providing a variety of applications for photoinduced ET catalytic systems, including efficient photocatalytic systems for the solar energy conversion and construction of organic solar cells.

scholarly journals Interfacing High‐Energy Charge‐Transfer States to a Near‐IR Sensitizer for Efficient Electron Transfer upon Near‐IR Irradiation

2020 ◽  
Vol 59 (52) ◽  
pp. 23697-23705
Author(s):  
Dilip Pinjari ◽  
Ajyal Z. Alsaleh ◽  
Yuvraj Patil ◽  
Rajneesh Misra ◽  
Francis D'Souza
Keyword(s):  
Electron Transfer ◽  
Charge Transfer ◽  
Energy Charge ◽  
High Energy ◽  
Near Ir

scholarly journals Titelbild: Interfacing High‐Energy Charge‐Transfer States to a Near‐IR Sensitizer for Efficient Electron Transfer upon Near‐IR Irradiation (Angew. Chem. 52/2020)

2020 ◽  
Vol 132 (52) ◽  
pp. 23549-23549
Author(s):  
Dilip Pinjari ◽  
Ajyal Z. Alsaleh ◽  
Yuvraj Patil ◽  
Rajneesh Misra ◽  
Francis D'Souza
Keyword(s):  
Electron Transfer ◽  
Charge Transfer ◽  
Energy Charge ◽  
High Energy ◽  
Near Ir

Interfacing High‐Energy Charge‐Transfer States to a Near‐IR Sensitizer for Efficient Electron Transfer upon Near‐IR Irradiation

2020 ◽  
Vol 132 (52) ◽  
pp. 23905-23913
Author(s):  
Dilip Pinjari ◽  
Ajyal Z. Alsaleh ◽  
Yuvraj Patil ◽  
Rajneesh Misra ◽  
Francis D'Souza
Keyword(s):  
Electron Transfer ◽  
Charge Transfer ◽  
Energy Charge ◽  
High Energy ◽  
Near Ir

Temperature and the Regulation of Enzyme Activity in the Hibernator. Isoenzymes of Liver Pyruvate Kinase from the Hibernating and Non-hibernating Arctic Ground Squirrel

1974 ◽  
Vol 52 (10) ◽  
pp. 894-902 ◽  
Author(s):  
Hans W. Behrisch
Keyword(s):  
Molecular Weight ◽  
Pyruvate Kinase ◽  
Wide Temperature Range ◽  
Ground Squirrel ◽  
Energy Charge ◽  
High Energy ◽  
Ground Squirrels ◽  
The Arctic ◽  
Arctic Ground Squirrel ◽  
Temperature Range

Liver of the hibernating (H) Arctic ground squirrel (Citellus undulatus) contains a single species of pyruvate kinase (PyK) that is distinct from the single isoenzyme of pyK observed in the non-hibernating (NH) ground squirrel, which has been previously described (Behrisch &Johnson (1974) Can. J. Biochem. 52, 547–559). The H-PyK has a pI value of 5.7 and a molecular weight of 241 000 – 243 000. Affinity of the H-PyK for the substrates phosphoenolpyruvate (PEP) and ADP is not affected by changing temperature. It is argued that this stability of the apparent Km's for substrate over a wide temperature range permits the hibernator to take advantage of the Q10 effect in maintaining a low rate of the PyK reaction. Similarly, affinity of H-PyK for the allosteric activator fructose-1,6-phosphate (FDP) and the inhibitor ATP is also conspicuously independent of temperature, suggesting a fine stoichiometry in the relative concentrations of the regulatory ligands in control of H-PyK over a wide temperature range. Further, affinity of H-PyK for the inhibitor ATP is about three- to fourfold lower than that of the NH-PyK, a condition that would favor the maintenance of a high energy charge in the hibernating liver cell. ATP apparently inhibits PyK by causing a dissociation of the enzyme molecule into two "halves" of about 110 000 molecular weight each. This dissociation is offset and reversed by FDP. Removal of the ATP by dialysis does not of itself result in a reassociation of the PyK "halves"; FDP and/or the substrates are required for the two subunits of PyK to reassociate. As the apparent Ki of H-PyK for ATP is higher than that of NH-PyK, substantially higher concentrations of ATP are required to effect the dissociation of H-PyK. Similarly, elevated concentrations of FDP are required to offset the ATP-caused dissociation of the H-PyK.Hibernating Arctic ground squirrels that are preparing to emerge finally from the hibernating state already possess substantial activities of the NH-PyK isoenzyme. This suggests that the animal "anticipates" its transition from one metabolic state from another. On the basis of these data a formal mechanism is proposed for the regulation of liver PyK in the Arctic ground squirrel in both the non-hibernating and hibernating states.

Lorentz-Pole Model and Polarization in High-Energy Charge-Exchange Pion-Nucleon Scattering

1968 ◽  
Vol 175 (5) ◽  
pp. 1757-1761 ◽  
Author(s):  
N. G. Antoniou ◽  
S. R. Komy ◽  
C. D. Palev ◽  
M. Samiullah
Keyword(s):  
Charge Exchange ◽  
Energy Charge ◽  
High Energy ◽  
Pole Model ◽  
Nucleon Scattering ◽  
Pion Nucleon

Kinetics of Electron Transfer Reaction between Co(II) and Chlorate Ions: Experimental and Modeling Study

2021 ◽  
Vol 43 (5) ◽  
pp. 559-559
Author(s):  
Mahwish Mobeen Khan and Syed Mumtaz Danish Naqvi Mahwish Mobeen Khan and Syed Mumtaz Danish Naqvi
Keyword(s):  
Electron Transfer ◽  
Transfer Reaction ◽  
High Energy ◽  
Electron Transfer Reaction ◽  
Maximum Likelihood Estimates ◽  
Oxidation Catalyst ◽  
Standard Entropy ◽  
Rate Of Reaction ◽  
Kinetics Of ◽  
Activated Complex

This research article reports original experimental and modeling detail of kinetics of the electron transfer reaction between Co(II) and chlorate ions in acetic acid solution. Design of experiment methodology has been employed to elucidate the effects of temperature and initial concentrations of reactants on the rate of reaction. Levenberg-Marquardt method has been used to fit processed kinetic data (temperatures, initial concentrations of reactants, and concentrations and rates of production of Co(III)) on to various possible rate equations. This algorithm provides a proficient mean for compensating the capricious effects of the experimental process variables and results in the maximum likelihood estimates of the kinetic parameters. The most significant rate law has been selected, on the basis of statistical analyses of the residuals between the predicted and experimental rates. The analyses suggest that the intrinsic rate of reaction is proportional to first power of chlorate concentration but for Co(II) the order is fractional (0.7455 ≈ and#190;). The effect of temperature on the observed rate constant (precision = 0.02 %) is excellently described by the Arrhenius and Eyring equations and the sluggish nature of the reaction is clearly manifested by the high energy (andgt; 93 kJ/mol), negative entropy (-28.5286 J/mol-K) and very small equilibrium constant of activation. Further fairly negative standard entropy of activation shows there is usually considerable rearrangement of energy among various degrees of freedom during the formation of activated complex and proposes an associative mechanism for formation of the activated complex. This research is performed to develop a kinetic model for the electron transfer reaction between Co(II) and chlorate ion. As a result, a redox couple of Co(II)/Co(III) has been formed which is used as a potent oxidation catalyst in chemical industries.

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