Arrhenius Parameter for Some Gas-phase Cycloaddition Reactions of Singlet Molecular Oxygen

1974 ◽  
Vol 52 (20) ◽  
pp. 3544-3548 ◽  
Author(s):  
R. D. Ashford ◽  
E. A. Ogryzlo
Keyword(s):  
Charge Transfer ◽  
Transition State ◽  
Gas Phase ◽  
Molecular Oxygen ◽  
Rate Constants ◽  
Arrhenius Equation ◽  
Arrhenius Parameter ◽  
Singlet Molecular Oxygen ◽  
Charge Transfer Interaction ◽  
A Charge

Rate constants have been determined for several reactions of O2(1Δg) in the gas phase, at temperatures between 300 and 550 °K. The following values were obtained when the data was fitted to the Arrhenius equation:[Formula: see text]A charge-transfer interaction in the transition-state is invoked to account for the data available for such reactions.

Fluorescence Quenching of Aminodiphenylamines with Chloromethanes

2002 ◽  
Vol 67 (8) ◽  
pp. 1154-1164 ◽  
Author(s):  
Nachiappan Radha ◽  
Meenakshisundaram Swaminathan
Keyword(s):  
Charge Transfer ◽  
Fluorescence Quenching ◽  
Ground State ◽  
Rate Constants ◽  
Quenching Mechanism ◽  
Quenching Rate ◽  
Charge Transfer Interaction ◽  
Electronically Excited ◽  
A Charge

The fluorescence quenching of 2-aminodiphenylamine (2ADPA), 4-aminodiphenylamine (4ADPA) and 4,4'-diaminodiphenylamine (DADPA) with tetrachloromethane, chloroform and dichloromethane have been studied in hexane, dioxane, acetonitrile and methanol as solvents. The quenching rate constants for the process have also been obtained by measuring the lifetimes of the fluorophores. The quenching was found to be dynamic in all cases. For 2ADPA and 4ADPA, the quenching rate constants of CCl4 and CHCl3 depend on the viscosity, whereas in the case of CH2Cl2, kq depends on polarity. The quenching rate constants for DADPA with CCl4 are viscosity-dependent but the quenching with CHCl3 and CH2Cl2 depends on the polarity of the solvents. From the results, the quenching mechanism is explained by the formation of a non-emissive complex involving a charge-transfer interaction between the electronically excited fluorophores and ground-state chloromethanes.

Modulation of the catalytic activity of Pt nanoparticles through charge-transfer interactions with metal–organic frameworks

2017 ◽  
Vol 53 (50) ◽  
pp. 6720-6723 ◽  
Author(s):  
Shotaro Yoshimaru ◽  
Masaaki Sadakiyo ◽  
Aleksandar Staykov ◽  
Kenichi Kato ◽  
Miho Yamauchi
Keyword(s):  
Catalytic Activity ◽  
Charge Transfer ◽  
Co Oxidation ◽  
Oxidation Reaction ◽  
Metal Organic Frameworks ◽  
Pt Nanoparticles ◽  
Charge Transfer Interaction ◽  
Co Oxidation Reaction ◽  
Metal Organic ◽  
A Charge

A charge transfer interaction between Pt nanoparticles and MOFs modulated the catalytic activity of Pt for a CO oxidation reaction.

scholarly journals Compound C2, a product of the reaction of oxygen and the mixed-valence state of cytochrome oxidase. Optical evidence for a type-I copper

1979 ◽  
Vol 177 (3) ◽  
pp. 931-941 ◽  
Author(s):  
B Chance ◽  
C Saronio ◽  
J S Leigh
Keyword(s):  
Charge Transfer ◽  
Cytochrome Oxidase ◽  
Valence State ◽  
Mixed Valence ◽  
Type I ◽  
Blue Copper ◽  
Mixed Valence State ◽  
Charge Transfer Interaction ◽  
A Charge ◽  
Reduced State

Compound C2 is a product of the reaction of O2 and the mixed-valence state of cytochrome oxidase. The mixed-valence state of membrane-bound cytochrome oxidase is obtained at -24 degrees C, by using either ferricyanide or yeast peroxidase complex ES as oxidants, and the configurations of oxidized haem a and its associated copper (a3+Cua2+) and of reduced haem a3 and its associated copper (ac3+.CO.Cua3+) are obtained. The mixed-valence-state cytochrome oxidase mixed with O2 at -24 degrees C and flash-photolysed at -60 to -100 degrees C reacts with O2 and initially forms an oxy compound (A2) similar to that formed from the fully reduced state (A1). Thereafter the course of the reaction differs from that obtained in the fully reduced state, and absorbance increases are observed at 740–750 nm and 609 nm and a decrease at 444 nm, with no increase in absorbance at 655 nm. One possible attribution of the absorbance increases is to charge-transfer interaction between the iron of haem a3 and the copper associated with haem a3, Cua3(2+), having properties of a type-I ‘blue’ copper. A possible attribution of the decrease in absorbance at 444 nm is to liganding of a3(2+). A related explanation is that the 609 nm absorbance involves a charge-transfer interaction of both iron and copper as a mixed-valence binuclear complex, Cua3, having properties of a non-blue copper. Intermediates in addition to Compound C2 are not yet identifiable by chemical or spectroscopic tests. The kinetic and equilibrium properties of Compound C2 are described.

Relative migratory aptitudes in the Schmidt reaction of arylpropanones and 2-arylcyclohexanones

1978 ◽  
Vol 31 (9) ◽  
pp. 1989 ◽  
Author(s):  
RH Prager ◽  
JM Tippett ◽  
AD Ward
Keyword(s):  
Charge Transfer ◽  
Aromatic Ring ◽  
Low Temperatures ◽  
Hydrazoic Acid ◽  
Schmidt Reaction ◽  
Aryl Ring ◽  
Charge Transfer Interaction ◽  
Alkyl Groups ◽  
A Charge ◽  
Electron Donating Groups

The relative migratory aptitude of benzyl and alkyl groups in the reaction of arylpropanones and 2-arylcyclohexanones with hydrazoic acid depends on the solvent, temperature and nature of the substituents in the aryl ring. It is suggested that at low temperatures electron- donating groups in the aromatic ring favour a charge-transfer interaction which affects the relative migratory aptitudes.

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