Critically evaluated rate constants for gaseous reactions of several electronically excited species

1979 ◽  
Vol 8 (3) ◽  
pp. 723-798 ◽  
Author(s):  
Keith Schofield
1972 ◽  
Vol 50 (1) ◽  
pp. 1-7 ◽  
Author(s):  
G. I. Mackay ◽  
R. E. March

Total deactivation rate constants have been determined for N2+(B2Σu+) and the (A2Πu) and (B2Σu+) states of CO2+ with a number of quenchers. The energy specific total deactivation rate constant is compared to the total radiative lifetime of the excited species. A particular novelty of the technique is that it does not require a complete knowledge of the formation modes for the excited species. The results are compared with theoretical values obtained from the ion-induced dipole model. Individual deactivation rate constants are presented for N2+(B2Σu+) ions in the v = 0, 1, and 2 vibrational levels quenched by N2, O2, H2, and CO2; and for the(A2Πu) and (B2Σu+) states of CO2+ quenched byCO2, N2, O2, NO, and H2. Charge transfer is the most probable mode of deactivation except in the CO2+–H2 reactions where H-atom abstraction is more probable.


2002 ◽  
Vol 67 (8) ◽  
pp. 1154-1164 ◽  
Author(s):  
Nachiappan Radha ◽  
Meenakshisundaram Swaminathan

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.


1969 ◽  
Vol 47 (10) ◽  
pp. 1870-1877 ◽  
Author(s):  
F. Stuhl ◽  
K. H. Welge

Rate constants for the collisional deactivation of O(1S) and O2(b1Σg+) are reported. They are obtained by measuring the intensity decay of the O(1S → 1D) and O2(b1Σg+ → X2Σg+) emissions after a pulsed production of the excited species.


1985 ◽  
Vol 82 (9) ◽  
pp. 4073-4075 ◽  
Author(s):  
C. Krier ◽  
M. Th. Praet ◽  
J. C. Lorquet

1966 ◽  
Vol 44 (18) ◽  
pp. 2173-2180 ◽  
Author(s):  
Terumi Terao ◽  
Shun-Ichi Hirokami ◽  
Shin Sato ◽  
R. J. Cvetanović

Experimental evidence is presented for a rapidly occurring intersystem crossing of the electronically excited dideuteroethylene molecules initially formed in the benzene-photosensitized reaction at 2 537 Å and 25 °C to another excited state which is responsible for the internal H-atom scrambling. The mechanism is entirely analogous to that previously postulated for the photoexcited states sensitized by Hg(3P1) atoms but the rate constants for intersystem crossing and molecular decomposition are drastically decreased as a result of the smaller amount of energy available for the excitation.


Nature ◽  
1958 ◽  
Vol 181 (4605) ◽  
pp. 320-321
Author(s):  
J. W. LINNETT

1971 ◽  
Vol 49 (8) ◽  
pp. 1268-1271 ◽  
Author(s):  
G. I. Mackay ◽  
R. E. March

Electron beam excitation of nitrogen was utilized to produce ions in the zeroth and first vibrational levels of the B2Σu+ state. The rate constants for the collisional deactivation of electronically excited N2+, for each of N2 and NO, were determined individually for the v′ = 0 and v′ = 1 vibrational levels of the N2+(B2Σu+) state. Charge transfer is the most probable mode of deactivation.


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