Performance test of a rapid “multiwavelength flash photolysis apparatus≓

1981 ◽  
Vol 7 (4) ◽  
pp. 327-327
Author(s):  
Rainer Uhl ◽  
Birgit Meyer
Keyword(s):  
Performance Test ◽  
Flash Photolysis ◽  
Photolysis Apparatus

Design of a flash photolysis apparatus

1971 ◽  
Vol 4 (6) ◽  
pp. 417-420 ◽  
Author(s):  
M Vallotton ◽  
U P Wild
Keyword(s):  
Flash Photolysis ◽  
Photolysis Apparatus

A versatile flash photolysis apparatus

1992 ◽  
Vol 63 (3) ◽  
pp. 2069-2072 ◽  
Author(s):  
Charles J. Beischel ◽  
Stacie K. Moore ◽  
Rosalie K. Crouch ◽  
Daniel R. Knapp
Keyword(s):  
Flash Photolysis ◽  
Photolysis Apparatus

Picosecond flash photolysis apparatus with high absorbance resolution

1988 ◽  
Vol 59 (8) ◽  
pp. 1307-1309 ◽  
Author(s):  
Thomas W. Ebbesen
Keyword(s):  
Flash Photolysis ◽  
Photolysis Apparatus

THE ABSORPTION SPECTRUM OF THE Si2 MOLECULE

1963 ◽  
Vol 41 (1) ◽  
pp. 152-160 ◽  
Author(s):  
R. D. Verma ◽  
P. A. Warsop
Keyword(s):  
Absorption Spectrum ◽  
Dissociation Energy ◽  
Ground State ◽  
Flash Photolysis ◽  
Lower State ◽  
The Third ◽  
Photolysis Apparatus ◽  
Vibrational Constants

Three band systems of Si2 have been found in absorption with a flash photolysis apparatus. Two of the band systems at 3200 and 2100 Å are new, whereas the third is an extension of the 3Σ–3Σ system observed by Douglas in emission. All three systems have the same lower state and arise from [Formula: see text] transitions. It is very probable that the [Formula: see text] state is the ground state of the Si0 molecule. Rotational and vibrational constants of all four 3Σ states have been determined. The dissociation energy of Si2 is estimated to be 3.0 ± 0.2 ev.

An inexpensive flash photolysis apparatus and demonstration experiment

1974 ◽  
Vol 51 (5) ◽  
pp. 354 ◽  
Author(s):  
K. W. Chambers ◽  
I. M. Smith
Keyword(s):  
Flash Photolysis ◽  
Demonstration Experiment ◽  
Photolysis Apparatus

Studies of triplet chlorophyll by microbeam flash photolysis

1966 ◽  
Vol 295 (1440) ◽  
pp. 1-12 ◽  
Keyword(s):  
Half Life ◽  
Room Temperature ◽  
Flash Photolysis ◽  
Singlet State ◽  
Excited Singlet State ◽  
Intermolecular Distance ◽  
Plant Leaves ◽  
Excited Singlet ◽  
Cationic Detergent ◽  
Photolysis Apparatus

A microbeam flash photolysis apparatus has been developed for use with samples 50 to 250 μ m square, and from 5 to several hundred microns thick. Triplets of chlorophyll a and b were observed in a number of solid solvents, including cholesterol, at room temperature without prior outgassing. In cholesterol the triplet yield decreased with increasing concentration according to the Stern-Volmer law, but the half life of the chlorophyll b triplet was 3 ± 0.2 ms, and independent of concentration. Therefore, the excited singlet state but not the triplet is quenched by a concentration-dependent process. The half-quenching concentration of 2 x 10 -3 M, corresponding to a mean intermolecular distance of 95 Å, points to quenching by inductive resonance. No triplets of chlorophyll appeared on flashing normal or etiolated plant leaves. Leaves treated with cationic detergent gave triplets in a yield of 15%, and exhibited increased fluorescence.

THE FLASH PHOTOLYSIS OF DIACETYLENE

1957 ◽  
Vol 35 (2) ◽  
pp. 129-133 ◽  
Author(s):  
J. H. Callomon ◽  
D. A. Ramsay
Keyword(s):  
Photochemical Reaction ◽  
Flash Photolysis ◽  
Rotational Temperature ◽  
Thermal Reaction ◽  
Time Interval ◽  
Transient Species ◽  
Flash Tube ◽  
Photolysis Apparatus ◽  
Considerable Excess ◽  
Photochemical Decomposition

A brief description is given of a "microsecond" flash photolysis apparatus in which a 40 µf. condenser charged to 8000 v. is discharged through a photolysis flash tube in ~20 microseconds. Absorption spectra of transient species are photographed with a second flash tube which provides a source of continuum by discharging a 2 µf. condenser charged to 10,000 v., in 3–5 microseconds. A circuit for controlling the time interval between the two flashes is given.Experiments on the flash photolysis of diacetylene are discussed. With diacetylene at 0.5 mm. Hg pressure several well-known band systems were photographed in absorption 20 microseconds after the beginning of the photolysis flash, viz., the C2 Swan bands, the C2 Phillips bands, the C2 Deslandres–d'Azambuja bands, the 4050 Å bands of C3, and the CH band at 3143 Å. The rotational temperature of these bands was ~3000°–5000° K. The C2 Swan bands were also recorded in emission after a single photolysis flash. When a considerable excess (100:1) of helium was added to the diacetylene, all the above band systems disappeared with the exception of the C3 bands.In the absence of helium it is probable that the reaction is mainly thermal and that the high temperature is produced by a thermal explosion of the diacetylene triggered by the photolysis flash. The thermal reaction is suppressed by the addition of excess helium and the photochemical reaction becomes dominant. Under these conditions it is interesting to note that C3, but no C2, is produced. It appears therefore that C3 is a product of the photochemical decomposition of diacetylene. Possible mechanisms are discussed.

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