Photolysis of SO2 in the Presence of Foreign Gases. VI. Acetylene and Allene

1974 ◽  
Vol 52 (20) ◽  
pp. 3451-3453 ◽  
Author(s):  
Menachem Luria ◽  
Julian Heicklen

The photolysis of SO2 at 3130 Å and 25 °C in the presence of C2H2 leads to CO, and, in the presence of allene to CO and C2H4 as gas phase products. In the C2H2 system, the CO comes from the two non-emitting triplet states of SO2, 57% from SO2** and 43% from SO2≠. In the allene system, the two excited singlet states of SO2, and possibly the emitting triplet state, also participate. The relative importance of the contributions from each state can be estimated to be >35% from 1SO2, <16% from 3SO2, 8% from SO2*, 12% from SO2**, and 29% from SO2≠.

2009 ◽  
Vol 9 (4-6) ◽  
pp. 289-300
Author(s):  
Carlos Toro ◽  
Alan Hinchliffe ◽  
Federico Arrieta ◽  
Johan Urdaneta ◽  
Yaneth Bermudez ◽  
...  

1972 ◽  
Vol 50 (9) ◽  
pp. 1338-1344 ◽  
Author(s):  
A. W. Jackson ◽  
A. J. Yarwood

Vibrationally excited singlet and triplet states of 2,3-pentanedione are formed by photolysis at 365 nm. The processes removing these excited states in the gas phase are studied by measuring the fluorescence and phosphorescence yields. Fluorescence can occur from the vibrationally excited, as well as the vibrationally equilibrated, singlet state. The fluorescence and phosphorescence data are considered in terms of mechanisms which involve either weak or strong collisions. Although the data cannot distinguish between the alternatives, there are two significant conclusions. The fluorescence data require that emission occur from at least two levels in the singlet manifold. To explain the phosphorescence data, the highest emitting singlet level must not lead to a vibrationally equilibrated triplet state.


2012 ◽  
Vol 1435 ◽  
Author(s):  
Hirotake Kajii ◽  
Hiroki Ohmori ◽  
Yusuke Sato ◽  
Akihiro Katsura ◽  
Yutaka Ohmori

ABSTRACTTo improve the conversion efficiency of polymer photodetectors (PDs) fabricated by solution process, the properties of fluorene-type polymer photodetectors doped with iridium (Ir) and platinum (Pt) complexes were investigated. The devices based on poly(dioctylfluorene) and poly(dioctylfluorene-co-benzothiadiazole) (F8BT) had violet and blue sensitivity, respectively. Triplet materials can enhance the incident-photon-to-current conversion efficiency of the devices utilizing the fluorene-type polymers when their triplet levels are lower than the lowest excited singlet states of the host and higher than the lowest excited triplet states of the host. The transmission of a moving picture was successfully demonstrated using the bilayer F8BT device with green Ir complex as an opto-electrical conversion device. We demonstrate that the polymer PDs fabricated by solution process can be applied to short-range optical communication fields, such as opto-electrical conversion devices for optical links.


A flash photolysis system, using a pulsed laser as source, has been designed and used to study events having a duration of a few nanoseconds; an improvement over conventional flash techniques by a factor of a thousand. The apparatus incorporates both spectrographic and photoelectric monitoring techniques which are easily interchangeable and, apart from the laser itself, it is readily constructed from standard components. Its applications to the observation of the absorption spectra of excited singlet states, short-lived excited triplet states and chemical events in the nanosecond time region are described.


1987 ◽  
Vol 109 ◽  
Author(s):  
Paul Tavan ◽  
Klaus Schulten

ABSTRACTWe apply the Pariser-Parr-Pople Hamiltonian to study many-electron excitations in polyenes and polyacetylene. The excited singlet states of polyenes, calculated by a multireference double excitation expansion, are classified as quasi-particle excitations, namely as triplet-triplet magnons and particle-hole excitons. From finite polyene spectra we derive approximate dispersion relations for these quasi-particles in the infinite polyene, i.e. polyacetylene.


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