Oxygen, triplet

Reaction with triplet oxygen 0( P) atoms [17778-80-2] gives high yields of CO and chloroacetaldehyde [107-20-0], with smaller amounts of acetyl chloride [75-36-5], HCl, methane [74-82-8], and polymer. The rate of the gas-phase reaction of vinyl chloride with 0( P) atoms has also been reported (41). 

The electrolysis of adamantylideneadamantane solutions affords the radical cation, which can add molecular (triplet) oxygen to give the peroxide radical anion, which can react with adamantylideneadamantane to give the 1,4-diradical and another molecule of adamantylideneadamantane radical cation. The latter reacts with oxygen, to continue the chain of the reaction, while the former cyclizes to the corresponding 1,2-dioxetane (Scheme 18) (81JA2098). 

Singlet oxygen, O2, can readily be generated by irradiating normal triplet oxygen, 2 in the presence of a sensitizer, S, which is usually a fluorescein-type dye, a polycyclic hydrocarbon or other strong absorber of light. A spin-allowed transition then occurs ... 

A different situation arises with a preliminary reduced surface. In this case the measured value of y is within lO - 10 2, and as the temperature increases, the y grows by the Arrhenius Law (Equation) with the activation energy of 5.2 kcal/mole. In addition, there is dependence of y upon the triplet oxygen pressure in the set-up, though the experiment conditions allow us to neglect a priori the impact of homogeneous processes on the spatial distribution of 02( A ) molecules. Prolonged... 

Prolonged seasoning of the adsorbent in triplet oxygen leads to loss of the adsorbent s activity relative to the adsorption of 02( A ). This... 

For the sake of reference let us quote here the constant of reaction rate for triplet oxygen with atom hydrogen [71] 2 + H - + H (2)... 

Fig. 6.18. Temperature dependence of 02 emission (f) and triplet oxygen release (2) during linear heating of VgOn sample in vacuum.

Fig. 6.19. Temperature dependence of triplet oxygen absorption (f) and singlet oxygen emission (2) during the heating of VgOu sample in 0.1 Torr O2.

Reaction of /rart.v-[lr(CO)X(PPh3)2], X = halogen, is 10s—109 times faster with singlet oxygen than with triplet oxygen and yields the same product species (384) in both cases.620... 

Singlet oxygen is more reactive than triplet oxygen toward polyene structures in PVC (95). Also, unlike triplet oxygen, singlet oxygen reacts preferentially with the shorter polyene... 

A detailed mechanism is proposed for this recombination process. On the basis of the experimental results obtained, Beutel (for details see 13>) comes to the conclusion that in the case of dimedone autoxidation the triplet triketone D = O cannot be efficiently quenched by ground-state triplet oxygen formed in the decomposition of a Russell tetroxide which in this case should have the formula. 

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