Generation Of Singlet Oxygen By Decomposition Of Triphenyl Phosphite Ozonide

Chemical Oxygen-iodine Laser(COIL) operates on the collisional energytransfer from singlet oxygen (O₂(a1^â–³)) to iodine atom, and the latter lasing at1.315μm wavelength. So the generation of O₂(a1^â–³) is one of the most criticaltechniques in COIL system. The present method to produce O₂(a1^â–³)is base on thereaction between Cl2 and basic hydrogen peroxide. In recent years, a new way ofgeneration gas-phase O₂(a1^â–³) by decomposition of triphenyl phosphiteozonide(TPPO₃) was proposed in the literature. It has some advantages, including nowater, long store life, inexpensiveness and nontoxicity, but, so far, no experimentalresults have been reported. The main purpose of this paper is to study experimentallythe feasibility of this approach by optimizing the technology and using of catalystto increase O₂(a1^â–³) generation rate , reduce its quench rate and get high O₂(a1^â–³)yield.1. By exploring several different approaches of synthesis of TPPO₃, the bestmethod and reaction conditions are found which turn out a TPPO₃ yield as high as97%, and almost not produce the undesired by-products.2. some methods of generation of O₂(a1^â–³) by spontaneous decomposition of solidTPPO₃ ,thermal decomposition of high concentration TPPO₃ solution on a hightemperature surface and catalyzed decomposition by pyridine have tested. For thefirst time, we observed the cooperative emission at wavelengths 634nm and 703nmof O₂(a1^â–³), which implies decomposition of TPPO₃ may generate highconcentration of gas-phase O₂(a1^â–³) . But in thermal decomposition of TPPO₃, thespectra have a wide-band radiation background other than O₂(a1^â–³) cooperativeemission. Because the energy from unimolecular decomposition of TPPO₃ is notenough for emitting such light, we think it may be emitted by big excited molecularwhich was generated through bimolecular collision under the condition of highTPPO3 concentration. The spectroscopy of catalyzed decomposition of TPPO3 bypyridine demonstrates that it originates definitely from two O2(a1?) molecularcooperative emission. We found that there are a small amount of CO and CO2 in gasproducts of TPPO3 decomposition and a little insoluble in acetone red-brown solidproducts. It shows, other than decomposition of TPPO3 generating O2(a1?) and TPP,there are some other unknown complicated reactions which need to study further.3. In order to understand the TPPO3 decomposition kinetics, we measured its rateconstants at different temperatures in different solvents and obtained thecorresponding activation energy.4. Some experiments were proposed for generation of O2(a1?) by catalyzeddecomposition of TPPO3 in different conditions.