Photolysis data

The broad behavior of the anisotropy parameter versus speed curves is similar for all photolysis wavelengths. Unfortunately the 266 nm photolysis data at high 0(3P2) speeds was of insufficient quality to fit anisotropy parameters satisfactorily, so we cannot state with confidence whether the speed dependence of (3 changes at higher photolysis wavelengths. The overriding feature in Fig. 15 is the steady increase in [3 as the 0(3P2) fragments travel faster. Some structure is also apparent in the curves, with a plateau between approximately 1200 and 3700 m/s. 

In this section are more detailed discussions about soil sorption, volatility, soil core data and photolysis data and how they bear on leaching potential. 

Calculation of k 3 and k2 from the flash photolysis data requires the extinction coefficient of RhCl(PPh3)2 at in order... 

The results of irradiating the pora-quinoid structures (compounds 1-4) absorbed onto cellulose sheets are summarized in Figure 2. Examination of the photolysis data indicates that with the notable exception of 2-methoxy-l,4-benzoquinone the remainingpara-quinone model compounds did not cause any further darkening of the handsheets during irradiation. Indeed, several of the quinones exhibit a minor brightening response upon photolysis which could be attributed to a photo-bleaching effect, but the lack of a complete mass balance makes this conclusion tenuous. 

Based on this mechanism, the distinctions observed between the T-T absorption spectra of the intermediate product and nonphotochromic para-naphthacene-quinone51 with a similar structure were explained by the T-T absorption of the photoinduced ana form of this compound, which is observed after the excitation of a photochromic solution by the laser pulse with a width of 25 ns. However, according to other laser photolysis data for compounds of this type, the intermediate product is a a -spirocomplex,60 which was assumed earlier.5,51... 

Photolysis aqueous photolysis = 1900-19000 h, based on experimental photolysis data utilizing an artificial light source (Draper Crosby 1983 quoted, Howard et al. 1991) ... 

The photolysis data obtained for the [Co (sep)] +...Br" ion pair on light excitation indicate that a photochemical reaction is not detected in deoxygenated aqueous solutions < 10 ). Unlike the [Co(sep)] +...r system, the photochemical reaction for the... 

The use of Co + ions as a radical trap and the flash photolysis data obtained for such a system [381] indicate that during the oxidation of [Co(sep)]2+ cation the superoxide radical O2 anion is formed as an intermediate and its reduction even in acidic media (Reaction 137) is more favourable than disproportionation (Reaction 138). 

Photoreductiom in Aqueous Solution. Solvated electrons form on the irradiation of natural water samples or of aqueous solutions of natural organic matter isolated from surface waters (12, 45, 46). The solvated electron is a powerful reductant that reacts rapidly with electronegative substances such as chlorinated, brominated, and iodinated compounds. The interaction of pho-toejected electrons and a halocarbon is demonstrated by the laser flash photolysis data shown in Figure 3. 

The photolysis data provide important information relative to the modes of decomposition of excited ethyl chloride molecules. The fact that the photolysis yields show a larger excess of ethylene-acetylene... 

The photolysis data indicate the product ratio, 2,3-C4H8Cl2/l,3-C4H8C12 = 3.2. Since all of the chlorobutane products (including 2-C4H9Cl), are formed by appropriate combinations of H3C—CH—Cl and H2C—CH2—Cl radicals, it can be deduced from this ratio, ignoring possible differences in steric factors, that abstraction of a H atom from the a-carbon of ethyl chloride is 7.4 times more probable than abstraction from the /2-carbon. This comparatively low concentration of the -radical accounts for the failure to observe 1,4-dichlorobutane as a product in these experiments since its concentration would be (1/7.4)2 times the 2,3-dichlorobutane concentration and therefore too small to be observed by our analytical methods. The small quantity of 1-chlorobutane observed as a photolysis product can be explained similarly since it would also involve the /2-chloroethyl radical. 

The efficiencies of Br and Br2 were determined [104] over the temperature interval 300—2985°K by combining the flash photolysis data... 

PROBABLE FATE photolysis, data not available oxidation oxidation by peroxy radicals or singlet oxygen is not expected to be important hydrolysis aquatic hydrolysis is not expected to be significant volatilization volatilization is not expected to be significant or important sorption if released to water, adsorption to sediments appears to be the important fate process biological processes bioconcentration is expected to be an important fate process if released to water... 

PROBABLE FATE photolysis, data inconclusive, photolysis is probably greatly hindered by strong adsorption, atmospheric and aqueous photolytic half-life 3-25 hrs oxidation-. chlorine and/or ozone in sufficient quantities may oxidize phenanthrene, photooxidation half-life in air 2.01-20.1 hrs hydrolysis-, not important volatilization probably not an important transport process sorption probably the dominant transport process, organic particulates preferred biological processes short-term bioaccumulation, metabolization and biodegradation are the principal fates... 

The models proposed to explain photolysis data have generally invoked the presence of lattice distortion. Dislocations could, for instance, serve as reaction sites, or generate vacancies, or trap electrons, etc. However, there is only indirect experimental evidence for the role played by defects. 

Table I. Aqueous Concentrations and Photolysis Data for Indoles and Carbazole In Aqueous CRH-1...

Correlation coefficients were calculated from photolysis data at times t. t Q, and t Q min. 

Similar treatments of the additional photolysis data for all the investigated PCDDs were carried out. 

Figure 1. First-order treatment of the photolysis data for...

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