TIME-RESOLVED IR STUDIES OF UV LASER FLASH PHOTOLYSIS OF W(CO)_6 IN C_6H_(12)-CCl_4 AND CCl_4 SOLUTION

Time-resolved IR absorption spectroscopy has been used to atudy the photochemistry of W(CO)_6 in cyclohexane, carbon tetrachloride, and the mixture of carbon tetrachloride and cyelohexane. The reastion of photolytically generated W(CO)_5. C_6H_(12) with CCl_4 was investigated. An intermediate with a lifetime of about 0.5ms, presumably attributed as W(GO)_5.CCl_4, was first observed.

Photophysical Properties and Photoinduced Electron Transfer between [60] Fullerene-Containing Cyclic Sulphoxide [C_(60)-C_6H_8SO] and Tetrathiafulvalene (TTF) by Laser Flash Photolysis

Photoinduced electron transfer (PET) processes between C 60-C 6H 8SO and Tetrathiafulvalene (TTF) have been studied by nanosecond laser photolysis. Quantum yields (Φ et) and rate constants of electron transfer (k et) from TTF to excited triplet state of fullerene-containing cyclic sulphoxide in benzonitrile (BN) have been evaluated by observing the transient absorption bands in the NIR region. With the decay of excited triplet state of fullerene-containing cyclic sulphoxide, the rise of radical anion of fullerene-containing cyclic sulphoxide is observed.

Degradation characteristic of 4-bromdiphenyl ether in mixed solutions by electron beam irradiation

The degradation characteristic of 4-bromdiphenyl ether （BDE-4） was investigated in different solutions.The study indicates that the process of direct degradation of this compound is dependent upon the bromine and the ether bond connected to diphenyl by electron beam.laser flash photolysis was employed to determine the degradation of each species （cationic,neutral,and anionic）.From these data,intermediate products of BDE-4 degradation were shown for direct irradiationdegradation.The neutral radical was formed during the photolysis of these compounds.For all the compounds,diphenyl ether and hydroxybiphenyl were observed as common products.Reaction of the BDE-4 under electron beam was debromide.The debromide rate of BDE-4 at pH=5.5 is somewhat lower than that of BDE-4 at pH=10.0.The decomposition rate for BDE-4 is 99.8% at pH=10.0 on the dose of 14 kGy.BDE-4 from its radical could provide bromine ion into water and the cation radical of BDE-4 formed quickly recombine with hydrogen radical and formed phenyl ether.

Kinetics and mechanisms of reactions for hydrated electron with chlorinated benzenes in aqueous solution

The reactions between chlorinated benzenes （CBzs） and hydrated electron （eaq^-） were investigated by the electron beam （EB） and laser flash photolysis （LFP） experiments. Under the EB irradiation, the effects of irradiation dose, initial concentration and the number of Cl atoms on the removal efficiencies were further examined. At 10 kGy, the removal efficiencies of mono-CB, 1,3-diCB, 1,2-diCB and 1,4-diCB were 41.2%, 87.2%, 84.0%, and 84.1%, respectively. While irradiation dose was 50 kGy, the removal efficiencies increased to 47.4%, 95.8%, 95.0%, and 95.2%, respectively. Irradiation of CBzs solutions has shown that the higher the initial concentration, the lower the percentage of CBzs removal. In addition to this, the dechlorination efficiencies of 1,2-dichlorobenzene （1,2-diCB）, 1,3-dichlorobenzene （1,3-diCB） and 1,4-dichlorobenzene （1,4-diCB） were much higher than that of chlorobenzene （mono-CB）. The kinetics of the reactions was achieved with nanosecond LFP. The rate constants of second-order reaction between eaq^- with mono-CB, 1,2-diCB, 1,3-diCB and 1,4-diCB were （5.3±0.4） × 10^8, （4.76±0.1） × 10^9, （1.01±0.1） × 1010 and （3.29±0.2） × 10^9 L·mol^-1·s^-1, respectively. Density functional theory （DFT） calculations were performed to determine the optical properties of unstable CBzs anion radicals, and the main absorption peaks lied in the range of 300–550 nm. The primary reaction pathway of CBzs with eaq^- was gradual dechlorination, and the major products were Cl^- and benzene （CBzs（-Cl^-））. Furthermore, biphenyl （or chlorobiphenyl） was observed during the LFP, which was probably formed by recombination of benzene radicals.