A Photocatalytic system combined of low-pressure mercury lamp and heteropoly acid[(CH2)5NH2]3PW12O40 was used for defluorination of aqueous Perfluorooctane sulfonate (PFOS). The effects and mechanism of reaction time, [(CH2)5NH2]3PW12O40 concentration and pH on defluorination were investigated. In addition, the effects and mechanism of improved methods of potential, such as H2O2 and low-frequency ultrasound, were also studied. The results show that photocatalytic system had weak effect on the defluorination of PFOS, while the PFOS could be oxidatively defluorinated with long reaction time. Introduc tion of H2O2 could significantly enhance defluorination of PFOS and low-frequency ultrasound had no obvious effect on defluorination of PFOS in photocatalytic system.

The organic–inorganic hybrid catalyst [(CH2)5NH2]4SiW12O40 was prepared by matrix acid and piperidine. The matrix acid was synthesized by sodium molybdate and sodium silicate, and the piperidine was organic ligand. The proposed composition and structure of the catalyst were evidenced by XPS, FT-IR, XRD, TG-DTA and elemental analysis. The results indicated that the heteropoly anions still reserved their Keggin structure in the compound. Its catalytic performance was evaluated in the oxidation of benzaldehyde to benzoic acid. Various reaction parameters were changed to attain the optimal conditions. The optimal reaction conditions were found to be: n(catalyst): n(benzaldehyde)=3.1×10-3:1; n(H2O2)： n(benzaldehyde)=4.5：1; reaction temperature was 80°C; reaction time was 4h. The yield of benzoic acid achieved above 85%.

The action of the title catalyst with H2O2 leads to a formation of homogeneous phase and an accelerated reaction rate. The catalyst will precipitate in solid particles with the consumption of H2O2 and the decreasing temperature, its recovery is up to 90% and catalytic activity is almost unchanged after six consecutive uses. The effect of reaction conditions on the epoxidation and H2O2 utilization was investigated. Under the conditions of reaction time 2.5h,catalyst 0.3g, stepwise addition of 30%H2O2 3.5（30.88 mmol, reaction temperature 65 ℃,1,2-dichloroethane 20 mL, FAMEs 5.0（22.84 mmol double bond, the product epoxy value is up to 5.78%,double bond epoxidation selectivity 81.9% and H2O2 utilization 86%.

: A retrospective view of exaltation of refraction observed for many unsaturated and aromatic compounds demonstrates that this physical phenomenon is undeservedly considered only as a qualitative measure of conjugation. This mini-review discusses numerous papers by the author that have been published earlier in inaccessible periodicals and collections of scientific papers. Using a great number of illustrations, the author shows that this parameter can be successfully used for quantitative estimate of resonance effects in organic and polymer chemistry. The methods for derivation of strictly additive atomic and group refraction constants are described; these constants were subsequently used as a tool that allowed quantitative estimation of resonance effects in mono-, di-, tri- and polyalkylbenzenes, alkylnaphthalenes, some alkyl derivatives of unsaturated hydrocarbons. These effects cause strictly fixed increase in refraction of carbon atoms in different structural modifications (graphene, fullerene, diamond) and in polycyclic aromatic hydrocarbons. The relevant results regarding quantitative estimation of degree of steric inhibition of resonance in sterically hindered ortho-dialkylbenzenes, 1,2,3- trialkyl-, 1,2,3,4-tetraalkyl-, and 1,2,3,4,5-polyalkylbenzenes accumulated by the author are summarized.