Comparative studies of ozonation alone, ceramic honeycomb-catalyzed and Mn-Fe-K modified ceramic honeycomb catalyzed ozonation processes have been undertaken with benzophenone as the model organic pollutant. The exper...Comparative studies of ozonation alone, ceramic honeycomb-catalyzed and Mn-Fe-K modified ceramic honeycomb catalyzed ozonation processes have been undertaken with benzophenone as the model organic pollutant. The experimental results showed that the presence of Mn-Fe-K modified ceramic honeycombs significantly increased the removal rate of benzophenone and TOC compared with that achieved by ozonation alone or ceramic honeycomb-catalyzed ozonation. The electron paramagnetic resonance (EPR) experiments verified that higher benzophenone removal rate was attribute to more hydroxyl radicals generated in the Mn-Fe-K modified ceramic honeycomb-catalyzed ozonation. Under the conditions of this experiment, the degradation rate of all the three ozonation processes are increasing with the amount of catalyst, temperature and value of pH increased in the solution. We also investigated the effects of different process of ozone addition, the optimum conditions for preparing catalyst and influence of the Mn-Fe-K modified ceramic honeycomb after multiple-repeated use.展开更多
A benzophenone derivative photoinitiator, HBP-TDI-HQ-TDI-HBP (HTCTH), was synthesized based on 4-hydroxy benzophenone (HBP), toluene-2,4-diisocyanate (TDI) and hydroquinone (HQ). HTCTH was a more effective pho...A benzophenone derivative photoinitiator, HBP-TDI-HQ-TDI-HBP (HTCTH), was synthesized based on 4-hydroxy benzophenone (HBP), toluene-2,4-diisocyanate (TDI) and hydroquinone (HQ). HTCTH was a more effective photoinitiator which had longer wavelength absorption in the UV-vis absorption spectra than the low molecular counterpart benzophenone (BP). It showed that both rate of polymerization (Rp) and final conversion (P) increased with increase of amine and HTCTH concentration in photopolymerization.展开更多
A new benzophenone, securiphenone A was isolated from the roots of Securidaca inappendiculata. Its structure was. determined as 2, 3-methylenedioxy-4-methoxybenzophenone by spectroscopie methods.
Dodecyl-benzophenone(DBP) and hexadecoxyl-benzophenone(HDBP) as type 11 photoinitiators used for radical photopolymerization systems were synthesized by Friedel-Crafts reaction, and characterized by 1H NMR and FTI...Dodecyl-benzophenone(DBP) and hexadecoxyl-benzophenone(HDBP) as type 11 photoinitiators used for radical photopolymerization systems were synthesized by Friedel-Crafts reaction, and characterized by 1H NMR and FTIR spectroscopy. The UV-Vis absorption spectra of DBP and HDBP, propitious to photopolymerization under a commercial mercury UV bulb are centered at 345 and 335 nm, respectively. HDBP has higher extinction coefficient than DBP, but lower photoinitiating efficiency. Their photoinitiating performances for EB605, a bisphenol A epoxy acrylate with 40%(mass fraction) tripropyleneglycol diacrylate (TPGDA), resin consisting of bisphenol A epoxy acrylate and tripropyleneglycol diacrylate in the presence of triethanolamine as a coinitiator were investigated by photo-differential scanning calorimetry(photo-DSC). DBP initiates the curing of acrylate more efficiently than HDBP, showing higher photopolymerization rate and unsaturation conversion, resulted from the poor compatibility of HDBP with the resin. The photoinitiating activity of DBP to epoxy acrylate resin is even higher than that of BP at lower loadings.展开更多
The effects of magnetic field on the graft ratio and stereoregularity of grafts of PVA-g-MMA in the presence ofbenzophenone during UV irradiation are discussed. By means of IR, it was found that the graft ratio was in...The effects of magnetic field on the graft ratio and stereoregularity of grafts of PVA-g-MMA in the presence ofbenzophenone during UV irradiation are discussed. By means of IR, it was found that the graft ratio was increased with the increment of magnetic field strength. Furthermore, application of relative weak magnetic field of 0.4 Tesla had been shown to substantially enhance the stereo-regularity of graft copolymer. The maximum stereo-regularity appeared when the graft ratio approached to 85% with the magnetic field of 1.2 Tesla (T). The resistance to moisture and heat resistance of the grafted copolymer in the presence of magnetic field were also improved.展开更多
The radical intermediates, the crosslink microstructures, and the reaction mechanism of benzophenone (BP)-photoinitiated crosslinking of low-density polyethylene (LDPE) and model compounds (MD) have been reviewed in d...The radical intermediates, the crosslink microstructures, and the reaction mechanism of benzophenone (BP)-photoinitiated crosslinking of low-density polyethylene (LDPE) and model compounds (MD) have been reviewed in detail. The spin-trapping electron spin resonance (ESR) spectra obtained from the LDPE/BP systems with spin-trap agents show that two kinds of polymer radical intermediates are mainly formed: tertiary carbon and secondary carbon radicals. The spin-trapping ESR studies of MD/BP systems give further evidence that photocrosslinking reactions of PE predominantly take place a sites of tertiary carbon, secondary carbon, and especially allylic carbon when available. The high resolution C-13-NMR spectra obtained from LDPE and MD systems show that the crosslink microstructures have H- and Y-type links and that their concentrations are of the same order. The fluorescence, ESR, C-13 and H-1-NMR spectra from the PE and MD systems demonstrate that the main photoreduction product of BP (PPB) is benzpinacol formed by the recombination of two diphenylhydroxymethyl (K-.) radical intermediates. Two new PPB products: an isomer of benzpinacol with quinoid structure, 1-phenylhydroxymethylene-4-diphenylhydroxymethyl-2,5-cyclobexadiene and three kinds of alpha-alkyl-benzhydrols have been detected and identified. These results provide new experimental evidence for elucidating the reaction mechanism in the BP-photoinitiated crosslinking of polyethylene.展开更多
New two-photon absorption dyes including benzophenone parts, p-N,N-diphenylamino-p'-phenacylstilbene (C1), 4,4-di-(4- benzoylstyrene)yltriphenylamine (C2) and 4,4',4'-tri(4-benzoylstyrene)yltriphenylamine ...New two-photon absorption dyes including benzophenone parts, p-N,N-diphenylamino-p'-phenacylstilbene (C1), 4,4-di-(4- benzoylstyrene)yltriphenylamine (C2) and 4,4',4'-tri(4-benzoylstyrene)yltriphenylamine (C3), were synthesized and characterized by ^1H NMR and elemental analysis. The ratio of the molar extinction coefficients of compounds was approximately equal to the ratio of the branch amount of the compounds, namely, C1:C2:C3 was 1:2:3. Extremely high fluorescence quantum yields were detected for these compounds. These molecules exhibited obvious two-photon upconcerted fluorescence as excited by 800 nm Ti:sapphire femtosecond laser.展开更多
A novel binary photosensitization system composed of benzophenone (BP)/diphenyliodonium chloride (DPIOC) Ariethylamine (TEA), exhibiting a good photoresponse at near UV and visible light regions, was used as the initi...A novel binary photosensitization system composed of benzophenone (BP)/diphenyliodonium chloride (DPIOC) Ariethylamine (TEA), exhibiting a good photoresponse at near UV and visible light regions, was used as the initiator for photopolymerization of MMA. The radical photogeneration in the binary system consists mainly of two parallel reactions, i. e. , BP/TEA photohydrogen-abstraction and DPIOC/TEA complex photodecomposition, but the latter is more active than the former. The results of comparative study indicate that the rate of polymerization induced by the binary system (BDT)is remarkably higher than those by the corresponding single systems The polymerization rates are proportional to [BP]^(0.16), [DPIOC]^(0.32) [TEA]^(0.45) and [MMA]. The mechanism is also discussed.展开更多
In the process of bulk photopolymerization of styrene initiated by AIBN decomposition polyvinyl benzophenone (PVB) can supply an effective cage for triplet-triplet energy transfer between PVB macromolecules and small ...In the process of bulk photopolymerization of styrene initiated by AIBN decomposition polyvinyl benzophenone (PVB) can supply an effective cage for triplet-triplet energy transfer between PVB macromolecules and small molecules of AIBN to influence the molecular weight of polystyrene in weak magnetic field (less than 0.035T), that was different from the case of polyvinyl naphthalene (PVN) which supplied cages for this system only in the stronger magnetic field (more than 0.2 T) studies. It was found that in the same conditions, PVN could exert more tremendous influences on the bulk photopolymerizatiou system of styrene than PVB because in the stronger magnetic field the triplet PVN had much longer life time than PVB.展开更多
Photoinduced charge transfer reaction of benzophenone(BP) with, mine was carried out in the vesicles of dicetyldimethylammonium bromide (DCDAB) over wide ranges of amine concentration (0. 01~4. 0M). Linear plots of ...Photoinduced charge transfer reaction of benzophenone(BP) with, mine was carried out in the vesicles of dicetyldimethylammonium bromide (DCDAB) over wide ranges of amine concentration (0. 01~4. 0M). Linear plots of φ^(-1) vs. [TEA]^(-1) at low concentration of amine (<0.02M) and Φ^(-1) vs. [TEA]^(-2) at high concentration were obtained. Kinetic data demonstrate that the electron transfer is promoted significantly by DCDAB vesicles and proton transfer becomes more efficient at high Rmlne concentrations, leading to a decrease of Kd/Kr and increase of Kh/Ke. The kinetic expressions of photoreaction of BP bound to DCDAB bilayer are developed.展开更多
The brominated products, formed in chlorination treatment of benzophenone-4 in the presence of bromide ions, were identified, and the formation pathways were proposed.Under disinfection conditions, benzophenone-4 woul...The brominated products, formed in chlorination treatment of benzophenone-4 in the presence of bromide ions, were identified, and the formation pathways were proposed.Under disinfection conditions, benzophenone-4 would undertake electrophilic substitution generating mono- or di-halogenated products, which would be oxidized to esters and further hydrolyzed to phenol derivatives. The generated catechol intermediate would be transformed into furan-like heterocyclic product. The product species were p H-dependent,while benzophenone-4 elimination was chlorine dose-dependent. When the chlorination treatment was performed on ambient water spiked with benzophenone-4 and bromide ions, most of brominated byproducts could be detected, and the acute toxicity significantly increased as well.展开更多
The chemically induced dynamic electron polarization (CIDEP) of photolyzed benzophenone radicals in the microheterogeneous phase systems has been made by using the time-resolved electron spin resonance (TRESR) spe...The chemically induced dynamic electron polarization (CIDEP) of photolyzed benzophenone radicals in the microheterogeneous phase systems has been made by using the time-resolved electron spin resonance (TRESR) spectrometer. In the AEO<sub>9</sub>/isoproanol/H<sub>2</sub>O/C<sub>8</sub>H<sub>18</sub> liquid crystal system, the TRESR spectrum of Ph<sub>2</sub>COH shows an unusual CIDEP of spin correlation radical pair (SCRP). The SCRP formation in these systems resulting from the character microenvironment and the related physical-chemistry property are discussed.展开更多
Benzophenones (BPs) are a class of widely used UV filters, which have been frequently detected within multiple environmental matrices. Disinfection is a necessary process in water treatment processes. The transforma...Benzophenones (BPs) are a class of widely used UV filters, which have been frequently detected within multiple environmental matrices. Disinfection is a necessary process in water treatment processes. The transformation behaviors and toxicity changes of 14 BP-type UV filters during chlorination disinfection treatment were investigated in this study. A new index, the acute toxicity formation potential, was proposed to evaluate the toxicity changes and potential risks of BP-type UV filters during chlorination treatment. It was found that 13 of 14 BP-type UV filters exhibited toxicity decreases in the chlorination disinfection process, more or less, while one showed a toxicity increase. The toxicity changes were dependent on substitution effects, such that 2,4-di-hydroxylated or 3-hydroxylated BPs exhibited significant toxicity decreases after chlorination treatment due to the ready cleavage of the aromatic ring. Importantly, the acute toxicity changes could be duplicated in an ambient water matrix.展开更多
The first laser excites a molecule to a lower triplet state and another sequential laser excites it resonantly to higher triplet states or makes it ionization. This two-step two-laser method provides a novel way to st...The first laser excites a molecule to a lower triplet state and another sequential laser excites it resonantly to higher triplet states or makes it ionization. This two-step two-laser method provides a novel way to study the electron transfer or charge transfer of excited molecules. The higher excited benzophenone and its radical cation can be observed under the time-resolved absorption method when it was excited to lower triplet state by one laser and another one exciting it to higher triplet states resonantly. The higher excited benzophenone molecules undergoing inter-molecular hydrogen abstraction with iso-propylalcohol molecules are faster than the lower ones.展开更多
Phytochemical investigation on the ethanol extract from the leaves of Aquitaria sinensis led to the isolation of five new benzophenone glycosides,aquilarinensides A-E(1-5).Their structures were elucidated by a combi...Phytochemical investigation on the ethanol extract from the leaves of Aquitaria sinensis led to the isolation of five new benzophenone glycosides,aquilarinensides A-E(1-5).Their structures were elucidated by a combination of 1D and 2D NMR,HRMS,and chemical analysis.展开更多
Benzophenones(BPs), a group of widely used UV filters, exert multiple, significant toxicity effects. The 11 BPs were selected as target compounds, and the photobacterium acute toxicity test and an index for acute to...Benzophenones(BPs), a group of widely used UV filters, exert multiple, significant toxicity effects. The 11 BPs were selected as target compounds, and the photobacterium acute toxicity test and an index for acute toxicity formation potential(ATFP) were used to evaluate the toxicity variation of BPs before and after a photoinduction–chlorination disinfection process.Orthogonal experiments were performed at different pH values and chlorine dosages. The characteristics of ATFP values for 11 BPs after a photoinduction–chlorination process can be summarized as follows:(1) The ATFPs decreased as the hydroxyl group number increased in BPs molecules.(2) For those BPs with the same hydroxyl group number, the ATFPs were higher when the hydroxyl groups were located at the 3-or 4-position than those at the 2-position; the BPs with hydroxyl groups distributed on two benzene rings had higher ATFPs than those on one ring.(3) Introducing a methoxyl group and sulfonic acid group into BP molecules increased the ATFP values.(4) The ATFPs were p H-dependent, the values of which were lowest at the neutral condition and highest at the acid condition.(5) The ATFPs increased and then decreased as the chlorine dosage increased. The results can be used as a reference to scientifically evaluate the environmental fate and potential risk of BPs in photoinduction–chlorination disinfection processes.展开更多
Benzophenone-type UV filters are a group of compounds widely used to protect human skin from damage of UV irradiation. Benzophenone-4(BP-4) was targeted to explore its transformation behaviors during chlorination di...Benzophenone-type UV filters are a group of compounds widely used to protect human skin from damage of UV irradiation. Benzophenone-4(BP-4) was targeted to explore its transformation behaviors during chlorination disinfection treatment in the presence of iodide ions. With the help of ultra performance liquid phase chromatograph and high-resolution quadrupole time-of-flight mass spectrometer, totally fifteen halogenated products were identified, and five out of them were iodinated products. The transformation mechanisms of BP-4 involved electrophilic substitution generating mono-or di-halogenated products,which would be oxidized into esters and further hydrolyzed into phenolic derivatives. The desulfonation and decarboxylation were observed in chlorination system either. Obeying the transformation pathways, five iodinated products formed. The p H conditions of chlorination system determined the reaction types of transformation and corresponding species of products. The more important was that, the acute toxicity had significant increase after chlorination treatment on BP-4, especially in the presence of iodide ions. When the chlorination treatment was performed on ambient water spiked with BP-4 and iodide ions,iodinated by-products could be detected.展开更多
In the previous paper we reported the photopolymerization of methyl methacrylate (MMA) initiated by benzophenone (BP)/aniline system. The proposed mechanism emphasized the interaction between the excited triplet BP an...In the previous paper we reported the photopolymerization of methyl methacrylate (MMA) initiated by benzophenone (BP)/aniline system. The proposed mechanism emphasized the interaction between the excited triplet BP and the ground state aniline to produce two kinds of radicals, among which only aniline radicals initiate the polymerization. We have also verified that each polymer chain contained one anilino end group on average. It展开更多
Time-resolved photoacoustic calorimetry has been expanded to allow the simultaneous determination of the dynamics and energetics of photoinduced reaction occurring on fast timescales, principally ns and μs. Data anal...Time-resolved photoacoustic calorimetry has been expanded to allow the simultaneous determination of the dynamics and energetics of photoinduced reaction occurring on fast timescales, principally ns and μs. Data analysis requires deconvolution of photoacoustic signals for a sum of exponentials. This technique with PZT transducer is now first applied to investigating the quenching of the benzophenone triplet state by K1 in methanol, and gives kinetic and thermodynamic results in excellent agreement with the previous value in acetonitrile.展开更多
基金The National Natural Science Foundation of China (No. 50378028)
文摘Comparative studies of ozonation alone, ceramic honeycomb-catalyzed and Mn-Fe-K modified ceramic honeycomb catalyzed ozonation processes have been undertaken with benzophenone as the model organic pollutant. The experimental results showed that the presence of Mn-Fe-K modified ceramic honeycombs significantly increased the removal rate of benzophenone and TOC compared with that achieved by ozonation alone or ceramic honeycomb-catalyzed ozonation. The electron paramagnetic resonance (EPR) experiments verified that higher benzophenone removal rate was attribute to more hydroxyl radicals generated in the Mn-Fe-K modified ceramic honeycomb-catalyzed ozonation. Under the conditions of this experiment, the degradation rate of all the three ozonation processes are increasing with the amount of catalyst, temperature and value of pH increased in the solution. We also investigated the effects of different process of ozone addition, the optimum conditions for preparing catalyst and influence of the Mn-Fe-K modified ceramic honeycomb after multiple-repeated use.
基金the National Natural Science Foundation of China(No.50473024)for its financial support.
文摘A benzophenone derivative photoinitiator, HBP-TDI-HQ-TDI-HBP (HTCTH), was synthesized based on 4-hydroxy benzophenone (HBP), toluene-2,4-diisocyanate (TDI) and hydroquinone (HQ). HTCTH was a more effective photoinitiator which had longer wavelength absorption in the UV-vis absorption spectra than the low molecular counterpart benzophenone (BP). It showed that both rate of polymerization (Rp) and final conversion (P) increased with increase of amine and HTCTH concentration in photopolymerization.
文摘A new benzophenone, securiphenone A was isolated from the roots of Securidaca inappendiculata. Its structure was. determined as 2, 3-methylenedioxy-4-methoxybenzophenone by spectroscopie methods.
基金Supported by the National Natural Science Foundation of China(No50973100)
文摘Dodecyl-benzophenone(DBP) and hexadecoxyl-benzophenone(HDBP) as type 11 photoinitiators used for radical photopolymerization systems were synthesized by Friedel-Crafts reaction, and characterized by 1H NMR and FTIR spectroscopy. The UV-Vis absorption spectra of DBP and HDBP, propitious to photopolymerization under a commercial mercury UV bulb are centered at 345 and 335 nm, respectively. HDBP has higher extinction coefficient than DBP, but lower photoinitiating efficiency. Their photoinitiating performances for EB605, a bisphenol A epoxy acrylate with 40%(mass fraction) tripropyleneglycol diacrylate (TPGDA), resin consisting of bisphenol A epoxy acrylate and tripropyleneglycol diacrylate in the presence of triethanolamine as a coinitiator were investigated by photo-differential scanning calorimetry(photo-DSC). DBP initiates the curing of acrylate more efficiently than HDBP, showing higher photopolymerization rate and unsaturation conversion, resulted from the poor compatibility of HDBP with the resin. The photoinitiating activity of DBP to epoxy acrylate resin is even higher than that of BP at lower loadings.
基金supported by the Beijing Nova Program(No.2007B030)the program for Agricultural products processing technology and storage engineering in Beijing key construction disciplines(No.PXM2009-014207- 078172).
文摘The effects of magnetic field on the graft ratio and stereoregularity of grafts of PVA-g-MMA in the presence ofbenzophenone during UV irradiation are discussed. By means of IR, it was found that the graft ratio was increased with the increment of magnetic field strength. Furthermore, application of relative weak magnetic field of 0.4 Tesla had been shown to substantially enhance the stereo-regularity of graft copolymer. The maximum stereo-regularity appeared when the graft ratio approached to 85% with the magnetic field of 1.2 Tesla (T). The resistance to moisture and heat resistance of the grafted copolymer in the presence of magnetic field were also improved.
基金The project was successively supported by the National Natural Science Foundation of China (No. 50073022, No 59773030, No. 59543002 and No. 5880104).
文摘The radical intermediates, the crosslink microstructures, and the reaction mechanism of benzophenone (BP)-photoinitiated crosslinking of low-density polyethylene (LDPE) and model compounds (MD) have been reviewed in detail. The spin-trapping electron spin resonance (ESR) spectra obtained from the LDPE/BP systems with spin-trap agents show that two kinds of polymer radical intermediates are mainly formed: tertiary carbon and secondary carbon radicals. The spin-trapping ESR studies of MD/BP systems give further evidence that photocrosslinking reactions of PE predominantly take place a sites of tertiary carbon, secondary carbon, and especially allylic carbon when available. The high resolution C-13-NMR spectra obtained from LDPE and MD systems show that the crosslink microstructures have H- and Y-type links and that their concentrations are of the same order. The fluorescence, ESR, C-13 and H-1-NMR spectra from the PE and MD systems demonstrate that the main photoreduction product of BP (PPB) is benzpinacol formed by the recombination of two diphenylhydroxymethyl (K-.) radical intermediates. Two new PPB products: an isomer of benzpinacol with quinoid structure, 1-phenylhydroxymethylene-4-diphenylhydroxymethyl-2,5-cyclobexadiene and three kinds of alpha-alkyl-benzhydrols have been detected and identified. These results provide new experimental evidence for elucidating the reaction mechanism in the BP-photoinitiated crosslinking of polyethylene.
基金support from National Natural Science Foundation of China(Nos. 20776165,20702065,20872184)"Key Foundation of Chongqing Science and Technology Commission"(No.CSTC 2008BA4020)+1 种基金"A Foundation for the Author of National Excellent Doctoral Dissertation of PR China(No.200735)"for financial supportsponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry as well(Nos.20071108- 1,20071108-5)
文摘New two-photon absorption dyes including benzophenone parts, p-N,N-diphenylamino-p'-phenacylstilbene (C1), 4,4-di-(4- benzoylstyrene)yltriphenylamine (C2) and 4,4',4'-tri(4-benzoylstyrene)yltriphenylamine (C3), were synthesized and characterized by ^1H NMR and elemental analysis. The ratio of the molar extinction coefficients of compounds was approximately equal to the ratio of the branch amount of the compounds, namely, C1:C2:C3 was 1:2:3. Extremely high fluorescence quantum yields were detected for these compounds. These molecules exhibited obvious two-photon upconcerted fluorescence as excited by 800 nm Ti:sapphire femtosecond laser.
文摘A novel binary photosensitization system composed of benzophenone (BP)/diphenyliodonium chloride (DPIOC) Ariethylamine (TEA), exhibiting a good photoresponse at near UV and visible light regions, was used as the initiator for photopolymerization of MMA. The radical photogeneration in the binary system consists mainly of two parallel reactions, i. e. , BP/TEA photohydrogen-abstraction and DPIOC/TEA complex photodecomposition, but the latter is more active than the former. The results of comparative study indicate that the rate of polymerization induced by the binary system (BDT)is remarkably higher than those by the corresponding single systems The polymerization rates are proportional to [BP]^(0.16), [DPIOC]^(0.32) [TEA]^(0.45) and [MMA]. The mechanism is also discussed.
文摘In the process of bulk photopolymerization of styrene initiated by AIBN decomposition polyvinyl benzophenone (PVB) can supply an effective cage for triplet-triplet energy transfer between PVB macromolecules and small molecules of AIBN to influence the molecular weight of polystyrene in weak magnetic field (less than 0.035T), that was different from the case of polyvinyl naphthalene (PVN) which supplied cages for this system only in the stronger magnetic field (more than 0.2 T) studies. It was found that in the same conditions, PVN could exert more tremendous influences on the bulk photopolymerizatiou system of styrene than PVB because in the stronger magnetic field the triplet PVN had much longer life time than PVB.
文摘Photoinduced charge transfer reaction of benzophenone(BP) with, mine was carried out in the vesicles of dicetyldimethylammonium bromide (DCDAB) over wide ranges of amine concentration (0. 01~4. 0M). Linear plots of φ^(-1) vs. [TEA]^(-1) at low concentration of amine (<0.02M) and Φ^(-1) vs. [TEA]^(-2) at high concentration were obtained. Kinetic data demonstrate that the electron transfer is promoted significantly by DCDAB vesicles and proton transfer becomes more efficient at high Rmlne concentrations, leading to a decrease of Kd/Kr and increase of Kh/Ke. The kinetic expressions of photoreaction of BP bound to DCDAB bilayer are developed.
基金supported by the National Natural Science Foundation of China(Nos.20877090,21077123,21377143)
文摘The brominated products, formed in chlorination treatment of benzophenone-4 in the presence of bromide ions, were identified, and the formation pathways were proposed.Under disinfection conditions, benzophenone-4 would undertake electrophilic substitution generating mono- or di-halogenated products, which would be oxidized to esters and further hydrolyzed to phenol derivatives. The generated catechol intermediate would be transformed into furan-like heterocyclic product. The product species were p H-dependent,while benzophenone-4 elimination was chlorine dose-dependent. When the chlorination treatment was performed on ambient water spiked with benzophenone-4 and bromide ions, most of brominated byproducts could be detected, and the acute toxicity significantly increased as well.
基金Project supported by the National Natural Science Foundation of China (Grant No. 29373110)the Key Laboratory of Photographic Chemistry, Chinese Academy of Sciences
文摘The chemically induced dynamic electron polarization (CIDEP) of photolyzed benzophenone radicals in the microheterogeneous phase systems has been made by using the time-resolved electron spin resonance (TRESR) spectrometer. In the AEO<sub>9</sub>/isoproanol/H<sub>2</sub>O/C<sub>8</sub>H<sub>18</sub> liquid crystal system, the TRESR spectrum of Ph<sub>2</sub>COH shows an unusual CIDEP of spin correlation radical pair (SCRP). The SCRP formation in these systems resulting from the character microenvironment and the related physical-chemistry property are discussed.
基金supported by the National Natural Science Foundation of China (No. 21377143, 21077123 and 20877090)
文摘Benzophenones (BPs) are a class of widely used UV filters, which have been frequently detected within multiple environmental matrices. Disinfection is a necessary process in water treatment processes. The transformation behaviors and toxicity changes of 14 BP-type UV filters during chlorination disinfection treatment were investigated in this study. A new index, the acute toxicity formation potential, was proposed to evaluate the toxicity changes and potential risks of BP-type UV filters during chlorination treatment. It was found that 13 of 14 BP-type UV filters exhibited toxicity decreases in the chlorination disinfection process, more or less, while one showed a toxicity increase. The toxicity changes were dependent on substitution effects, such that 2,4-di-hydroxylated or 3-hydroxylated BPs exhibited significant toxicity decreases after chlorination treatment due to the ready cleavage of the aromatic ring. Importantly, the acute toxicity changes could be duplicated in an ambient water matrix.
基金the National Natural Science Foundation of China (Grant No. 20073059).
文摘The first laser excites a molecule to a lower triplet state and another sequential laser excites it resonantly to higher triplet states or makes it ionization. This two-step two-laser method provides a novel way to study the electron transfer or charge transfer of excited molecules. The higher excited benzophenone and its radical cation can be observed under the time-resolved absorption method when it was excited to lower triplet state by one laser and another one exciting it to higher triplet states resonantly. The higher excited benzophenone molecules undergoing inter-molecular hydrogen abstraction with iso-propylalcohol molecules are faster than the lower ones.
基金supported by the Special Program for New Drug Innovation of the Ministry of Science and Technology, China(Nos.2009ZX311-004,2009ZX0308-004)
文摘Phytochemical investigation on the ethanol extract from the leaves of Aquitaria sinensis led to the isolation of five new benzophenone glycosides,aquilarinensides A-E(1-5).Their structures were elucidated by a combination of 1D and 2D NMR,HRMS,and chemical analysis.
基金supported by the National Natural Science Foundation of China(Nos.21577154,21377143)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB14040201)
文摘Benzophenones(BPs), a group of widely used UV filters, exert multiple, significant toxicity effects. The 11 BPs were selected as target compounds, and the photobacterium acute toxicity test and an index for acute toxicity formation potential(ATFP) were used to evaluate the toxicity variation of BPs before and after a photoinduction–chlorination disinfection process.Orthogonal experiments were performed at different pH values and chlorine dosages. The characteristics of ATFP values for 11 BPs after a photoinduction–chlorination process can be summarized as follows:(1) The ATFPs decreased as the hydroxyl group number increased in BPs molecules.(2) For those BPs with the same hydroxyl group number, the ATFPs were higher when the hydroxyl groups were located at the 3-or 4-position than those at the 2-position; the BPs with hydroxyl groups distributed on two benzene rings had higher ATFPs than those on one ring.(3) Introducing a methoxyl group and sulfonic acid group into BP molecules increased the ATFP values.(4) The ATFPs were p H-dependent, the values of which were lowest at the neutral condition and highest at the acid condition.(5) The ATFPs increased and then decreased as the chlorine dosage increased. The results can be used as a reference to scientifically evaluate the environmental fate and potential risk of BPs in photoinduction–chlorination disinfection processes.
基金supported by the National Natural Science Foundation of China (Nos.21577154, 21377143, 21590814, and 21402192)the Strategic Priority Research Program of the Chinese Academy of Sciences (No.XDB14040201)
文摘Benzophenone-type UV filters are a group of compounds widely used to protect human skin from damage of UV irradiation. Benzophenone-4(BP-4) was targeted to explore its transformation behaviors during chlorination disinfection treatment in the presence of iodide ions. With the help of ultra performance liquid phase chromatograph and high-resolution quadrupole time-of-flight mass spectrometer, totally fifteen halogenated products were identified, and five out of them were iodinated products. The transformation mechanisms of BP-4 involved electrophilic substitution generating mono-or di-halogenated products,which would be oxidized into esters and further hydrolyzed into phenolic derivatives. The desulfonation and decarboxylation were observed in chlorination system either. Obeying the transformation pathways, five iodinated products formed. The p H conditions of chlorination system determined the reaction types of transformation and corresponding species of products. The more important was that, the acute toxicity had significant increase after chlorination treatment on BP-4, especially in the presence of iodide ions. When the chlorination treatment was performed on ambient water spiked with BP-4 and iodide ions,iodinated by-products could be detected.
文摘In the previous paper we reported the photopolymerization of methyl methacrylate (MMA) initiated by benzophenone (BP)/aniline system. The proposed mechanism emphasized the interaction between the excited triplet BP and the ground state aniline to produce two kinds of radicals, among which only aniline radicals initiate the polymerization. We have also verified that each polymer chain contained one anilino end group on average. It
文摘Time-resolved photoacoustic calorimetry has been expanded to allow the simultaneous determination of the dynamics and energetics of photoinduced reaction occurring on fast timescales, principally ns and μs. Data analysis requires deconvolution of photoacoustic signals for a sum of exponentials. This technique with PZT transducer is now first applied to investigating the quenching of the benzophenone triplet state by K1 in methanol, and gives kinetic and thermodynamic results in excellent agreement with the previous value in acetonitrile.