The atmospheric concentrations of carbonyls and BTEX （benzene,toluene,ethylbenzene,m,p-xylene and o-xylene） were measured simultaneously at a same sampling site in Beijing from September 2008 to August 2010.The aver...The atmospheric concentrations of carbonyls and BTEX （benzene,toluene,ethylbenzene,m,p-xylene and o-xylene） were measured simultaneously at a same sampling site in Beijing from September 2008 to August 2010.The average concentrations of the total measured carbonyls during autumn,winter,spring,and summer were 37.7,31.3,39.7,50.5 μg/m 3,respectively,and maximal values for their diurnal variations usually happened at noontime.In contrast to carbonyls,the average concentrations of the total measured BTEX during the four seasons were 27.2,31.9,23.2,19.1 μg/m 3,respectively,andminimal values for their diurnal variations always occurred in the early afternoon.The average concentration for carbonyls increased about 24% from September 2008–August 2009 to September 2009–August 2010,for BTEX,increased about 15%.Integrated life time cancer risks for three carcinogens （benzene,formaldehyde and acetaldehyde） in Beijing exceeded the value of 1E-06,and the hazard quotient （HQ） of non-cancer risk of exposure to formaldehyde exceeded unity.展开更多
Ambient carbonyls were continuously observed in the field during a heavy ozone pollution episode in Chengdu, China from August 4 to August 19, 2019, and the pollution characteristics, atmospheric photochemical reactiv...Ambient carbonyls were continuously observed in the field during a heavy ozone pollution episode in Chengdu, China from August 4 to August 19, 2019, and the pollution characteristics, atmospheric photochemical reactivity, human health risk, and sources of carbonyls were analyzed. Fifteen carbonyls were quantified with average total mixing ratios of 20.38 ppbv Formaldehyde(9.86 ppbv), acetone(4.41 ppbv), and acetaldehyde(3.57 ppbv) were the three most abundant carbonyls. During the heavy ozone pollution episode, the concentration of carbonyls was found to be higher on pollution days than on the clean days, and relatively higher in the daytime, especially at noon on the pollution days. This was influenced by the intensity of photochemical reactions and precipitation. The “weekend effect” with the concentration of carbonyls was higher on the weekends than on the weekdays was pointed out. Formaldehyde, acetaldehyde and hexaldehyde were the dominant oxidative species during the observation. The carcinogenic and non-carcinogenic risk values of formaldehyde and acetaldehyde were higher on pollution days than on clean days, and these values were higher compared with those of other cities in China and abroad. Long-term exposure to these compounds should therefore be avoided. Diagnostic ratios and correlation analysis together with backward trajectory analysis showed that primary emission and secondary formation accounted 66%-76% and 24%–34% of carbonyls in Chengdu, respectively, with primary emission being the main sources of carbonyls, and carbonyls from the surrounding cities and emission from natural sources also had a significant contribution to the carbonyls in Chengdu.展开更多
Ground-level ozone contamination has been globally an urban air quality issue,particularly for China,which has recently made significant progress in purifying its sky.Unregulated exhaust emissions from motor vehicles,...Ground-level ozone contamination has been globally an urban air quality issue,particularly for China,which has recently made significant progress in purifying its sky.Unregulated exhaust emissions from motor vehicles,predominantly carbonyls and volatile organic compounds(VOCs),are among the leading contributors to ozone formation.In this chassislevel study,the unregulated emissions from five China-5 certified gasoline/CNG bi-fuel taxis,along with their ozone forming potential(OFP),were evaluated.It is found that carbonyls and VOCs were mainly emitted during the starting phase no matter the engine was cold or hot.Compared to gasoline,CNG fueling reduced VOCs emissions on a large scale,especially in the starting phase,but had elevated carbonyls.On a fleet average,CNG fueling derived 15%and 46%less OFP than gasoline in cold-and hot-start tests,respectively.VOCs contributed to over 90%of the total OFP of the exhaust.In terms of alleviating ground-level ozone contamination,CNG is a feasible alternative to gasoline on light-duty vehicles.展开更多
Oxygen-isotopic labelings play important roles in identifying and understanding chemical and biological processes.Direct C=O to C=^(18)O or C=^(17)O conversion in a single step leading to labeled compounds can allevia...Oxygen-isotopic labelings play important roles in identifying and understanding chemical and biological processes.Direct C=O to C=^(18)O or C=^(17)O conversion in a single step leading to labeled compounds can alleviate synthetic burdens without the need for resynthesis.Here we describe a photocatalytic oxygenisotopic labeling protocol that can efficiently and selectively install ^(18)O and ^(17)O on carbonyls of ketones and aldehydes via oxygen isotope exchange with oxygen-isotopic waters(H_(2)^(18)O or H_(2)^(17)O)as the sources of oxygen isotopes,in which light and oxygen-enabled sodium alkanesulfinates catalyzed this process.This strategy was extended to the in-situ formed ketones from the photocatalytic aerobic oxidation of alkyl arenes and secondary alcohols.Furthermore,reduction of the oxygen-isotopically labeled aldehydes with NaBH_(4) provided the corresponding oxygen-isotopically labeled primary alcohols.We believe that the oxygen-isotopically labeling method will be widely used in chemistry,biology and medicine fields.展开更多
Atmospheric carbonyl compounds play significant roles in the cycling of radicals and have exhibited surprisingly high levels in winter that were well correlated to particulate matter,for which the reason have not been...Atmospheric carbonyl compounds play significant roles in the cycling of radicals and have exhibited surprisingly high levels in winter that were well correlated to particulate matter,for which the reason have not been clearly elucidated.Here we measured carbonyl compounds and other trace gasses together with PM_(2.5)over urban Jinan in North China Plain during the winter.Markedly higher carbonyl concentrations(average:14.63±4.21 ppbv)were found during wintertime haze pollution,about one to three-times relative to those on nonhaze days,with slight difference in chemical composition except formaldehyde(HCHO).HCHO(3.68 ppbv),acetone(3.17 ppbv),and acetaldehyde(CH_3CHO)(2.83 ppbv)were the three most abundant species,accounting for~75% of the total carbonylson both haze and non-haze days.Results from observational-based model(OBM)with atmospheric oxidation capacity(AOC)indicated that AOC significantly increased with the increasing carbonyls during the winter haze events.Carbonyl photolysis have supplied key oxidants such as RO_(2) and HO_(2),and thereby enhancing the formation of fine particles and secondary organic aerosols,elucidating the observed haze-carbonyls inter-correlation.Diurnal variation with carbonyls exhibiting peak values at early-noon and night highlighted the combined contribution of both secondary formation and primary diesel-fuel sources.1-butene was further confirmed to be the major precursor for HCHO.This study confirms the great contribution of carbonyls to AOC,and also suggests that reducing the emissions of carbonyls would be an effective way to mitigate haze pollution in urban area of the NCP region.展开更多
The measurements of atmospheric carbonyls concentrations in Beijing were conducted from 12 July to 8 October, 2008, covering the periods of the 2008 Olympic Games and Paralympic Games. Six carbonyls, including formald...The measurements of atmospheric carbonyls concentrations in Beijing were conducted from 12 July to 8 October, 2008, covering the periods of the 2008 Olympic Games and Paralympic Games. Six carbonyls, including formaldehyde, acetaldehyde, acetone, butyraldehyde, valeraldehyde, and hexaldehyde, were identified in all air samples. The total average concentrations of these carbonyls before, during, and after traffic restriction were （48.1 ± 15.2）, （36.6 ± 14.5） and （23.4± 12.3） μg/m^3, respectively. Compared with the period after traffic restriction, the distinct high concentrations of the carbonyls before and during traffic restriction were primarily ascribed to the remarkable contribution of photochemical reactions. With respect to our previous investigation in the summer of 2005, the reductions of formaldehyde, acetaldehyde and acetone during traffic restriction period were about 64%, 47% and 27%, respectively, indicating that the air cleaning actions adopted by the Chinese government for the two games were efficient. The lowest levels of atmospheric carbonyls and the extremely high composition proportion of acetone after the traffic restriction were mainly attributed to the long-term effect of the control measures for the two games.展开更多
In their recent Journal of Environmental Sciences publication,Wang and colleagues provide field evidence that industrial activities can contribute substantially to atmospheric carbonyl concentrations（Wang et al.,2015...In their recent Journal of Environmental Sciences publication,Wang and colleagues provide field evidence that industrial activities can contribute substantially to atmospheric carbonyl concentrations（Wang et al.,2015）.These results may helpto explain underestimations of carbonyl emissions in currently available emission inventories,and highlight the need for an improved understanding of industrial sources of this class of compounds.展开更多
Homoleptic mononuclear and binuclear ruthenium carbonyls Ru(CO)n(n=3―5) and Ru2(CO)n(n=8,9) have been investigated using density functional theory.Sixteen isomers are obtained.For Ru(CO)5,the lowest-energy structure ...Homoleptic mononuclear and binuclear ruthenium carbonyls Ru(CO)n(n=3―5) and Ru2(CO)n(n=8,9) have been investigated using density functional theory.Sixteen isomers are obtained.For Ru(CO)5,the lowest-energy structure is the singlet D3h trigonal bipyramid.Similar to Os(CO)5,the distorted square pyramid isomer with C2v symmetry lies ～7 kJ·mol-1 higher in energy.For the unsaturated mononuclear ruthenium carbonyls Ru(CO)4 and Ru(CO)3,a singlet structure with C2v symmetry and a Cs bent Tshaped structure are the lowest-energy structures,respectively.The global minimum for the Ru2(CO)9 is a singly bridged(CO)4Ru(μ-CO)Ru(CO)4 structure.A triply bridged Ru2(CO)6(μ-CO)3 structure analogous to the known Fe2(CO)9 structure is predicted to lie very close in energy to the global minimum.For Ru2(CO)8,the doubly bridged C2 structure is predicted to be the global minimum.For the lowest-energy structures of M2(CO)n(M=Fe,Ru,Os,n=9,8),it is found that both iron and ruthenium are favored to form structures containing more bridging carbonyl groups,while osmium prefers to have structures with less bridging carbonyl groups.The study of dissociation energy shows that the dissociation of Ru2(CO)9 into the mononuclear fragments Ru(CO)5+Ru(CO)4 is a less energetically demanding process than the dissociation of one carbonyl group from Ru2(CO)9 to give Ru2(CO)8.展开更多
The inhibition capacity of bound-polyphenol rich insoluble dietary fiber(BP-IDF)from highland barley to carbonyl compounds was studied during in vitro gastrointestinal(GI)digestion.More than 97%of fiber-bound polyphen...The inhibition capacity of bound-polyphenol rich insoluble dietary fiber(BP-IDF)from highland barley to carbonyl compounds was studied during in vitro gastrointestinal(GI)digestion.More than 97%of fiber-bound polyphenols were still presented in highland barley BP-IDF(HBBP-IDF)after GI digestion.The fiber-bound polyphenols in HBBP-IDF effectively inhibit carbonyls when simultaneously digested with cookies and French fries and exhibited more pronounced effect during gastric digestion stage,with inhibition of 63.4%for methylglyoxal,54.3%for glyoxal,47.6%for malondialdehyde and 42.4%for 4-hydroxy-2-nonenel,respectively.These findings suggest that HBBP-IDF could be use as functional ingredients able to inhibit the formation of carbonyls during digestion process and maintain healthful digestive tract environment.展开更多
Volatile organic compounds （VOCs） and carbonyl compounds were measured both indoors and outdoors in 50 residences of Beijing in heating （December, 2011） and non-heating seasons （April/May, 2012）. SUMMA canisters...Volatile organic compounds （VOCs） and carbonyl compounds were measured both indoors and outdoors in 50 residences of Beijing in heating （December, 2011） and non-heating seasons （April/May, 2012）. SUMMA canisters for VOCs and diffusive samplers for carbonyl compounds were deployed for 24 h at each site, and 94 compounds were quantified. Formaldehyde, acetone and acetaldehyde were the most abundant carbonyl compounds both indoors and outdoors with indoor median concentrations being 32.1, 21.7 and 15.3 μg·m-3, respec- tively. Ethane （17.6 μg·m-3）, toluene （14.4 μg·m-3）, pro- pane （11.2 μg·m-3）, ethene （8.40 μg·m-3）, n-butane （6.87 μg·m-3）, and benzene （5.95 μg·m-3） showed the high median concentrations in indoor air. Dichloromethane, p- dichlorobenzene （p-DCB） and toluene exhibited extremely high levels in some residences, which were related with a number of indoor emission sources. Moreover, isoprene, p- dichlorobenzene and carbonyls showed median indoor/ outdoor （I/O） ratios larger than 3, indicating their indoor sources were prevailing. Chlorinated compounds like CFCs were mainly from outdoor sources for their I/O ratios being less than 1. In addition, indoor concentrations between two sampling seasons varied with different compounds. Carbonyl compounds and some chlorinated compounds had higher concentrations in the non-heating season, while alkanes, alkenes, aromatic compounds showed an increase in the heating season. Indoor concentration of VOCs and carbonyls were influenced by locations, interior decorations and indoor activities, however the specific sources for indoor VOCs and carbonyls could not be easily identified. The findings obtained in this study would significantly enhance our understandings on the prevalent and abundant species of VOCs as well as their concentrations and sources in Beijing residences.展开更多
Aromatic carbonyls have evoked sustained attention in the field of room-temperature phosphorescence(RTP).The introduction of carbonyl groups is a general way to achieve RTP for their effective intersystem crossing(ISC...Aromatic carbonyls have evoked sustained attention in the field of room-temperature phosphorescence(RTP).The introduction of carbonyl groups is a general way to achieve RTP for their effective intersystem crossing(ISC)by improving spin-orbit coupling(SOC).With further molecular design and processing strategies,aromatic carbonyls materials with multi-functional and high efficiency ultralong organic phosphorescence(UOP)can be obtained.This review summarizes the mechanism of aromatic carbonyls with UOP in pure aromatic carbonyls and their multi-component systems.Some detailed strategies for improving UOP performance are further introduced.The summary and outlook are presented to expound on the advances and lack of aromatic carbonyls.Further development directions and requirements are also put forward.展开更多
Arsenic-related oxidative stress and resultant diseases have attracted global concern,while longitudinal studies are scarce.To assess the relationship between arsenic exposure and systemic oxidative damage,we performe...Arsenic-related oxidative stress and resultant diseases have attracted global concern,while longitudinal studies are scarce.To assess the relationship between arsenic exposure and systemic oxidative damage,we performed two repeatedmeasures among 5236 observations(4067 participants)in theWuhan-Zhuhai cohort at the baseline and follow-up after 3 years.Urinary total arsenic,biomarkers of DNA oxidative damage(8-hydroxy-2-deoxyguanosine(8-OHdG)),lipid peroxidation(8-isoprostaglandin F2alpha(8-isoPGF2α)),and protein oxidative damage(protein carbonyls(PCO))were detected for all observations.Here we used linearmixed models to estimate the cross-sectional and longitudinal associations between arsenic exposure and oxidative damage.Exposure-response curves were constructed by utilizing the generalized additive mixed models with thin plate regressions.After adjusting for potential confounders,arsenic level was significantly and positively related to the levels of global oxidative damage and their annual increased rates in dose-response manners.In cross-sectional analyses,each 1%increase in arsenic levelwas associated with a 0.406%(95%confidence interval(CI):0.379%to 0.433%),0.360%(0.301%to 0.420%),and 0.079%(0.055%to 0.103%)increase in 8-isoPGF2α,8-OHdG,and PCO,respectively.More importantly,arsenic was further found to be associated with increased annual change rates of 8-isoPGF2α(β:0.147;95%CI:0.130 to 0.164),8-OHdG(0.155;0.118 to 0.192),and PCO(0.050;0.035 to 0.064)in the longitudinal analyses.Our study suggested that arsenic exposurewas not only positively related with global oxidative damage to lipid,DNA,and protein in cross-sectional analyses,but also associated with annual increased rates of these biomarkers in dose-dependent manners.展开更多
The photochemical conversion of SO_(2) to sulfates on 4-(benzoyl)benzoic acid(4-BBA)was investigated deeply in the presence of anionic and cationic surfactants.The types of surfactants determined their effect behavior...The photochemical conversion of SO_(2) to sulfates on 4-(benzoyl)benzoic acid(4-BBA)was investigated deeply in the presence of anionic and cationic surfactants.The types of surfactants determined their effect behaviors,and cationic surfactants can significantly enhance the SO_(2) oxidation on 4-BBA under irradiation,as shown by larger SO_(2) uptake coefficients and sulfate production.Hydrophilic moieties in cationic surfactants have a greater enhancement effect on the photochemical conversion of SO_(2) to sulfates than the corresponding hydrophobic moieties.Cationic surfactants obviously increased the accumulation of H_(2)O on the surface,which was proved to be the main factor influencing the SO_(2) uptake and the sulfate formation on 4-BBA.SO_(2) lifetime and sulfate formation rate in the mixture system of photosensitive substances with surfactants were evaluated to be 2.25 days and 0.09μg/(m^(3)·h),respectively.展开更多
Chiral carbonyl compounds frequently occur in natural products and pharmaceuticals. Additionally, they serve as important intermediates in organic synthesis. Transition metal-catalyzed asymmetric carbonylative cross-c...Chiral carbonyl compounds frequently occur in natural products and pharmaceuticals. Additionally, they serve as important intermediates in organic synthesis. Transition metal-catalyzed asymmetric carbonylative cross-coupling reactions are among the most straightforward and effective methods for synthesizing chiral carbonyl compounds, including esters, amides, and ketones. The advances in asymmetric carbonylative cross-coupling reactions using various O-, N-, C-, and S-containing nucleophiles or electrophiles over the past decade are summarized.展开更多
Polyhydroxyalkanoate(PHA),a well-known biodegradable polymer,featuresβ-lactones as its monomers,which can be selectively synthesized through ring-expansion carbonylation of epoxides using well-defined[Lewis acid]^(+)...Polyhydroxyalkanoate(PHA),a well-known biodegradable polymer,featuresβ-lactones as its monomers,which can be selectively synthesized through ring-expansion carbonylation of epoxides using well-defined[Lewis acid]^(+)[Co(CO)_(4)]^(-)catalysts.However,the decomposition of[Co(CO)_(4)]^(-)species at temperatures exceeding 80℃presents a hurdle for the development of commercially viable processes under high-temperature reaction conditions to reduce reaction time.Drawing insights from stable{(acyl)Co(CO)n}intermediates involved in historical HCo(CO)_(4)-catalyzed hydroformylation processes,we sought to the high-temperature catalytic activity of epoxide ring-expansion carbonylation.The developed catalyst system,[(acetyl)Co(CO)_(2)dppp]and[(TPP)CrCl],exhibited exceptional catalytic performance with an unprecedented initial turnover frequency of 4700 h^(-1)at 100℃and a turnover numbers of 93000.Notably,the catalyst displayed outstanding stability,operating at 80℃for 168 h while selectively generatingβ-lactones.展开更多
The amide moiety plays an important role as a powerful bioactive backbone,and as the synthetic chemistry community moves toward more sp^(3)-rich scaffolds,alkyl halides have become the feedstock of choice for obtainin...The amide moiety plays an important role as a powerful bioactive backbone,and as the synthetic chemistry community moves toward more sp^(3)-rich scaffolds,alkyl halides have become the feedstock of choice for obtaining carbonylation products.With the development of photoredox catalysis,several aminocarbonylation systems for alkyl halides were developed which usually require transition metal catalysis.Considering the demands for green sustainable chemical synthesis,here we report a metal-free,exogenous catalyst-free aminocarbonylation reaction of alkyl iodides under atmospheric pressure of carbon monoxide.Through a combination of EDA and XAT strategies,the reaction occurs efficiently under only light irradiation at room temperature.展开更多
Microplastics(MPs) are an emerging environmental pollutant and have penetrated the most remote and primitive areas. MPs degradation has received widespread attention. Manganese(Mn) is a highly reactive metal element i...Microplastics(MPs) are an emerging environmental pollutant and have penetrated the most remote and primitive areas. MPs degradation has received widespread attention. Manganese(Mn) is a highly reactive metal element in the environment, yet its contribution to MPs degradation remains unclear. Herein,we simulated the aging of polyethylene MPs with Mn(Ⅱ) under aqueous conditions at pH 5 and 8 for720 days. Mn greatly promoted the MPs degradation, and the average particle sizes of polyethylene MPs were reduced from 9.2 μm to 5.9 μm after aging at pH 5 under light irradiation for 720 days. Plenty of oxygen-containing groups were generated on the MPs surfaces, and the carbonyl index remarkably increased, reaching four times that of the control without adding Mn. Mechanistically, the adsorbed Mn(Ⅱ)on the MPs surfaces were primarily oxidized to high-valence Mn(Ⅲ/Ⅳ) profited from the photoproduced radicals, followed by the MPs oxidation via Mn(Ⅲ/Ⅳ), which were reduced to regenerate Mn(Ⅱ), initiating a new redox cycling. During the degradation, dissolved organic matter was continuously released, mainly including bisphenol A and phthalic acid esters. Mn acts as a catalyst to accelerate the MPs degradation by redox cycling. Our results provide a new insight into the mechanisms of abiotic degradation of MPs in aqueous environments.展开更多
Carboxylic acid derivatives withα-quaternary carbon center are one of the most ubiquitous moieties in synthetic and medicinal chemistry.Hence,novel and efficient synthetic methods towards carboxylic acid derivatives ...Carboxylic acid derivatives withα-quaternary carbon center are one of the most ubiquitous moieties in synthetic and medicinal chemistry.Hence,novel and efficient synthetic methods towards carboxylic acid derivatives withα-quaternary carbon remain in high demand.However,most of the precursors of these complex compounds are not easy to prepare.Reported herein is a carbonylative five-component synthesis of amides and esters withα-quaternary carbon center enabled by palladium catalysis from abundant acrylonitrile,carbon monoxide,fluoroalkyl halides,and nucleophiles.Diverse amides and esters withα-quaternary carbon which contain difluoromethyl or perfluoroalkyl moiety were prepared in good to excellent yields,providing an efficient synthetic platform for sequential transformations.展开更多
Protein damage repair and prevention are important objectives in skin care industry.Skin protein damage or modifications such as glycation,carbonylation or oxidation,have a significant impact on its function,therefore...Protein damage repair and prevention are important objectives in skin care industry.Skin protein damage or modifications such as glycation,carbonylation or oxidation,have a significant impact on its function,therefore directly influencing various skin functions or properties including skin appearance.However,there is a lack of comprehensive methods to visualize and assess the protein damage.In this article,we present a three-channel imaging approach to simultaneously visualize and quantitatively evaluate protein oxidation,protein glycation and carbonylation in a full-thickness skin model.We successfully visualized and quantified the impact of the multiple stimuli(ultraviolet radiation A(UVA)and/or methylglyoxal)as well as treatment effect of positive control(vitamins C and E)with this method.Our findings indicate that multiple stimuli exhibit synergistic effects on protein damage.Furthermore,we evaluated a unique combination of skin care ingredients which demonstrated an excellent efficacy in resisting protein damage.Further research revealed that three ingredients of the combination upregulate autophagy in cells,which may contribute to remove damaged proteins and maintain protein quality homeostasis.This method provides a holistic assessment of protein damages and can be employed to evaluate the impact of various stimuli or to assess the efficacy of skin care ingredients in mitigating such damage.展开更多
Herein,we report an iron-promoted carbonylation-rearrangement ofα-aminoaryl-tethered alkylidene cyclopropanes with CO_(2)to generate quinolinofuran derivatives.A variety of quinolinofuran derivatives are obtained in ...Herein,we report an iron-promoted carbonylation-rearrangement ofα-aminoaryl-tethered alkylidene cyclopropanes with CO_(2)to generate quinolinofuran derivatives.A variety of quinolinofuran derivatives are obtained in moderate to excellent yields,and two promising luminescent material molecules have been synthesized using the developed method.The Lewis acid Fe Cl_(3)was introduced into this reaction,which effectively promoted the ring opening and rearrangement of cyclopropanes.This reaction features a broad substrate scope,satisfactory functional group tolerance,facile scalability,and easy derivatization of the products.展开更多
基金supported by the National Natural Science Foundation of China (No. 41075094,40830101, 21177140,20977097)the National Basic Research and the Development Program (973) of China (No. 2010CB732304)+1 种基金the Special Fund for Environmental Research in the Public Interest (No. 201009001)the National Water Special Project (No. 2009ZX07210-009)
文摘The atmospheric concentrations of carbonyls and BTEX （benzene,toluene,ethylbenzene,m,p-xylene and o-xylene） were measured simultaneously at a same sampling site in Beijing from September 2008 to August 2010.The average concentrations of the total measured carbonyls during autumn,winter,spring,and summer were 37.7,31.3,39.7,50.5 μg/m 3,respectively,and maximal values for their diurnal variations usually happened at noontime.In contrast to carbonyls,the average concentrations of the total measured BTEX during the four seasons were 27.2,31.9,23.2,19.1 μg/m 3,respectively,andminimal values for their diurnal variations always occurred in the early afternoon.The average concentration for carbonyls increased about 24% from September 2008–August 2009 to September 2009–August 2010,for BTEX,increased about 15%.Integrated life time cancer risks for three carcinogens （benzene,formaldehyde and acetaldehyde） in Beijing exceeded the value of 1E-06,and the hazard quotient （HQ） of non-cancer risk of exposure to formaldehyde exceeded unity.
基金financial support from the project Analysis of Multiple Causes of Atmospheric Ozone Pollution in Urban Agglomerations of Chengdu Plain and Development of Management,Prevention,Control System of Sichuan AcademyofEnvironmental Sciences (No.510201201905430)the Fundamental Research Funds for Central Public Welfare Scientific Research Institutes of China,Chinese Research Academy of Environmental Sciences (No.2019YSKY-012,No.2019YSKY-018,No.2019YSKY-013)+1 种基金Peking UniversityChengdu Academy of Environmental Protection and Sciences for their vigorous support during the field observation.
文摘Ambient carbonyls were continuously observed in the field during a heavy ozone pollution episode in Chengdu, China from August 4 to August 19, 2019, and the pollution characteristics, atmospheric photochemical reactivity, human health risk, and sources of carbonyls were analyzed. Fifteen carbonyls were quantified with average total mixing ratios of 20.38 ppbv Formaldehyde(9.86 ppbv), acetone(4.41 ppbv), and acetaldehyde(3.57 ppbv) were the three most abundant carbonyls. During the heavy ozone pollution episode, the concentration of carbonyls was found to be higher on pollution days than on the clean days, and relatively higher in the daytime, especially at noon on the pollution days. This was influenced by the intensity of photochemical reactions and precipitation. The “weekend effect” with the concentration of carbonyls was higher on the weekends than on the weekdays was pointed out. Formaldehyde, acetaldehyde and hexaldehyde were the dominant oxidative species during the observation. The carcinogenic and non-carcinogenic risk values of formaldehyde and acetaldehyde were higher on pollution days than on clean days, and these values were higher compared with those of other cities in China and abroad. Long-term exposure to these compounds should therefore be avoided. Diagnostic ratios and correlation analysis together with backward trajectory analysis showed that primary emission and secondary formation accounted 66%-76% and 24%–34% of carbonyls in Chengdu, respectively, with primary emission being the main sources of carbonyls, and carbonyls from the surrounding cities and emission from natural sources also had a significant contribution to the carbonyls in Chengdu.
基金received funding support from the National Natural Science Foundation of China (No.52272342)the National Engineering Laboratory for Mobile Source Emission Control Technology,China (No.NELMS2018A17).
文摘Ground-level ozone contamination has been globally an urban air quality issue,particularly for China,which has recently made significant progress in purifying its sky.Unregulated exhaust emissions from motor vehicles,predominantly carbonyls and volatile organic compounds(VOCs),are among the leading contributors to ozone formation.In this chassislevel study,the unregulated emissions from five China-5 certified gasoline/CNG bi-fuel taxis,along with their ozone forming potential(OFP),were evaluated.It is found that carbonyls and VOCs were mainly emitted during the starting phase no matter the engine was cold or hot.Compared to gasoline,CNG fueling reduced VOCs emissions on a large scale,especially in the starting phase,but had elevated carbonyls.On a fleet average,CNG fueling derived 15%and 46%less OFP than gasoline in cold-and hot-start tests,respectively.VOCs contributed to over 90%of the total OFP of the exhaust.In terms of alleviating ground-level ozone contamination,CNG is a feasible alternative to gasoline on light-duty vehicles.
基金supported by Natural Science Foundation of Beijing Municipality(No.2222011)National Natural Science Foundation of China(No.22077074)China Postdoctoral Science Foundation(No.2021M701869).
文摘Oxygen-isotopic labelings play important roles in identifying and understanding chemical and biological processes.Direct C=O to C=^(18)O or C=^(17)O conversion in a single step leading to labeled compounds can alleviate synthetic burdens without the need for resynthesis.Here we describe a photocatalytic oxygenisotopic labeling protocol that can efficiently and selectively install ^(18)O and ^(17)O on carbonyls of ketones and aldehydes via oxygen isotope exchange with oxygen-isotopic waters(H_(2)^(18)O or H_(2)^(17)O)as the sources of oxygen isotopes,in which light and oxygen-enabled sodium alkanesulfinates catalyzed this process.This strategy was extended to the in-situ formed ketones from the photocatalytic aerobic oxidation of alkyl arenes and secondary alcohols.Furthermore,reduction of the oxygen-isotopically labeled aldehydes with NaBH_(4) provided the corresponding oxygen-isotopically labeled primary alcohols.We believe that the oxygen-isotopically labeling method will be widely used in chemistry,biology and medicine fields.
基金supported by the National Natural Science Foundation of China(Nos.42005092,42275127,42075112and 41775127)the Natural Science Foundation of Shandong Province(No.ZR2020QD058)。
文摘Atmospheric carbonyl compounds play significant roles in the cycling of radicals and have exhibited surprisingly high levels in winter that were well correlated to particulate matter,for which the reason have not been clearly elucidated.Here we measured carbonyl compounds and other trace gasses together with PM_(2.5)over urban Jinan in North China Plain during the winter.Markedly higher carbonyl concentrations(average:14.63±4.21 ppbv)were found during wintertime haze pollution,about one to three-times relative to those on nonhaze days,with slight difference in chemical composition except formaldehyde(HCHO).HCHO(3.68 ppbv),acetone(3.17 ppbv),and acetaldehyde(CH_3CHO)(2.83 ppbv)were the three most abundant species,accounting for~75% of the total carbonylson both haze and non-haze days.Results from observational-based model(OBM)with atmospheric oxidation capacity(AOC)indicated that AOC significantly increased with the increasing carbonyls during the winter haze events.Carbonyl photolysis have supplied key oxidants such as RO_(2) and HO_(2),and thereby enhancing the formation of fine particles and secondary organic aerosols,elucidating the observed haze-carbonyls inter-correlation.Diurnal variation with carbonyls exhibiting peak values at early-noon and night highlighted the combined contribution of both secondary formation and primary diesel-fuel sources.1-butene was further confirmed to be the major precursor for HCHO.This study confirms the great contribution of carbonyls to AOC,and also suggests that reducing the emissions of carbonyls would be an effective way to mitigate haze pollution in urban area of the NCP region.
基金supported by the National Natural Science Foundation of China (No. 20977097,40830101, 41075094)the Chinese Academy of Sciences (No. KZCX2-YW-Q02-03)+1 种基金the Platform Construction of Introducing Central Resources in Beijing (No.PXM2008 178305 06995)the National Basic Research and Development Program (973) of China (No.2010CB732304)
文摘The measurements of atmospheric carbonyls concentrations in Beijing were conducted from 12 July to 8 October, 2008, covering the periods of the 2008 Olympic Games and Paralympic Games. Six carbonyls, including formaldehyde, acetaldehyde, acetone, butyraldehyde, valeraldehyde, and hexaldehyde, were identified in all air samples. The total average concentrations of these carbonyls before, during, and after traffic restriction were （48.1 ± 15.2）, （36.6 ± 14.5） and （23.4± 12.3） μg/m^3, respectively. Compared with the period after traffic restriction, the distinct high concentrations of the carbonyls before and during traffic restriction were primarily ascribed to the remarkable contribution of photochemical reactions. With respect to our previous investigation in the summer of 2005, the reductions of formaldehyde, acetaldehyde and acetone during traffic restriction period were about 64%, 47% and 27%, respectively, indicating that the air cleaning actions adopted by the Chinese government for the two games were efficient. The lowest levels of atmospheric carbonyls and the extremely high composition proportion of acetone after the traffic restriction were mainly attributed to the long-term effect of the control measures for the two games.
文摘In their recent Journal of Environmental Sciences publication,Wang and colleagues provide field evidence that industrial activities can contribute substantially to atmospheric carbonyl concentrations（Wang et al.,2015）.These results may helpto explain underestimations of carbonyl emissions in currently available emission inventories,and highlight the need for an improved understanding of industrial sources of this class of compounds.
基金Supported by the National Natural Science Foundation of China (Grant Nos. 20873045 and 20973066)
文摘Homoleptic mononuclear and binuclear ruthenium carbonyls Ru(CO)n(n=3―5) and Ru2(CO)n(n=8,9) have been investigated using density functional theory.Sixteen isomers are obtained.For Ru(CO)5,the lowest-energy structure is the singlet D3h trigonal bipyramid.Similar to Os(CO)5,the distorted square pyramid isomer with C2v symmetry lies ～7 kJ·mol-1 higher in energy.For the unsaturated mononuclear ruthenium carbonyls Ru(CO)4 and Ru(CO)3,a singlet structure with C2v symmetry and a Cs bent Tshaped structure are the lowest-energy structures,respectively.The global minimum for the Ru2(CO)9 is a singly bridged(CO)4Ru(μ-CO)Ru(CO)4 structure.A triply bridged Ru2(CO)6(μ-CO)3 structure analogous to the known Fe2(CO)9 structure is predicted to lie very close in energy to the global minimum.For Ru2(CO)8,the doubly bridged C2 structure is predicted to be the global minimum.For the lowest-energy structures of M2(CO)n(M=Fe,Ru,Os,n=9,8),it is found that both iron and ruthenium are favored to form structures containing more bridging carbonyl groups,while osmium prefers to have structures with less bridging carbonyl groups.The study of dissociation energy shows that the dissociation of Ru2(CO)9 into the mononuclear fragments Ru(CO)5+Ru(CO)4 is a less energetically demanding process than the dissociation of one carbonyl group from Ru2(CO)9 to give Ru2(CO)8.
基金supported by National Natural Science Foundation of China(grant numbers:32202198)。
文摘The inhibition capacity of bound-polyphenol rich insoluble dietary fiber(BP-IDF)from highland barley to carbonyl compounds was studied during in vitro gastrointestinal(GI)digestion.More than 97%of fiber-bound polyphenols were still presented in highland barley BP-IDF(HBBP-IDF)after GI digestion.The fiber-bound polyphenols in HBBP-IDF effectively inhibit carbonyls when simultaneously digested with cookies and French fries and exhibited more pronounced effect during gastric digestion stage,with inhibition of 63.4%for methylglyoxal,54.3%for glyoxal,47.6%for malondialdehyde and 42.4%for 4-hydroxy-2-nonenel,respectively.These findings suggest that HBBP-IDF could be use as functional ingredients able to inhibit the formation of carbonyls during digestion process and maintain healthful digestive tract environment.
基金This work was supported by the National Natural Science Foundation of China （Grant No. 40905069）, China EPA Charity Special Fund （No.201009032）, and State Key Laboratory Special Fund （No. 13Z05ESPCP）.
文摘Volatile organic compounds （VOCs） and carbonyl compounds were measured both indoors and outdoors in 50 residences of Beijing in heating （December, 2011） and non-heating seasons （April/May, 2012）. SUMMA canisters for VOCs and diffusive samplers for carbonyl compounds were deployed for 24 h at each site, and 94 compounds were quantified. Formaldehyde, acetone and acetaldehyde were the most abundant carbonyl compounds both indoors and outdoors with indoor median concentrations being 32.1, 21.7 and 15.3 μg·m-3, respec- tively. Ethane （17.6 μg·m-3）, toluene （14.4 μg·m-3）, pro- pane （11.2 μg·m-3）, ethene （8.40 μg·m-3）, n-butane （6.87 μg·m-3）, and benzene （5.95 μg·m-3） showed the high median concentrations in indoor air. Dichloromethane, p- dichlorobenzene （p-DCB） and toluene exhibited extremely high levels in some residences, which were related with a number of indoor emission sources. Moreover, isoprene, p- dichlorobenzene and carbonyls showed median indoor/ outdoor （I/O） ratios larger than 3, indicating their indoor sources were prevailing. Chlorinated compounds like CFCs were mainly from outdoor sources for their I/O ratios being less than 1. In addition, indoor concentrations between two sampling seasons varied with different compounds. Carbonyl compounds and some chlorinated compounds had higher concentrations in the non-heating season, while alkanes, alkenes, aromatic compounds showed an increase in the heating season. Indoor concentration of VOCs and carbonyls were influenced by locations, interior decorations and indoor activities, however the specific sources for indoor VOCs and carbonyls could not be easily identified. The findings obtained in this study would significantly enhance our understandings on the prevalent and abundant species of VOCs as well as their concentrations and sources in Beijing residences.
基金financially supported by the Shandong Provincial Natural Science Foundation(Nos.ZR2021JQ16,ZR2019YQ19and ZR2019BEM018)the Project of Shandong Province Higher Educational Science and Technology Program(No.2019KJA026)+1 种基金the National Natural Science Foundation of China(Nos.51403113 and 52072193)the Shandong Provincial College Students'Innovative Entrepreneurial Training(No.S202111065214).
文摘Aromatic carbonyls have evoked sustained attention in the field of room-temperature phosphorescence(RTP).The introduction of carbonyl groups is a general way to achieve RTP for their effective intersystem crossing(ISC)by improving spin-orbit coupling(SOC).With further molecular design and processing strategies,aromatic carbonyls materials with multi-functional and high efficiency ultralong organic phosphorescence(UOP)can be obtained.This review summarizes the mechanism of aromatic carbonyls with UOP in pure aromatic carbonyls and their multi-component systems.Some detailed strategies for improving UOP performance are further introduced.The summary and outlook are presented to expound on the advances and lack of aromatic carbonyls.Further development directions and requirements are also put forward.
基金supported by the National Natural Science Foundation of China(Nos.82241088 and 82203996)the China Postdoctoral Science Foundation(Nos.2022T150230 and 2021M691131).
文摘Arsenic-related oxidative stress and resultant diseases have attracted global concern,while longitudinal studies are scarce.To assess the relationship between arsenic exposure and systemic oxidative damage,we performed two repeatedmeasures among 5236 observations(4067 participants)in theWuhan-Zhuhai cohort at the baseline and follow-up after 3 years.Urinary total arsenic,biomarkers of DNA oxidative damage(8-hydroxy-2-deoxyguanosine(8-OHdG)),lipid peroxidation(8-isoprostaglandin F2alpha(8-isoPGF2α)),and protein oxidative damage(protein carbonyls(PCO))were detected for all observations.Here we used linearmixed models to estimate the cross-sectional and longitudinal associations between arsenic exposure and oxidative damage.Exposure-response curves were constructed by utilizing the generalized additive mixed models with thin plate regressions.After adjusting for potential confounders,arsenic level was significantly and positively related to the levels of global oxidative damage and their annual increased rates in dose-response manners.In cross-sectional analyses,each 1%increase in arsenic levelwas associated with a 0.406%(95%confidence interval(CI):0.379%to 0.433%),0.360%(0.301%to 0.420%),and 0.079%(0.055%to 0.103%)increase in 8-isoPGF2α,8-OHdG,and PCO,respectively.More importantly,arsenic was further found to be associated with increased annual change rates of 8-isoPGF2α(β:0.147;95%CI:0.130 to 0.164),8-OHdG(0.155;0.118 to 0.192),and PCO(0.050;0.035 to 0.064)in the longitudinal analyses.Our study suggested that arsenic exposurewas not only positively related with global oxidative damage to lipid,DNA,and protein in cross-sectional analyses,but also associated with annual increased rates of these biomarkers in dose-dependent manners.
基金supported by the National Natural Science Foundation of China(Nos.42077198 and 22206023)Liaoning Revitalization Talents Program(No.XLYC1907185)+1 种基金Liaoning Science and Technology Joint Project(No.2023-MSBA-109)the Fundamental Research Funds for the Central Universities(Nos.N2325019 and N2325034).
文摘The photochemical conversion of SO_(2) to sulfates on 4-(benzoyl)benzoic acid(4-BBA)was investigated deeply in the presence of anionic and cationic surfactants.The types of surfactants determined their effect behaviors,and cationic surfactants can significantly enhance the SO_(2) oxidation on 4-BBA under irradiation,as shown by larger SO_(2) uptake coefficients and sulfate production.Hydrophilic moieties in cationic surfactants have a greater enhancement effect on the photochemical conversion of SO_(2) to sulfates than the corresponding hydrophobic moieties.Cationic surfactants obviously increased the accumulation of H_(2)O on the surface,which was proved to be the main factor influencing the SO_(2) uptake and the sulfate formation on 4-BBA.SO_(2) lifetime and sulfate formation rate in the mixture system of photosensitive substances with surfactants were evaluated to be 2.25 days and 0.09μg/(m^(3)·h),respectively.
文摘Chiral carbonyl compounds frequently occur in natural products and pharmaceuticals. Additionally, they serve as important intermediates in organic synthesis. Transition metal-catalyzed asymmetric carbonylative cross-coupling reactions are among the most straightforward and effective methods for synthesizing chiral carbonyl compounds, including esters, amides, and ketones. The advances in asymmetric carbonylative cross-coupling reactions using various O-, N-, C-, and S-containing nucleophiles or electrophiles over the past decade are summarized.
文摘Polyhydroxyalkanoate(PHA),a well-known biodegradable polymer,featuresβ-lactones as its monomers,which can be selectively synthesized through ring-expansion carbonylation of epoxides using well-defined[Lewis acid]^(+)[Co(CO)_(4)]^(-)catalysts.However,the decomposition of[Co(CO)_(4)]^(-)species at temperatures exceeding 80℃presents a hurdle for the development of commercially viable processes under high-temperature reaction conditions to reduce reaction time.Drawing insights from stable{(acyl)Co(CO)n}intermediates involved in historical HCo(CO)_(4)-catalyzed hydroformylation processes,we sought to the high-temperature catalytic activity of epoxide ring-expansion carbonylation.The developed catalyst system,[(acetyl)Co(CO)_(2)dppp]and[(TPP)CrCl],exhibited exceptional catalytic performance with an unprecedented initial turnover frequency of 4700 h^(-1)at 100℃and a turnover numbers of 93000.Notably,the catalyst displayed outstanding stability,operating at 80℃for 168 h while selectively generatingβ-lactones.
基金supported by National Key R&D Program of China(No.2023YFA1507500)the International Partnership Program of Chinese Academy of Sciences(No.028GJHZ2023045FN)。
文摘The amide moiety plays an important role as a powerful bioactive backbone,and as the synthetic chemistry community moves toward more sp^(3)-rich scaffolds,alkyl halides have become the feedstock of choice for obtaining carbonylation products.With the development of photoredox catalysis,several aminocarbonylation systems for alkyl halides were developed which usually require transition metal catalysis.Considering the demands for green sustainable chemical synthesis,here we report a metal-free,exogenous catalyst-free aminocarbonylation reaction of alkyl iodides under atmospheric pressure of carbon monoxide.Through a combination of EDA and XAT strategies,the reaction occurs efficiently under only light irradiation at room temperature.
基金supported by the National Natural Science Foundation of China(No.42077120)the Special Foundation for Taishan Scholar of Shandong Province(2023)the Project of Talent Introduction and Education Program of Youth Innovation Teams in Universities of Shandong Province(No.2021-05).
文摘Microplastics(MPs) are an emerging environmental pollutant and have penetrated the most remote and primitive areas. MPs degradation has received widespread attention. Manganese(Mn) is a highly reactive metal element in the environment, yet its contribution to MPs degradation remains unclear. Herein,we simulated the aging of polyethylene MPs with Mn(Ⅱ) under aqueous conditions at pH 5 and 8 for720 days. Mn greatly promoted the MPs degradation, and the average particle sizes of polyethylene MPs were reduced from 9.2 μm to 5.9 μm after aging at pH 5 under light irradiation for 720 days. Plenty of oxygen-containing groups were generated on the MPs surfaces, and the carbonyl index remarkably increased, reaching four times that of the control without adding Mn. Mechanistically, the adsorbed Mn(Ⅱ)on the MPs surfaces were primarily oxidized to high-valence Mn(Ⅲ/Ⅳ) profited from the photoproduced radicals, followed by the MPs oxidation via Mn(Ⅲ/Ⅳ), which were reduced to regenerate Mn(Ⅱ), initiating a new redox cycling. During the degradation, dissolved organic matter was continuously released, mainly including bisphenol A and phthalic acid esters. Mn acts as a catalyst to accelerate the MPs degradation by redox cycling. Our results provide a new insight into the mechanisms of abiotic degradation of MPs in aqueous environments.
基金the financial support from National Key R&D Program of China(No.2023YFA1507500)DICP。
文摘Carboxylic acid derivatives withα-quaternary carbon center are one of the most ubiquitous moieties in synthetic and medicinal chemistry.Hence,novel and efficient synthetic methods towards carboxylic acid derivatives withα-quaternary carbon remain in high demand.However,most of the precursors of these complex compounds are not easy to prepare.Reported herein is a carbonylative five-component synthesis of amides and esters withα-quaternary carbon center enabled by palladium catalysis from abundant acrylonitrile,carbon monoxide,fluoroalkyl halides,and nucleophiles.Diverse amides and esters withα-quaternary carbon which contain difluoromethyl or perfluoroalkyl moiety were prepared in good to excellent yields,providing an efficient synthetic platform for sequential transformations.
文摘Protein damage repair and prevention are important objectives in skin care industry.Skin protein damage or modifications such as glycation,carbonylation or oxidation,have a significant impact on its function,therefore directly influencing various skin functions or properties including skin appearance.However,there is a lack of comprehensive methods to visualize and assess the protein damage.In this article,we present a three-channel imaging approach to simultaneously visualize and quantitatively evaluate protein oxidation,protein glycation and carbonylation in a full-thickness skin model.We successfully visualized and quantified the impact of the multiple stimuli(ultraviolet radiation A(UVA)and/or methylglyoxal)as well as treatment effect of positive control(vitamins C and E)with this method.Our findings indicate that multiple stimuli exhibit synergistic effects on protein damage.Furthermore,we evaluated a unique combination of skin care ingredients which demonstrated an excellent efficacy in resisting protein damage.Further research revealed that three ingredients of the combination upregulate autophagy in cells,which may contribute to remove damaged proteins and maintain protein quality homeostasis.This method provides a holistic assessment of protein damages and can be employed to evaluate the impact of various stimuli or to assess the efficacy of skin care ingredients in mitigating such damage.
基金the financial support from the National Natural Science Foundation of China(Nos.21801025,22225106)Natural Science Foundation of Sichuan Province(No.2022NSFSC0200)Sichuan Science and Technology Program(No.MZGC20230100)。
文摘Herein,we report an iron-promoted carbonylation-rearrangement ofα-aminoaryl-tethered alkylidene cyclopropanes with CO_(2)to generate quinolinofuran derivatives.A variety of quinolinofuran derivatives are obtained in moderate to excellent yields,and two promising luminescent material molecules have been synthesized using the developed method.The Lewis acid Fe Cl_(3)was introduced into this reaction,which effectively promoted the ring opening and rearrangement of cyclopropanes.This reaction features a broad substrate scope,satisfactory functional group tolerance,facile scalability,and easy derivatization of the products.
