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Photoinduced Radical-Ionic Transfer of Various chlorofluorocarbons to Alkenes from Oxime-Based Surrogates

CCS Chemistry 2024年第5期6卷 1222-1230页

作者： Jinghui Zhang Muliang Zhang Martin Oestreich Institut für Chemie Technische Universität Berlin10623 Berlin Hefei National Laboratory for Physical Sciences at the Microscale and Department of Chemistry University of Science and Technology of ChinaHefei 230026

Functional-group-transfer strategies that avoid the use of unsustainable chemicals are attractive for the development of green ***(CFCs)not only contribute to the depletion of the stratospheric ozone layer,but their gaseous nature also poses a serious threat in scientific ***,the design of effective and sustainable alternatives to CFCs is highly ***,a practical CFC transfer platform for the addition of both a fluoroalkyl group and a chlorine substituent across alkenes by a photomediated redox-neutral manifold using bench-stable and easy-to-handle oxime-based surrogates is *** distinct reactivity of these tunable reagents allows for their single-electron reduction to trigger fragmentation driven by benzonitrile formation and loss of carbon *** other fragments released in that step,namely an electrophilic fluoroalkyl radical and a nucleophilic chloride anion,are subsequently transferred onto alkenes by a radical-ionic mechanism to deliver the desired chlorofluorocarbon products.

关键词： alkenes chlorofluorocarbons functionalgroup transfer radical-ionic crossover photoredox catalysis

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Robust perfluorinated porous organic networks: Succinct synthetic strategy and application in chlorofluorocarbons adsorption

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Nano Research 2021年第9期14卷 3282-3287页

作者： Yali Luo Zhenzhen Yang Xian Suo Hao Chen Tao Wang Ziqian Wang Yunfei Liu Yinong Lyu llja Popovs Sheng Dai College of Materials Science and Engineering Jiangsu National Synergetic Innovation Center for Advanced Materials(SICAM)Jiangsu Collaborative Innovation Center for Advanced Inorganic Function CompositesNanjing Tech UniversityNanjing 211816China Department of Chemistry The University of TennesseeKnoxvilleTN 37996USA Chemical Sciences Division Oak Ridge National LaboratoryOak RidgeTN 37831USA

Fluorinated porous organic networks(F-PONs)have demonstrated unique properties and applications,but approaches capable of affording F-PONs with high fluorine content and robust nanoporous architecture under metal-free and easy handling conditions are still rarely ***,using polydivinylbenzene(PDVB)as an easily available precursor,a novel and straightforward approach was developed to afford F-PONs via a dehydrative Friedel-Crafts reaction using perfluorinated benzylic alcohols as the cross-linking agent promoted by Bronsted acid(trifluoromethanesulfonic acid).The afforded material(F-PDVB)featured high fluorine content(22 at.%),large surface area(771 m^(2)·g^(-1)),and good chemical/thermal stability,rendering them as promising candidates for the adsorption of CO_(2),hydrocarbons,fluorocarbons,and chlorofluorocarbons,with weight capacities up to 520 wt.%being *** simple methodology can be extended to fabricate fluorinated hyper-crosslinked polymers(F-HCPs)from rigid aromatic *** progress made in this work will open new opportunities to further expand the involvement of fluorinated materials in large scale applications.

关键词： fluorinated porous organic networks Friedel-Crafts reaction hyper-crosslinked polymers chlorofluorocarbons

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Determination of chlorofluorocarbons in Groundwater by Purge and Trap and Secondary Cold Trap Coupled with Gas Chromatography/Mass Spectrometry

Determination of Chlorofluorocarbons in Groundwater by Purge...

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中国科学院地质与地球物理研究所2013年度（第13届）...

作者： ZHANG Jiang-Yi LI Guo-Min GUO Wei Key Laboratory of Engineering Geomechanics Institute of Geology and GeophysicsChinese Academy of Sciences State Key Laboratory of Biogeology and Environmental Geology School of Environmental StudiesChina University of Geosciences

A method was established to determine the chlorofluorocarbons(CFCs) in groundwater by purge and trap and secondary cold trap coupled with gas chromatography/mass spectrometry(GC-MS).The groundwater samples were processed with absorption/thermal desorption/cold trap/thermal desorption,and GC-MS was used for quantitative and confirmatory *** results showed that the relative standard deviations of chlorotrifluoromethane(CFC-11),dichlorodifluoromethane(CFC-12) and 1,1,2-trichlorotrifluoromethane(CFC-113) were 1.1%,0.9%and 1.5%.The method linearity range of the CFC-11,CFC-12 and CFC-113 were 0.09×10-3.0×10 M,0.04×10-3.0×10M and 4.0×10-4.0×10M,*** correlation coefficients were greater than *** detection limit of CFC-11,CFC-12,CFC-113 were 4.4×10M,1.6×10M and 5.36×10M,*** average recovery of the spiked samples was 95.4%-102.0%.The method was quick,sensitive,easy and feasible for the detection of CFCs in *** to the analysis results,the apparent age of groundwater can be calculated.

关键词： chlorofluorocarbons Groundwater Gas chromatography/mass spectrometry Purge and trap

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The Effect of Diapycnal Mixing on the Ventilation and CFC-11 Uptake in the Southern Ocean

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Advances in Atmospheric Sciences 2004年第5期21卷 755-766页

作者： Helge DRANGE Nansen Environmental and Remote Sensing Center Bergen Norway Nansen-Zhu International Research Centre Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029Bjerknes Centre for Climate Research Bergen Norway Geophysical Institute University of Bergen Bergen Norway

The Miami Isopycnic Coordinate Ocean Model (MICOM) is used to investigate the effect of diapycnal mixing on the oceanic uptake of CFC-11 and the ventilation of the surface waters in the Southern Ocean (south of 45°S). Three model experiments are performed: one with a diapycnal mixing coefficientK d (m2 s?1) of 2 × 10?7/N (Expt. 1), one withK d = 0 (Expt. 2), and one withK d = 5 × 10?8/N (Expt. 3),N (s?1) is the Brunt-V?is?l? frequency. The model simulations indicate that the observed vertical distribution of CFC-11 along 88°W (prime meridian at 0°E) in the Southern Ocean is caused by local ventilation of the surface waters and westward-directed (eastward-directed) isopycnic transport and mixing from deeply ventilated waters in the Weddell Sea region. It is found that at the end of 1997, the simulated net ocean uptake of CFC-11 in Expt. 2 is 25% below that of Expt. 1. The decreased uptake of CFC-11 in the Southern Ocean accounts for 80% of this difference. Furthermore, Expts. 2 and 3 yield far more realistic vertical distributions of the ventilated CFC-waters than Expt. 1. The experiments clearly highlight the sensitivity of the Southern Ocean surface water ventilation to the distribution and thickness of the simulated mixed layer. It is argued that inclusion of CFCs in coupled climate models could be used as a test-bed for evaluating the decadal-scale ocean uptake of heat and CO2.

关键词： chlorofluorocarbons CFC-11 diapycnal mixing ocean modelling ocean ventilation Southern Ocean transient tracers

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AIR CONDITIONING REFRIGERANTS AND OZONE PROTECTION

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Journal of China Textile University(English Edition) 1995年第1期12卷 56-60页

作者：周亚素华征宇

Until recently, CFC-11 and CFC-12 were the most widely used refrigerant gases in air conditioning systems. Environmental agencies around the world, however, have specifical concern for these gases as a direct cause of the depletion of the Earth’s ozone layer. Consequently, the world’s industrial nations are taking concerted action to decrease the use of CFCs, calling for attention of the engineers and designers involved in the manufacture and application of refrigeration systems for air conditioning. This paper analyses the available alternatives of CFCs in the industry and examines the problem found in process application.

关键词： air conditioning refeigerant chlorofluorocarbons ozone layer alternative refrigerant.

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Depletion of the Ozone Layer and Its Consequences: A Review

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American Journal of Plant Sciences 2013年第10期4卷 1990-1997页

作者： Anjali Aggarwal Reeta Kumari Neeti Mehla Deepali Rishi Pal Singh Sonal Bhatnagar Kameshwar Sharma Kuldeep Sharma Vashishtha Amit Brijesh Rathi Department of Biochemistry Sri Venkateswara College University of Delhi New Delhi India Department of Botany Deshbandhu College University of Delhi New Delhi India Department of Botany Sri Venkateswara College University of Delhi New Delhi India Department of Botany Uni- versity of Delhi New Delhi India. Department of Chemistry Sri Venkates- wara College University of Delhi New Delhi India

Ozone (O3) is a stratospheric layer that plays important role in providing support to humans for their survival. It is an essential factor for many global, biological and environmental phenomena. The ultra-violet (UV) rays emitted from sun are captured by ozone and thereby provide a stable ontological structure in the biosphere. Various anthropogenic activities such as emissions of CFCs, HCFCs and other organo-halogens lead to the depletion of ozone. The ozone depletion resulted in secondary production of an ozone layer near the ground (terrestrial ozone layer), which is responsible for adverse effects on plants, humans and environment with increased number of bronchial diseases in humans. The mutations caused by UV rays result in variation in morphogenic traits of plants which ultimately decreases crop productivity. However, UV radiation is required in optimum intensity for both plants and animals. This review takes into an account the wide ranging effects of ozone depletion with a majority of them being detrimental to the plant system.

关键词： Ozone Depletion Ultra-Violet Radiation chlorofluorocarbons Plants Ecosystem

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