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Photochemical Production of Methyl Halides with Guaiacol as the Precursor
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作者 YANG Fan ZHANG Yan +2 位作者 WU Guanyu HE Zhen YANG Guipeng 《Journal of Ocean University of China》 SCIE CAS CSCD 2024年第5期1275-1286,共12页
Methyl halides are crucial trace greenhouse gases in the atmosphere,playing a significant role in global climate change and the atmospheric environment.This study investigated the photochemical production of methyl ha... Methyl halides are crucial trace greenhouse gases in the atmosphere,playing a significant role in global climate change and the atmospheric environment.This study investigated the photochemical production of methyl halides in an artificial seawater system using guaiacol as a precursor through laboratory simulation experiments.The influences of various environmental factors,including illumination time,radiation wavebands,illumination intensity,concentrations of guaiacol and halide ions(X^(-)),Fe^(3+),salinity,dissolved oxygen(DO),and pH value on the photochemical production of methyl halides were examined.We demonstrated that increased illumination intensity and duration promote the photochemical production of methyl halides,with a notable enhancement under UV-B radiation.Guaiacol and halide ions were identified as key precursors,and their high concentrations facilitated the formation of methyl halides.Additionally,different types of halide ions exhibited a competitive relationship in producing methyl halides.The study found that an increase in pH inhibited the photochemical formation of CH_(3)I due to the reaction between OH^(-)and·CH_(3).Dissolved oxygen was found to inhibit the photochemical formation of CH3I while promoting the formation of CH_(3)Cl.Conversely,an appropriate concentration of Fe^(3+)enhanced the photochemical production of methyl halides.Field observations indicated a high photochemical production of methyl halides in the natural waters near Qingdao’s coastal area,likely due to the high concentration of dissolved organic matter(DOM),which supports photochemical reactions.Furthermore,the photochemical production of methyl halides in natural seawater was significantly higher than in dark conditions,underscoring the importance of illumination in promoting these photochemical processes in seawater. 展开更多
关键词 methyl halides photochemical production dissolved organic matter GUAIACOL
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Light emission from multiple self-trapped excitons in one-dimensional Ag-based ternary halides
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作者 Jiahao Xie Zewei Li +1 位作者 Shengqiao Wang Lijun Zhang 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第11期62-69,共8页
Ternary metal halides based on Cu(I)and Ag(I)have attracted intensive attention in optoelectronic applications due to their excellent luminescent properties,low toxicity,and robust stability.While the self-trapped exc... Ternary metal halides based on Cu(I)and Ag(I)have attracted intensive attention in optoelectronic applications due to their excellent luminescent properties,low toxicity,and robust stability.While the self-trapped excitons(STEs)emission mechanisms of Cu(I)halides are well understood,the STEs in Ag(I)halides remain less thoroughly explored.This study explores the STE emission efficiency within the A_(2)AgX_(3)(A=Rb,Cs;X=Cl,Br,I)system by identifying three distinct STE states in each material and calculating their configuration coordinate diagrams.We find that the STE emission efficiency in this system is mainly determined by STE stability and influenced by self-trapping and quenching barriers.Moreover,we investigate the impact of structural compactness on emission efficiency and find that the excessive electron–phonon coupling in this system can be reduced by increasing the structural compactness.The atomic packing factor is identified as a low-cost and effective descriptor for predicting STE emission efficiency in both Cs_(2)AgX_(3) and Rb_(2)AgX_(3) systems.These findings can deepen our understanding of STE behavior in metal halide materials and offer valuable insights for the design of efficient STE luminescent materials.The datasets presented in this paper are openly available in Science Data Bank at https://doi.org/10.57760/sciencedb.12094. 展开更多
关键词 self-trapped exciton Ag-based ternary halides configuration coordinate diagrams emission efficiency
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Luminescence regulation of Sb^(3+)in 0D hybrid metal halides by hydrogen bond network for optical anti-counterfeiting
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作者 Dehai Liang Saif M.H.Qaid +5 位作者 Xin Yang Shuangyi Zhao Binbin Luo Wensi Cai Qingkai Qian Zhigang Zang 《Opto-Electronic Advances》 SCIE EI CAS CSCD 2024年第3期15-25,共11页
The Sb^(3+) doping strategy has been proven to be an effective way to regulate the band gap and improve the photophysical properties of organic-inorganic hybrid metal halides(OIHMHs).However,the emission of Sb^(3+) io... The Sb^(3+) doping strategy has been proven to be an effective way to regulate the band gap and improve the photophysical properties of organic-inorganic hybrid metal halides(OIHMHs).However,the emission of Sb^(3+) ions in OIHMHs is primarily confined to the low energy region,resulting in yellow or red emissions.To date,there are few reports about green emission of Sb^(3+)-doped OIHMHs.Here,we present a novel approach for regulating the luminescence of Sb^(3+) ions in 0D C_(10)H_(2)_(2)N_(6)InCl_(7)·H_(2)O via hydrogen bond network,in which water molecules act as agents for hydrogen bonding.Sb^(3+)-doped C_(10)H_(2)2N_(6)InCl_(7)·H_(2)O shows a broadband green emission peaking at 540 nm and a high photoluminescence quantum yield(PLQY)of 80%.It is found that the intense green emission stems from the radiative recombination of the self-trapped excitons(STEs).Upon removal of water molecules with heat,C_(10)H_(2)_(2)N_(6)In_(1-x)Sb_(x)Cl_(7) generates yellow emis-sion,attributed to the breaking of the hydrogen bond network and large structural distortions of excited state.Once water molecules are adsorbed by C_(10)H_(2)_(2)N_(6)In_(1-x)Sb_(x)Cl_(7),it can subsequently emit green light.This water-induced reversible emission switching is successfully used for optical security and information encryption.Our findings expand the under-standing of how the local coordination structure influences the photophysical mechanism in Sb^(3+)-doped metal halides and provide a novel method to control the STEs emission. 展开更多
关键词 indium-based halides Sb^(3+)doping hydrogen bonding network optical anti-counterfeiting
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Stimuli-responsive photoluminescent copper(Ⅰ) halides for scintillation, anticounterfeiting, and light-emitting diode applications
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作者 Dilruba A.Popy Yashpal Singh +6 位作者 Yauhen Tratsiak Abby M.Cardoza John M.Lane Luis Stand Mariya Zhuravleva Neeraj Rai Bayram Saparov 《Aggregate》 EI CAS 2024年第5期465-480,共16页
Highly sensitive stimuli-responsive luminescent materials are crucial for appli-cations in optical sensing,security,and anticounterfeiting.Here,we report two zero-dimensional(0D)copper(I)halides,(TEP)_(2)Cu_(2)Br_(4),... Highly sensitive stimuli-responsive luminescent materials are crucial for appli-cations in optical sensing,security,and anticounterfeiting.Here,we report two zero-dimensional(0D)copper(I)halides,(TEP)_(2)Cu_(2)Br_(4),(TEP)_(2)Cu_(4)Br_(6),and 1D(TEP)_(3)Ag_(6)Br_(9),which are comprised of isolated[Cu_(2)Br_(4)]^(2-),[Cu_(4)Br_(6)]^(2-),and[Ag_(6)Br_(9)]3-polyanions,respectively,separated by TEP^(+)(tetraethylphosphonium[TEP])cations.(TEP)_(2)Cu_(2)Br_(4) and(TEP)_(2)Cu_(4)Br_(6) demonstrate greenish-white and orange-red emissions,respectively,with near unity photoluminescence quantum yields,while(TEP)_(3)Ag_(6)Br_(9) is a poor light emitter.Optical spectroscopy mea-surements and density-functional theory calculations reveal that photoemissions of these compounds originate from self-trapped excitons due to the excited-state distor-tions in the copper(I)halide units.Crystals of Cu(I)halides are radioluminescence active at room temperature under both X-andγ-rays exposure.The light yields up to 15,800 ph/MeV under 662 keVγ-rays of ^(137)Cs suggesting their potential for scintillation applications.Remarkably,(TEP)_(2)Cu_(2)Br_(4) and(TEP)_(2)Cu_(4)Br_(6) are inter-convertible through chemical stimuli or reverse crystallization.In addition,both compounds demonstrate luminescence on-off switching upon thermal stimuli.The sensitivity of(TEP)_(2)Cu_(2)Br_(4) and(TEP)_(2)Cu_(4)Br_(6) to the chemical and thermal stimuli coupled with their ultrabright emission allows their consideration for applications such as solid-state lighting,sensing,information storage,and anticounterfeiting. 展开更多
关键词 0D copper(I)halides anticounterfeiting efficient photoluminescence SCINTILLATORS solid-state lighting
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Glass-compatible and self-powered temperature alarm system by temperature-responsive organic manganese halides via backward energy transfer process
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作者 Pengfei Xia Fan Liu +4 位作者 Yuru Duan Xuefang Hu Changgui Lu Shuhong Xu Chunlei Wang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第3期188-194,I0006,共8页
A pioneering glass-compatible transparent temperature alarm system self-powered by luminescent solar concentrators(LSCs) is reported.Single green-emitted organic manganese halides(OMHs) of PEA_(2)MnBr_(2)I_(2),which h... A pioneering glass-compatible transparent temperature alarm system self-powered by luminescent solar concentrators(LSCs) is reported.Single green-emitted organic manganese halides(OMHs) of PEA_(2)MnBr_(2)I_(2),which has a unique temperature-dependent backward energy transfer process from selftrapped state to^(4)T_(1)energy level of Mn,is used for triggering the temperature alarm.The LSC with redemitted CsPbI_(3)perovskite-polymer composite films on the glass substrate is used for power supply.The spectrally separated nature between the green-emitted OMHs for temperature alarm and red-emitted CsPbI3in LSC for power supply allows for probing the signal light of temperature-responsive OMHs without the interference of LSCs,making it possible to calibrate the temperature visually just by a self-powered brightness detection circuit with LED indicators.Taking advantage of LSC without hot spot effects plaguing the solar cells,as-prepared temperature alarm system can operate well on both sunny and cloudy day. 展开更多
关键词 Luminescent solar concentrators Organic manganese halides Perovskite-polymer compositefilms Self-powered temperature alarm system Backward energy transfer process
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Stable yellow light emission from lead-free copper halides single crystals for visible light communication
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作者 Baiqian Wang Yuru Tang +6 位作者 Xin Yang Wensi Cai Ru Li Wen Ma Shuangyi Zhao Chen Chen Zhigang Zang 《Nano Materials Science》 EI CAS CSCD 2023年第1期78-85,共8页
Yellow light-emitting diodes(LEDs) as soft light have attracted abundant attention in lithography room, museum and art gallery. However, the development of efficient yellow LEDs lags behind green and blue LEDs, and th... Yellow light-emitting diodes(LEDs) as soft light have attracted abundant attention in lithography room, museum and art gallery. However, the development of efficient yellow LEDs lags behind green and blue LEDs, and the available perovskites yellow LEDs suffer from the instability. Herein, a pressure-assisted cooling method is proposed to grow lead-free CsCu2I3single crystals, which possess uniform surface morphology and enhanced photoluminescence quantum yield(PLQY) stability, with only 10% PLQY losses after being stored in air after 5000 h.Then, the single crystals used for yellow LEDs without encapsulation exhibit a decent Correlated Color Temperature(CCT) of 4290 K, a Commission Internationale de l’Eclairage(CIE) coordinate of(0.38, 0.41), and an excellent 570-h operating stability under heating temperature of 100°C. Finally, the yellow LEDs facilitate the application in wireless visible light communication(VLC), which show a-3 dB bandwidth of 21.5 MHz and a high achievable data rate of 219.2 Mbps by using orthogonal frequency division multiplexing(OFDM) modulation with adaptive bit loading. The present work not only promotes the development of lead-free single crystals, but also inspires the potential of CsCu2I3in the field of yellow illumination and wireless VLC. 展开更多
关键词 Lead-free copper halides Single crystals Yellow light-emitting diodes Visible light communication(VLC)
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Controlled Radical Polymerization of Styrene in the Presence of Different Copper Complexes and Organic Halides 被引量:2
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作者 CHENG Guang-lou HU Chun-pu YING Sheng-kang 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 1999年第4期358-363,共6页
The polymerization behaviors of Styrene (St) in the presence of CuX/L [X=Cl or Br; L= 2,2 bipyridine (bpy), 1,10 phenanthroline (phen) or 4,7 diphenyl 1,10 phenanthroline (DPP) ] and R X (R=trichloromethyl, benz... The polymerization behaviors of Styrene (St) in the presence of CuX/L [X=Cl or Br; L= 2,2 bipyridine (bpy), 1,10 phenanthroline (phen) or 4,7 diphenyl 1,10 phenanthroline (DPP) ] and R X (R=trichloromethyl, benzyl or allyl; X=Cl or Br) have been studied and examined. In a CuCl/bpy/RCl/St system, a bimodal GPC peak at the early stage of polymerization was observed, and a concept of multi active species was proposed to explain this phenomenon. In a CuCl/phen (DPP)/RCl/St system, the \%M\%\-n of polystyrene (PS) increased linearly with St conversion and ln[M] o/[M] also increased linearly with time, indicating the living nature of this system. Furthermore, the stability of the propagating active species in a CuBr/phen/RBr/St system is higher than that in the CuBr/phen/RBr/St system. 展开更多
关键词 ATRP 'Living'/controlled radical polymerization 1 10-PHENANTHROLINE 4 7-Diphenyl-1 10-phenanthroline Cuprous halides STYRENE
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An Efficient and Novel Synthesis of Carbamate Esters from the Coupling of Amines, Halides and Carbon Dioxide in the Presence of Basic Resin 被引量:1
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作者 Devdutt CHATURVEDI Nisha MISHRA Virendra MISHRA 《Chinese Chemical Letters》 SCIE CAS CSCD 2006年第10期1309-1312,共4页
A convenient, efficient, one-pot, novel process has been developed for the synthesis of carbamates from corresponding alkyl halides and amines using basic resin/CO2 system.
关键词 Basic resin (Ambedite IRA 400) alkyl halides carbon dioxide AMINES carbamates.
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PHOTOINDUCED S_(RN)1 REACTIONS OF ARYL HALIDES WITH CARBAZOLYL NITROGEN ANION 被引量:1
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作者 Chi Zhong XIA,Zhao Bin CHEN,Zhao ZHANG Department of Chemistry,Shanxi University,Taiyuan,Shanxi 030006 《Chinese Chemical Letters》 SCIE CAS CSCD 1991年第2期131-132,共2页
The photoinduced reactions of aryl halides with carbazolyl nitrogen anion,in dimethyl sulfoxide,yield the corresponding N-arylated products.These reactions are suggested in terms of the S;Nl mechaism of nucleophilic s... The photoinduced reactions of aryl halides with carbazolyl nitrogen anion,in dimethyl sulfoxide,yield the corresponding N-arylated products.These reactions are suggested in terms of the S;Nl mechaism of nucleophilic substitution. 展开更多
关键词 KBR IR CM RN)1 REACTIONS OF ARYL halides WITH CARBAZOLYL NITROGEN ANION PHOTOINDUCED S
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Methane oxidative carbonylation catalyzed by rhodium chalcogen halides over carbon supports 被引量:1
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作者 G.R.Kosmambetoval P.E.Strizhak +4 位作者 V.I.Gritsenko S.V.Volkov L.B.Kharkova O.G.Yanko O.M.Korduban 《Journal of Natural Gas Chemistry》 EI CAS CSCD 2008年第1期1-7,共7页
Gas phase carbonylation of methane is studied in the presence of molecular oxygen over pure carbon carriers and carbon supported rhodium chalcogen halides. Activated carbons and fullerene blacks have been used as carb... Gas phase carbonylation of methane is studied in the presence of molecular oxygen over pure carbon carriers and carbon supported rhodium chalcogen halides. Activated carbons and fullerene blacks have been used as carbon supports. XPS and IR-spectroscopy data show the formation of rhodium chalcogen halides in solids prepared by different methods. We have found that the productivity of acetic acid by carbon supported rhodium chalcogen halides depends strongly on the carbon carrier and the method of the catalyst preparation. Namely, the catalyst with highest productivity for the acetic acid is prepared by synthesizing the rhodium chalcogen halide over the carbon support followed by thermal destruction. We have also found that rhodium chalcogen halides over activated carbons are more active compared with fullerene supported catalysts. 展开更多
关键词 CATALYSTS methane oxidative carbonylation rhodium chalcogen halides carbon supports
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Thermal Decomposition Kinetics of Ethane Halides and Derivatives(C_2H_(6-n)X_n(n = 1~3);X = F,Cl,Br):DFT Study and NBO Analysis 被引量:1
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作者 Abolfazl Shiroudi Ehsan Zahedi 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2011年第6期858-866,共9页
A theoretical study of the thermal decomposition kinetics of ethane halides(C2H6-nXn(n = 1~3);X = F,Cl,Br) has been carried out at the B3LYP/6-31++G** and B3PW91/631++G** levels of theory.Among these meth... A theoretical study of the thermal decomposition kinetics of ethane halides(C2H6-nXn(n = 1~3);X = F,Cl,Br) has been carried out at the B3LYP/6-31++G** and B3PW91/631++G** levels of theory.Among these methods and comparison of activation parameters with available experimental values,the B3PW91/6-31++G** method is in good agreement with the experimental data.The analysis of bond order and natural bond orbital(NBO) charges,bond indexes,and synchronicity parameters suggest the elimination of HX in reactions 1~9(HF:compounds 1~3,HCl:compounds 4~6,and HBr:compounds 7~9) occur through a concerted and slightly asynchronous four-membered cyclic transition state type of mechanism. 展开更多
关键词 elimination ab initio molecular modeling decomposition ethane halides NBO
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Photopromoted Carbonylation of Alkyl Halides Under Ambient Conditions 被引量:1
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作者 YanSUN JingMeiYIN +2 位作者 DaBinGAO GuangYunZHOU YingPingJIA 《Chinese Chemical Letters》 SCIE CAS CSCD 2003年第6期575-578,共4页
Photopromoted carbonylation of alkyl halides with carbon monoxide can be carried out under ambient conditions with non-precious transition metal complexes (such as cobalt complexes) catalysts. Our preliminary work sh... Photopromoted carbonylation of alkyl halides with carbon monoxide can be carried out under ambient conditions with non-precious transition metal complexes (such as cobalt complexes) catalysts. Our preliminary work showed that alkyl halides can be transformed into alkene and alkane directly under irradiation, but the esters can not be transformed. It is assumed that the carbonylation of alkyl halides may be proceeded in two ways. 展开更多
关键词 Photopromoted carbonylation alkyl halides carbon monoxide.
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The Supramolecular Arrangement of Methane Halides in Liquid Phase 被引量:1
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作者 Iosif Isaevich Greenwald Ivan Yurievich Kalagaev 《Journal of Chemistry and Chemical Engineering》 2011年第8期759-769,共11页
The IR spectroscopic data indicate the tautomeric transformations of typical aprotonic organic fluids such as methane halides with gross formulas CHX3 (X = Cl, Br), CH2X2 (X = CI, Br, I) and CCl4 at normal conditi... The IR spectroscopic data indicate the tautomeric transformations of typical aprotonic organic fluids such as methane halides with gross formulas CHX3 (X = Cl, Br), CH2X2 (X = CI, Br, I) and CCl4 at normal conditions. These transformations lead to the appearance in molecules of activated hydrogen atoms similar in the spectral behaviour to the bounded proton. The classical analysis of IR bands in 5000-600 cm^-1 region, for studied samples and their deuterated derivatives, proves the existence in the presented organic fluids of hydrogen and dihydrogen bonds. This bonding promotes the formation of supramolecular structure in methane halides. The mechanism of unusual binding in liquid phase in terms of common knowledge for the basic chemical properties of the examined compounds is discussed. 展开更多
关键词 SUPRAMOLECULE hydrogen bond dihydrogen bond methane halides IR spectroscopy
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Reaction of thiocarboxanilide derivatives of 2-phenylimino-3-phenyl-4-thiazolidinone and 1,3-diphenyl-2-thioxo-4-imidazolone with hydrazonoyl halides and active chloromethylene compounds 被引量:1
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作者 Hamdi M. Hassaneen Omar A. Miqdad +1 位作者 Nada M. Abunada Ahmad A. Fares 《Natural Science》 2011年第3期199-207,共9页
The potassium salts of thiocarboxanilide of 2- phenylimino-3-phenyl-4-thiazolidinone and 1,3- diphenyl-2-thioxo-4-imidazolone react with hydrazonoyl halides in N,N-dimethylformamide to afford the corresponding 1,3,4-t... The potassium salts of thiocarboxanilide of 2- phenylimino-3-phenyl-4-thiazolidinone and 1,3- diphenyl-2-thioxo-4-imidazolone react with hydrazonoyl halides in N,N-dimethylformamide to afford the corresponding 1,3,4-thiadiazoline derivatives. 2-Phenylimino-3-phenyl-4-thiazolidinone reacts with active chloromethylene compounds in N,N-dimethylformamide to give the corresponding thiazolylidenethiazolidin-4-one derivatives. The new compounds were characterized using IR, 1H NMR, 13C NMR and mass spectra. 展开更多
关键词 Hydrazonoyl halides 1 3 4-Thiadiazoline THIAZOLIDINONE
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A Quantum Chemical Study on Hexanuclear Cluster Halides of Rare Earth Elements and Their Interstitial Compounds
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作者 林梦海 张乾二 《Journal of Rare Earths》 SCIE EI CAS CSCD 1992年第2期93-97,共5页
The electronic structures of rare earth cluster halides R(R_6X_(12)) and their interstitial compounds R_7X_(12)Z were studied by the DV-X_(?) method (R=Sc,Y,Pr,Gd or Er;X=Cl,Br or I;Z=B,C,N,Fe,Co or Ru).The results sh... The electronic structures of rare earth cluster halides R(R_6X_(12)) and their interstitial compounds R_7X_(12)Z were studied by the DV-X_(?) method (R=Sc,Y,Pr,Gd or Er;X=Cl,Br or I;Z=B,C,N,Fe,Co or Ru).The results show that because f electrons in empty rare earth cluster are screened,their orbitals are more difficult to overlap each other,a deficiency of skeleton orbitals in cluster causing the system to be unstable.They are easily condensed into chain compound R_2X_3 or R_5X_8.If a light atom of main group is embedded into octahedral cluster,bonding orbitals formed from interstitial atom and rare earth cluster strengthen cluster skeleton bond in the system to reach structural stability.If embedded atom belongs to transition metal,bonding orbitals composed of that of interstitial atom and rare earth cluster take the place of original cluster skeleton orbitals to form heteronuclear metal cluster (or double-coordination compound). 展开更多
关键词 RE CLUSTER halides Interstitial compounds Quantum chemistry
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Synthesis of 2,5-disubstituted tetrahydrofurans from organozinc halides and lactones
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作者 Dan Feng Huang Hai Feng Wang +2 位作者 Chang Ming Xu Teng Niu Yu Lai Hu 《Chinese Chemical Letters》 SCIE CAS CSCD 2010年第5期511-514,共4页
2,5-Disubstituted tetrahydrofurans were obtained from lactones and organozinc halides in moderate to high yield in the presence of Lewis acids.
关键词 Organozinc halides LACTONES Lactols 2 5-Disubstituted tetrahydrofurans Lewis acid
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Palladium-catalyzed Cascade Cyclization-Coupling Reaction of Benzyl Halides with N, N-Diallylbenzoylamide
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作者 Yi Min HU Yu ZHANG +2 位作者 Jian Lin HAN Cheng Jian ZHU Yi PAN 《Chinese Chemical Letters》 SCIE CAS CSCD 2003年第8期771-772,共2页
A novel type of palladium-catalyzed cascade cyclization-coupling reaction has been found. Reaction of N, N-diallylbenzoylamide 1 with benzyl halides 2 afforded the corresponding dihydropyrroles 3 in moderate to excel... A novel type of palladium-catalyzed cascade cyclization-coupling reaction has been found. Reaction of N, N-diallylbenzoylamide 1 with benzyl halides 2 afforded the corresponding dihydropyrroles 3 in moderate to excellent yields. 展开更多
关键词 PALLADIUM Heck reaction benzyl halides CYCLIZATION cascade reaction.
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Dehalogenation of Aryl Halides Catalyzed by Montmorillonite Immobilized Bimetal Catalyst in Aqueous System
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作者 Erli Zheng Xuezhong Zheng 《Journal of Natural Gas Chemistry》 EI CAS CSCD 2006年第1期70-72,共3页
A novel bisupported bimetal catalyst PVP-PdCl2-FeSO4/Al-Mont-PEG600 was prepared by immobilization of PVP (poly (N-vinyl-2-pyrrolidone)) supported bimetallic catalyst using alumina pillared inartificial montmorill... A novel bisupported bimetal catalyst PVP-PdCl2-FeSO4/Al-Mont-PEG600 was prepared by immobilization of PVP (poly (N-vinyl-2-pyrrolidone)) supported bimetallic catalyst using alumina pillared inartificial montmorillonite as the carrier. This catalyst has good dehalogenation activity and selectivity to aryl halides o-chlorotoluene in aqueous system in the presence of phase transfer catalyst (PEG) and sodium formate as hydrogen source. The catalyst also shows good reusability. 展开更多
关键词 DEHALOGENATION aqueous system aryl halides pillared montmorillonite BIMETAL
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Visible‐light photoredox‐catalyzed carboxylation of benzyl halides with CO_(2):Mild and transition‐metal‐free
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作者 Ke Jing Ming‐Kai Wei +5 位作者 Si‐Shun Yan Li‐Li Liao Ya‐Nan Niu Shu‐Ping Luo Bo Yu Da‐Gang Yu 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2022年第7期1667-1673,共7页
The visible‐light photoredox‐catalyzed carboxylation of benzyl chlorides and bromides with CO_(2) has been reported.With inexpensive organic dyes as photocatalysts and amines as electron donors,this carboxylation pr... The visible‐light photoredox‐catalyzed carboxylation of benzyl chlorides and bromides with CO_(2) has been reported.With inexpensive organic dyes as photocatalysts and amines as electron donors,this carboxylation proceeds well in the absence of sensitive organometallic reagents,transition metal catalysts,or metallic reductants.A wide range of commercially available and inexpensive benzyl halides undergo such carboxylation to give valuable aryl acetic acids,including several pharmaceutical molecules and drug precursors,in moderate to high yields.Moreover,this reaction features mild reaction conditions(one atmospheric pressure of CO_(2) and room temperature),broad substrate scope,good functional group tolerance,easy scalability,and low catalyst loading,thus providing an efficient approach for the assembly of aryl acetic acids. 展开更多
关键词 Carbon dioxide Visible‐light photoredox catalysis CARBOXYLATION Aryl acetic acids Benzyl halides
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First-principles study of the local structure and crystal field of Yb^(2+) in sodium and potassium halides
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作者 闻军 段昌奎 +3 位作者 尹民 Yu.V.Orlovskii 夏上达 章永凡 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第3期349-354,共6页
The local coordination structures around the doping Yb2+ ions in sodium and potassium halides were calculated by using the first-principles supercell model. Both the cases with and without the charge compensation vac... The local coordination structures around the doping Yb2+ ions in sodium and potassium halides were calculated by using the first-principles supercell model. Both the cases with and without the charge compensation vacancy in the local environment of the doping Yb2+ were calculated to study the effect of the doping on the local coordination structures of Yb2+. Using the calculated local structures, we obtained the crystal-field parameters for the Yb2+ ions doped in sodium and potassium halides by a method based on the combination of the quantum-chemical calculations and the effective Hamiltonian method. The calculated crystal-field parameters were analyzed and compared with the fitted results. 展开更多
关键词 sodium and potassium halides local coordination structure DISTORTION crystal-field parameters
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