The electrochemistry of (TPP)Co in the presence of pyridine was investigated in dichloroethane solution by cyclic voltammetry. With the addition of pyridine to the solution, the reduction peaks of the axial complex co...The electrochemistry of (TPP)Co in the presence of pyridine was investigated in dichloroethane solution by cyclic voltammetry. With the addition of pyridine to the solution, the reduction peaks of the axial complex compounds, (TPP)Co(III)(Py) and (TPP)Co(III)(Py)(2) were observed. It was found that the reduction peak of Co(II)/Co(I) shifted to about -1.20V (SCE) with the increase of added pyridine. The new reduction peak may be attributed to the direct reduction of the axially complex (TPP)Co(II)(Py).展开更多
The chain reaction of 1,2-dichloroethane was initiated by photosensitization of SF_6 under the selective excitation using a cw CO_2 laser.Vinyl chloride with high purity was produced in the reaction process.The initia...The chain reaction of 1,2-dichloroethane was initiated by photosensitization of SF_6 under the selective excitation using a cw CO_2 laser.Vinyl chloride with high purity was produced in the reaction process.The initiation of the photosensitized chain reaction depends on the irradiated laser frequency.The mechanism of intermolecular resonant transfer of vibrational energy has been discussed.展开更多
A novel route for tandem C-C/C-N formation,annulation and aromatization of hydrazones with 1,2-dichloroethane to synthesize 1 H-pyrazoles has been developed.Furthermore,the 1,2-dichloroethane serves as alkylation reag...A novel route for tandem C-C/C-N formation,annulation and aromatization of hydrazones with 1,2-dichloroethane to synthesize 1 H-pyrazoles has been developed.Furthermore,the 1,2-dichloroethane serves as alkylation reagent in good to excellent yields.This methodology features mild reaction conditions and good functional group tolerance,providing a direct approach for the preparation of 1 Hpvrazoles.展开更多
HZSM-5, Al_2O_3, TiO_2 and SiO_2 supported CeO_2-ZrO_2-CrO_x catalysts were prepared by deposition-precipitation method and tested for deep catalytic oxidation of 1,2-dichloroethane（DCE）, as one of the common chlori...HZSM-5, Al_2O_3, TiO_2 and SiO_2 supported CeO_2-ZrO_2-CrO_x catalysts were prepared by deposition-precipitation method and tested for deep catalytic oxidation of 1,2-dichloroethane（DCE）, as one of the common chlorinated organic pollutants. All the catalysts were characterized by means of N_2 adsorption-desorption, X-ray photoelectron spectroscopy（XPS）, ammonia-temperatureprogrammed desorption（NH_3-TPD） and hydrogen temperature-programmed reduction（H2-TPR）. The characterization results revealed that there was strongly synergistic effect between the oxidizability of CZCr species and the acidity of supports, which obviously promoted the catalytic activity for DCE degradation. 20% CZCr/HZSM-5 showed the highest activity and good durability during the long-term continuous test. The catalytic activity decreased in the order： 20%CZCr/HZSM-5〉CZCr〉20%CZCr/TiO_2〉20%CZCr/Al_2O_3〉20%CZCr/SiO_2.展开更多
Facilitated ion transfer reactions of 20 amino acids with dibenzo-18-crown-6 (DB18C6) at the water/1,2-dichloroethane (W/DCE) interfaces supported at the tips of micro- and nano-pipets were investigated systematically...Facilitated ion transfer reactions of 20 amino acids with dibenzo-18-crown-6 (DB18C6) at the water/1,2-dichloroethane (W/DCE) interfaces supported at the tips of micro- and nano-pipets were investigated systematically using cyclic voltammetry. It was found that there were only 10 amino acids, that is, Leu, Val, Ile, Phe, Trp, Met, Ala, Gly, Cys, Gln (in brief), whose protonated forms as cations can give well-defined facilitated ion transfer voltammograms within the potential window, and the reaction pathway was proven to be consistent with the transfer by interfacial complexation/dissociation (TIC/TID) mechanisms. The association constants of DB 18C6 with different amino acids in the DCE (β0), and the kinetic parameters of reaction were evaluated based on the steady-state voltammetry of micro- or nano-pipets, respectively. The experimental results demonstrated that the selectivity of complexation of protonated amino acid by DB18C6 compared with that of alkali metal cations was low, which can be attributed to the vicinal effect arising from steric hindrance introduced by their side group and the steric bulk effect by lipophilic stabilization. Moreover, the association constants and the standard rate constants for different amino acids showed good correlations with their hydrophobicity (π), except Gly and Met, which inferred that the selectivity of such heterogeneous complex reaction for different amino acids with DB18C6, was not only affected by discrimination in binding these ions to the crown ether macro-cycle, but also significantly modified by the ion transfer Gibbs energy which was closely related to the structure of the transferred ions, protonated amino acids.展开更多
The faradaic ion transfer of protonated 1,10-phenanthrolino [H(Phen)^+] across the interface between unbuffered aqueous and 1,2-dichloroethane(DCE)solutions was inves- tigated by means of current scan polarography at ...The faradaic ion transfer of protonated 1,10-phenanthrolino [H(Phen)^+] across the interface between unbuffered aqueous and 1,2-dichloroethane(DCE)solutions was inves- tigated by means of current scan polarography at ascending aqueous electrolyte electrode, as well as chronopotentiometry.It follows from the splitting of the waves observed at the pH of aqueous phase(sodium sulfate solution)between 2.5—3.8 that neutral reagent(Phen) distributes into the aqueous phase,where it is protonated.The positive wave is associated with the mass transfer controlled by the H^+ influx,whereas the negative one is by the Phen influx.The reverse chronopotentiometry indicated that all the protonated transfer processes were reversible.A good agreement between experimental results and theoretical treatment was achieved.The aqueous acid dissociation constant of protonated Phen,K_a,can be evalu- ated from the dependence of the wave heights on the pH in the base of the equilibrium.展开更多
Background and Aims:Intoxications by aliphatic halogenated hydrocarbons(AHH),used as effective solvents,are rare and may cause life-threatening liver injury.Patients with acute intoxications by AHH received an innovat...Background and Aims:Intoxications by aliphatic halogenated hydrocarbons(AHH),used as effective solvents,are rare and may cause life-threatening liver injury.Patients with acute intoxications by AHH received an innovative treatment.Methods:Analyzed were data of 60 patients intoxicated by AHH,such as dichloromethane(n=3),chloroform(n=2),carbon tetrachloride(n=12),1,2-dichloroethane(n=18),1,1,2-trichloroethane(n=2),trichloroethylene(n=2),tetrachloroethylene(n=13)or mixed AHH chemicals(n=8),who received a new treatment consisting of CO2-induced hyperventilation to accelerate toxin removal via the lungs.Results:Added to the inspiration air at a flow rate of 2-3 Liter min-1,CO2 increased the respiratory volume up to 25-30 Liter min-1,ensuring forced AHH exhalation.This CO2-induced hyperventilation therapy was commonly well tolerated by the 60 patients and lasted for 106.0±10.5 hours.In most cases,initially increased liver test results of aminotransferases normalized quickly under the therapy,and liver histology obtained at completion of the therapy revealed,in the majority of patients,normal findings or fatty changes,and rarely severe single cell necrosis but no confluent liver cell necrosis.Despite therapy,clinical outcome was unfavorable for 4/60 patients(6.7%)of the study cohort,due to single or combined risk factors.These included late initiation of the CO2-induced hyperventilation therapy,intentional intoxication,uptake of high amounts of AHH,concomitant ingestion of overdosed drugs,consumption of high amounts of alcohol,and history of alcohol abuse.Conclusions:For intoxications by AHH,effective therapy approaches including forced hyperventilation to increase toxin removal via the lungs are available and require prompt initiation.展开更多
文摘The electrochemistry of (TPP)Co in the presence of pyridine was investigated in dichloroethane solution by cyclic voltammetry. With the addition of pyridine to the solution, the reduction peaks of the axial complex compounds, (TPP)Co(III)(Py) and (TPP)Co(III)(Py)(2) were observed. It was found that the reduction peak of Co(II)/Co(I) shifted to about -1.20V (SCE) with the increase of added pyridine. The new reduction peak may be attributed to the direct reduction of the axially complex (TPP)Co(II)(Py).
文摘The chain reaction of 1,2-dichloroethane was initiated by photosensitization of SF_6 under the selective excitation using a cw CO_2 laser.Vinyl chloride with high purity was produced in the reaction process.The initiation of the photosensitized chain reaction depends on the irradiated laser frequency.The mechanism of intermolecular resonant transfer of vibrational energy has been discussed.
基金financial support for this research from Shandong Provincial Natural Science Foundation(No.ZR2017LB006)Academic promotion programme of Shandong First Medical University(No.2019LJ003)。
文摘A novel route for tandem C-C/C-N formation,annulation and aromatization of hydrazones with 1,2-dichloroethane to synthesize 1 H-pyrazoles has been developed.Furthermore,the 1,2-dichloroethane serves as alkylation reagent in good to excellent yields.This methodology features mild reaction conditions and good functional group tolerance,providing a direct approach for the preparation of 1 Hpvrazoles.
基金Project supports from National Nature Science Foundation of China(21177110)
文摘HZSM-5, Al_2O_3, TiO_2 and SiO_2 supported CeO_2-ZrO_2-CrO_x catalysts were prepared by deposition-precipitation method and tested for deep catalytic oxidation of 1,2-dichloroethane（DCE）, as one of the common chlorinated organic pollutants. All the catalysts were characterized by means of N_2 adsorption-desorption, X-ray photoelectron spectroscopy（XPS）, ammonia-temperatureprogrammed desorption（NH_3-TPD） and hydrogen temperature-programmed reduction（H2-TPR）. The characterization results revealed that there was strongly synergistic effect between the oxidizability of CZCr species and the acidity of supports, which obviously promoted the catalytic activity for DCE degradation. 20% CZCr/HZSM-5 showed the highest activity and good durability during the long-term continuous test. The catalytic activity decreased in the order： 20%CZCr/HZSM-5〉CZCr〉20%CZCr/TiO_2〉20%CZCr/Al_2O_3〉20%CZCr/SiO_2.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.20235010,20173058 and 2985111)the Special 985 Project of Peking University.
文摘Facilitated ion transfer reactions of 20 amino acids with dibenzo-18-crown-6 (DB18C6) at the water/1,2-dichloroethane (W/DCE) interfaces supported at the tips of micro- and nano-pipets were investigated systematically using cyclic voltammetry. It was found that there were only 10 amino acids, that is, Leu, Val, Ile, Phe, Trp, Met, Ala, Gly, Cys, Gln (in brief), whose protonated forms as cations can give well-defined facilitated ion transfer voltammograms within the potential window, and the reaction pathway was proven to be consistent with the transfer by interfacial complexation/dissociation (TIC/TID) mechanisms. The association constants of DB 18C6 with different amino acids in the DCE (β0), and the kinetic parameters of reaction were evaluated based on the steady-state voltammetry of micro- or nano-pipets, respectively. The experimental results demonstrated that the selectivity of complexation of protonated amino acid by DB18C6 compared with that of alkali metal cations was low, which can be attributed to the vicinal effect arising from steric hindrance introduced by their side group and the steric bulk effect by lipophilic stabilization. Moreover, the association constants and the standard rate constants for different amino acids showed good correlations with their hydrophobicity (π), except Gly and Met, which inferred that the selectivity of such heterogeneous complex reaction for different amino acids with DB18C6, was not only affected by discrimination in binding these ions to the crown ether macro-cycle, but also significantly modified by the ion transfer Gibbs energy which was closely related to the structure of the transferred ions, protonated amino acids.
基金Project supported by the National Natural Science Foundation of China.
文摘The faradaic ion transfer of protonated 1,10-phenanthrolino [H(Phen)^+] across the interface between unbuffered aqueous and 1,2-dichloroethane(DCE)solutions was inves- tigated by means of current scan polarography at ascending aqueous electrolyte electrode, as well as chronopotentiometry.It follows from the splitting of the waves observed at the pH of aqueous phase(sodium sulfate solution)between 2.5—3.8 that neutral reagent(Phen) distributes into the aqueous phase,where it is protonated.The positive wave is associated with the mass transfer controlled by the H^+ influx,whereas the negative one is by the Phen influx.The reverse chronopotentiometry indicated that all the protonated transfer processes were reversible.A good agreement between experimental results and theoretical treatment was achieved.The aqueous acid dissociation constant of protonated Phen,K_a,can be evalu- ated from the dependence of the wave heights on the pH in the base of the equilibrium.
文摘Background and Aims:Intoxications by aliphatic halogenated hydrocarbons(AHH),used as effective solvents,are rare and may cause life-threatening liver injury.Patients with acute intoxications by AHH received an innovative treatment.Methods:Analyzed were data of 60 patients intoxicated by AHH,such as dichloromethane(n=3),chloroform(n=2),carbon tetrachloride(n=12),1,2-dichloroethane(n=18),1,1,2-trichloroethane(n=2),trichloroethylene(n=2),tetrachloroethylene(n=13)or mixed AHH chemicals(n=8),who received a new treatment consisting of CO2-induced hyperventilation to accelerate toxin removal via the lungs.Results:Added to the inspiration air at a flow rate of 2-3 Liter min-1,CO2 increased the respiratory volume up to 25-30 Liter min-1,ensuring forced AHH exhalation.This CO2-induced hyperventilation therapy was commonly well tolerated by the 60 patients and lasted for 106.0±10.5 hours.In most cases,initially increased liver test results of aminotransferases normalized quickly under the therapy,and liver histology obtained at completion of the therapy revealed,in the majority of patients,normal findings or fatty changes,and rarely severe single cell necrosis but no confluent liver cell necrosis.Despite therapy,clinical outcome was unfavorable for 4/60 patients(6.7%)of the study cohort,due to single or combined risk factors.These included late initiation of the CO2-induced hyperventilation therapy,intentional intoxication,uptake of high amounts of AHH,concomitant ingestion of overdosed drugs,consumption of high amounts of alcohol,and history of alcohol abuse.Conclusions:For intoxications by AHH,effective therapy approaches including forced hyperventilation to increase toxin removal via the lungs are available and require prompt initiation.
