Cadmium(Cd)or excess copper(Cu)has a great impact in terms of toxicity on living organisms as it severely affects crop growth,yield and food security;thus,warranting appropriate measures for the remediation of Cd or C...Cadmium(Cd)or excess copper(Cu)has a great impact in terms of toxicity on living organisms as it severely affects crop growth,yield and food security;thus,warranting appropriate measures for the remediation of Cd or Cu polluted soils.Phytoextraction of heavy metal(HM)using tolerant plants along with organic chelators has gained global attention,and this study provided further insights into this issue.Pot experiments were performed to evaluate the effects of different types of chelators[ethylenediamine tetraacetic acid(EDTA),ethylenediamine disuccinic acid(EDDS)and citric acid(CA)]to improve the phytoextraction capacity of Ricinus communis L.for the metals Cd and Cu.Contaminated soil from a copper smelter was used in this study.A rhizon soil sampler was used to determine the metal concentrations in soil pore water.The results indicated that R.communis was an adequate candidate for chelator induced phytoextraction under the experimental conditions and that EDDS would be a good candidate chelator for the phytoextraction of Cu in soils.EDTA addition obviously improved the uptake of Cd and Cu in R.communis;however,it posed the greatest risk because the concentration of HMs in soil pore water was very high even after 40 days.Compared with EDTA and EDDS,CA had few effects on Cd or Cu uptake in R.communis.Linear relationships between the metal uptake in R.communis shoots and the maximum HM concentrations in soil pore water under HM,2.5,5,and 10 mmol·kg^(-1) treatments were typically observed.From the results of this study,it could be concluded that EDDS treatments played a promising role in increasing the uptake of Cd or Cu and reducing its phytotoxicity.EDDS application could be an effective approach for the phytoextraction of Cd or Cu from polluted soils by growing Ricinus communis L.展开更多
To achieve efficient catalytic hydrogenation of CO_(2)to formate,we employed a transmetallation strategy to develop three novel iridium(Ⅰ)complexes,which feature N‑heterocyclic carbene‑nitrogen‑phosphine ligands(CNP)...To achieve efficient catalytic hydrogenation of CO_(2)to formate,we employed a transmetallation strategy to develop three novel iridium(Ⅰ)complexes,which feature N‑heterocyclic carbene‑nitrogen‑phosphine ligands(CNP)and a 1,5‑cyclooctadiene(cod)molecule:[Ir(cod)(κ^(3)‑CN^(im)P)]Cl(1⁃Cl),[Ir(cod)(κ^(3)‑CN^(im)P)]PF6(1⁃PF_(6)),and[Ir(cod)(κ^(3)‑CNHP)]Cl(2).The^(1)H NMR spectra,^(31)P NMR spectra,and high‑resolution mass spectra verify the successful synthesis of these three Ir(Ⅰ)‑CNP complexes.Furthermore,single‑crystal X‑ray diffraction analysis confirms the coordination geometry of 1⁃PF_(6).The strong Ir—C(NHC)bond suggests that the carbene carbon plays an enhanced anchoring role to iridium due to its strongσ‑donating ability,which helps stabilize the active metal species during CO_(2)hydrogenation.As a result,the Ir(Ⅰ)‑CNP complex exhibits remarkable activity and long catalytic lifetime for the hydrogenation of CO_(2)to formate,reaching a turnover number(TON)of 1.16×10^(6)after 150 h at a high temperature of 170℃,which was a relatively high value among all the Ir complexes.CCDC:2384071,1⁃PF_(6).展开更多
基金Supported by the Joint Funds of the National Natural Science Foundation of China(U2340219)。
文摘Cadmium(Cd)or excess copper(Cu)has a great impact in terms of toxicity on living organisms as it severely affects crop growth,yield and food security;thus,warranting appropriate measures for the remediation of Cd or Cu polluted soils.Phytoextraction of heavy metal(HM)using tolerant plants along with organic chelators has gained global attention,and this study provided further insights into this issue.Pot experiments were performed to evaluate the effects of different types of chelators[ethylenediamine tetraacetic acid(EDTA),ethylenediamine disuccinic acid(EDDS)and citric acid(CA)]to improve the phytoextraction capacity of Ricinus communis L.for the metals Cd and Cu.Contaminated soil from a copper smelter was used in this study.A rhizon soil sampler was used to determine the metal concentrations in soil pore water.The results indicated that R.communis was an adequate candidate for chelator induced phytoextraction under the experimental conditions and that EDDS would be a good candidate chelator for the phytoextraction of Cu in soils.EDTA addition obviously improved the uptake of Cd and Cu in R.communis;however,it posed the greatest risk because the concentration of HMs in soil pore water was very high even after 40 days.Compared with EDTA and EDDS,CA had few effects on Cd or Cu uptake in R.communis.Linear relationships between the metal uptake in R.communis shoots and the maximum HM concentrations in soil pore water under HM,2.5,5,and 10 mmol·kg^(-1) treatments were typically observed.From the results of this study,it could be concluded that EDDS treatments played a promising role in increasing the uptake of Cd or Cu and reducing its phytotoxicity.EDDS application could be an effective approach for the phytoextraction of Cd or Cu from polluted soils by growing Ricinus communis L.
文摘To achieve efficient catalytic hydrogenation of CO_(2)to formate,we employed a transmetallation strategy to develop three novel iridium(Ⅰ)complexes,which feature N‑heterocyclic carbene‑nitrogen‑phosphine ligands(CNP)and a 1,5‑cyclooctadiene(cod)molecule:[Ir(cod)(κ^(3)‑CN^(im)P)]Cl(1⁃Cl),[Ir(cod)(κ^(3)‑CN^(im)P)]PF6(1⁃PF_(6)),and[Ir(cod)(κ^(3)‑CNHP)]Cl(2).The^(1)H NMR spectra,^(31)P NMR spectra,and high‑resolution mass spectra verify the successful synthesis of these three Ir(Ⅰ)‑CNP complexes.Furthermore,single‑crystal X‑ray diffraction analysis confirms the coordination geometry of 1⁃PF_(6).The strong Ir—C(NHC)bond suggests that the carbene carbon plays an enhanced anchoring role to iridium due to its strongσ‑donating ability,which helps stabilize the active metal species during CO_(2)hydrogenation.As a result,the Ir(Ⅰ)‑CNP complex exhibits remarkable activity and long catalytic lifetime for the hydrogenation of CO_(2)to formate,reaching a turnover number(TON)of 1.16×10^(6)after 150 h at a high temperature of 170℃,which was a relatively high value among all the Ir complexes.CCDC:2384071,1⁃PF_(6).
