The assembly of high-nuclearity lanthanide nanoclusters with favourable magnetocaloric effects suffers from a significant challenge.Herein,two outstanding examples of cage-shaped nanoclusters,namely,[Ln_(28)(IN)_(25)(...The assembly of high-nuclearity lanthanide nanoclusters with favourable magnetocaloric effects suffers from a significant challenge.Herein,two outstanding examples of cage-shaped nanoclusters,namely,[Ln_(28)(IN)_(25)(C_(2)O_(4))_(6)(HCOO)(μ_(3)-OH)_(36)(μ_(2)-OH)_(2)(H_(2)O)_(36)]·8Br·xH_(2)O(Ln=Gd and Eu;x=21,abbreviated as Gd_(28);x=17,abbreviated as Eu_(28),HIN=isonicotinic acid;H_(2)C_(2)O_(4)=oxalic acid)have been triumphantly designed and constructed under hydrothermal conditions.The crystallographic study revealed that the aesthetically pleasing triangle-shaped Gd_(12) subunit and Gd_(16) subunit built separately from four Gd_(3) units and four Gd_(4) units,respectively,are shaped into an unprecedented cage-shaped configuration.Prominently,six small and simple C_(2)O_(4)^(2-)anions generated via the in situ reaction of HIN are faultlessly anchored in the cage-shaped framework.Furthermore,the existence of abundant Gd^(Ⅲ) ions impart Gd_(28) with a captivating magnetic entropy change(−ΔS_(m)^(max)=37.5 J kg^(−1)K^(−1))at 2.0 K for ΔH=7.0 T.展开更多
An open-framework silicoaluminophosphate(SAPO)material with a composition of Cs_(2)(Al_(0.875)Si_(0.125))4(P_(0.875)Si_(0.125)O_(4))_(4)(HPO_(4))was synthesized in an organic template-free cesium-containing system und...An open-framework silicoaluminophosphate(SAPO)material with a composition of Cs_(2)(Al_(0.875)Si_(0.125))4(P_(0.875)Si_(0.125)O_(4))_(4)(HPO_(4))was synthesized in an organic template-free cesium-containing system under hydrothermal conditions.The material was resolved to be isostructural with an open-framework aluminophosphate(AlPO)material AlPO-CJ19,which was previously synthesized using pyridine as the solvent and 2-aminopyridine as the organic template via a solvothermal route.The substitution of organic templates by alkaline cations not only makes the current synthesis protocol more favorable from an environmental point of view but also leads to a significantly improved thermal stability of this structure.The framework remained completely stable at a temperature of 510℃.A high-temperature polymorph was discerned at a temperature higher than 540℃,the structure of which is revealed to crystallize in the P1c1 space group.UV-vis results reveal that cobalt and copper cations could be readily incorporated through simple ion-exchange treatment.The conductivity of the material is 1.70×10^(-4) S cm^(-1)(293 K,30%relative humidity)as revealed by the alternating current(A.C.)impedance spectroscopy analysis.This is the first report of the synthesis of a silicon-containing phase with an AlPO-CJ19 structure.展开更多
In this work,we reported an energy-saving and cost-efficient process for the(re)generation of NaBH_(4)by ball milling hydrated borax(Na_(2)B_(4)O_(7)·10H_(2)O)with a Mg–Al alloy under ambient conditions.The intr...In this work,we reported an energy-saving and cost-efficient process for the(re)generation of NaBH_(4)by ball milling hydrated borax(Na_(2)B_(4)O_(7)·10H_(2)O)with a Mg–Al alloy under ambient conditions.The introduction of abundant and readily available Al can increase air stability of the reducing agent.A high yield up to 85.2%could be achieved by using Mg_(17)Al_(12)because of its hardness and brittleness.展开更多
In this study,we present a convenient method to obtain two types of novel tetra-substituted Fe/Se salts through a dehalogenation reaction,aiming to advance research on mimicking the FeⅡFeⅡ oxidation state of[FeFe]-H...In this study,we present a convenient method to obtain two types of novel tetra-substituted Fe/Se salts through a dehalogenation reaction,aiming to advance research on mimicking the FeⅡFeⅡ oxidation state of[FeFe]-H_(2) ases.Initially,by treating[Fe_(2)(μ-SeBn)_(2)(CO)_(4)(dppv)](Bn=CH_(2)C_(6)H_(5),dppv=cis-1,2-bis(diphenylphosphino)ethylene)with one equivalent of dppv under UV and reflux conditions,the neutral FeIFeI and FeⅡFeⅡ precursors[Fe_(2)(μ-SeBn)_(2)(CO)_(2)(dppv)_(2)](1)and[Fe_(2)(μ-SeBn)_(2)(μ-Se)(CO)_(2)(dppv)_(2)](2)were successfully isolated in good yields.Subsequently,1 underwent dehalogenation reactions with halocarbons(such as CCl_(4) and CBr4)or I_(2),leading to the formation of tetra-substituted salts[Fe_(2)(μ-SeBn)_(2)(μ-X)(CO)_(2)(dppv)_(2)]+(X=Cl,Br,and I)([3]Cl,[4]Br and[5]I_(3)).GC-MS analysis of the reaction with carbon tetrachloride detected the formation of the homo-coupled product CCl_(3)-CCl_(3)(m/z=235),indicating the presence of a CCl_(3)·species.Notably,2 also exhibited intriguing reactivity with R-X and I_(2).Unlike 1,the reaction of 2 with RX or I_(2) involved cleavage of the C-Se bond,leading to the isolation of[Fe_(2)(μ-SeBn)(μ-Se_(2))(CO)_(2)(dppv)_(2)]+X-(X=Cl,Br,I_(3))([6]Cl,[6]Br and[6]I_(3))in good yields.The reaction involved debenzylation of 2 and was confirmed by GC-MS detection of C6H5CH_(2)CCl_(3)(m/z=208)in the reaction with CCl_(4),suggesting a radical pathway.展开更多
基金supported by the Natural Science Foundation of China(Grant 92161109).
文摘The assembly of high-nuclearity lanthanide nanoclusters with favourable magnetocaloric effects suffers from a significant challenge.Herein,two outstanding examples of cage-shaped nanoclusters,namely,[Ln_(28)(IN)_(25)(C_(2)O_(4))_(6)(HCOO)(μ_(3)-OH)_(36)(μ_(2)-OH)_(2)(H_(2)O)_(36)]·8Br·xH_(2)O(Ln=Gd and Eu;x=21,abbreviated as Gd_(28);x=17,abbreviated as Eu_(28),HIN=isonicotinic acid;H_(2)C_(2)O_(4)=oxalic acid)have been triumphantly designed and constructed under hydrothermal conditions.The crystallographic study revealed that the aesthetically pleasing triangle-shaped Gd_(12) subunit and Gd_(16) subunit built separately from four Gd_(3) units and four Gd_(4) units,respectively,are shaped into an unprecedented cage-shaped configuration.Prominently,six small and simple C_(2)O_(4)^(2-)anions generated via the in situ reaction of HIN are faultlessly anchored in the cage-shaped framework.Furthermore,the existence of abundant Gd^(Ⅲ) ions impart Gd_(28) with a captivating magnetic entropy change(−ΔS_(m)^(max)=37.5 J kg^(−1)K^(−1))at 2.0 K for ΔH=7.0 T.
基金support from the Sino-French joint laboratory“Zeolites”.
文摘An open-framework silicoaluminophosphate(SAPO)material with a composition of Cs_(2)(Al_(0.875)Si_(0.125))4(P_(0.875)Si_(0.125)O_(4))_(4)(HPO_(4))was synthesized in an organic template-free cesium-containing system under hydrothermal conditions.The material was resolved to be isostructural with an open-framework aluminophosphate(AlPO)material AlPO-CJ19,which was previously synthesized using pyridine as the solvent and 2-aminopyridine as the organic template via a solvothermal route.The substitution of organic templates by alkaline cations not only makes the current synthesis protocol more favorable from an environmental point of view but also leads to a significantly improved thermal stability of this structure.The framework remained completely stable at a temperature of 510℃.A high-temperature polymorph was discerned at a temperature higher than 540℃,the structure of which is revealed to crystallize in the P1c1 space group.UV-vis results reveal that cobalt and copper cations could be readily incorporated through simple ion-exchange treatment.The conductivity of the material is 1.70×10^(-4) S cm^(-1)(293 K,30%relative humidity)as revealed by the alternating current(A.C.)impedance spectroscopy analysis.This is the first report of the synthesis of a silicon-containing phase with an AlPO-CJ19 structure.
基金supported by the National Natural Science Foundation of China Projects(No.51771075 and 52001125)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(No.NSFC51621001)+1 种基金the Macao Science and Technology Development Fund(FDCT)(project number 0019/2019/AGJ)the Guangdong-Hong Kong-Macao Joint Laboratory(grant no.2019B121205001).
文摘In this work,we reported an energy-saving and cost-efficient process for the(re)generation of NaBH_(4)by ball milling hydrated borax(Na_(2)B_(4)O_(7)·10H_(2)O)with a Mg–Al alloy under ambient conditions.The introduction of abundant and readily available Al can increase air stability of the reducing agent.A high yield up to 85.2%could be achieved by using Mg_(17)Al_(12)because of its hardness and brittleness.
基金the Natural Science Foundation of Shandong Province(No.ZR2020MB019)Introduction and Cultivation Project for Young Innovative Talents in Shandong Provincial Colleges and Universities for financial support.
文摘In this study,we present a convenient method to obtain two types of novel tetra-substituted Fe/Se salts through a dehalogenation reaction,aiming to advance research on mimicking the FeⅡFeⅡ oxidation state of[FeFe]-H_(2) ases.Initially,by treating[Fe_(2)(μ-SeBn)_(2)(CO)_(4)(dppv)](Bn=CH_(2)C_(6)H_(5),dppv=cis-1,2-bis(diphenylphosphino)ethylene)with one equivalent of dppv under UV and reflux conditions,the neutral FeIFeI and FeⅡFeⅡ precursors[Fe_(2)(μ-SeBn)_(2)(CO)_(2)(dppv)_(2)](1)and[Fe_(2)(μ-SeBn)_(2)(μ-Se)(CO)_(2)(dppv)_(2)](2)were successfully isolated in good yields.Subsequently,1 underwent dehalogenation reactions with halocarbons(such as CCl_(4) and CBr4)or I_(2),leading to the formation of tetra-substituted salts[Fe_(2)(μ-SeBn)_(2)(μ-X)(CO)_(2)(dppv)_(2)]+(X=Cl,Br,and I)([3]Cl,[4]Br and[5]I_(3)).GC-MS analysis of the reaction with carbon tetrachloride detected the formation of the homo-coupled product CCl_(3)-CCl_(3)(m/z=235),indicating the presence of a CCl_(3)·species.Notably,2 also exhibited intriguing reactivity with R-X and I_(2).Unlike 1,the reaction of 2 with RX or I_(2) involved cleavage of the C-Se bond,leading to the isolation of[Fe_(2)(μ-SeBn)(μ-Se_(2))(CO)_(2)(dppv)_(2)]+X-(X=Cl,Br,I_(3))([6]Cl,[6]Br and[6]I_(3))in good yields.The reaction involved debenzylation of 2 and was confirmed by GC-MS detection of C6H5CH_(2)CCl_(3)(m/z=208)in the reaction with CCl_(4),suggesting a radical pathway.
