A new bcu-MOF based upon a C2v-symmetrical[Cu_(4)Cl(COO)_(4)N_(8)]cluster,[Cu_(4)(Cl−)(L)_(4)·4H_(2)O]·(DMA^(+))·xDMF·yMeOH(SNNU-Bai66,SNNU-Bai=Shaanxi Normal University Bai's group),has been s...A new bcu-MOF based upon a C2v-symmetrical[Cu_(4)Cl(COO)_(4)N_(8)]cluster,[Cu_(4)(Cl−)(L)_(4)·4H_(2)O]·(DMA^(+))·xDMF·yMeOH(SNNU-Bai66,SNNU-Bai=Shaanxi Normal University Bai's group),has been sucessfully synthesized.By post-synthetic ion exchange experiments for the preparation of phases to be activated successfully,two new anionic derivatives,[Cu_(4)(Cl^(−))(L)_(4)·4H_(2)O]·[Li(H_(2)O)_(4)]^(+)·xDMK(Li^(+)-SNNU-Bai66,DMK=dimethyl ketone)and[Cu4(Cl−)(L)_(4)·_(4)H_(2)O]·(DMA^(+))·xDMK(DMA^(+)-SNNU-Bai66,DMA^(+)=Me_(2)NH_(2)),have been achieved and their selective CO_(2)or CH_(4)adsorptions over N_(2)gas have been systematically investigated in depth by both experimental and simulation studies.With the ionic pore surface and counterions cooperating with Lewis base N or O sites of the organic ligands in both Li^(+)-SNNU-Bai66 and DMA^(+)-SNNU-Bai66,the two MOFs exhibit highly selective CO_(2)and CH4 adsorption,especially for CH4 gas.Moreover,with the counterion being tuned from Li(H_(2)O)_(4)+to DMA^(+),selective CO_(2)adsorption properties are slightly optimized due to the higher polarizability of DMA^(+)and the preferred adsorption site changing from site I[the opposite side of Cl−toward Li(H_(2)O)_(4)^(+)]in Li^(+)-SNNU-Bai66 to site II(the position between the Hc atom of the L1 ligand and DMA^(+))in DMA^(+)-SNNU-Bai66,whereas those of CH_(4) of both MOFs are similar due to their having the same preferred adsorption site,namely,site I[the opposite side of Cl^(−)toward DMA^(+)or Li(H_(2)O)_(4)^(+)],in their frameworks.This work may further enrich the investigation of anionic MOFs in the field of selective gas adsorption with their inherent natures being more definitely displayed.展开更多
基金the National Natural Science Foundation of China(21771121)the Fundamental Research Funds for the Central Universities(No.GK201903040)for their support.
文摘A new bcu-MOF based upon a C2v-symmetrical[Cu_(4)Cl(COO)_(4)N_(8)]cluster,[Cu_(4)(Cl−)(L)_(4)·4H_(2)O]·(DMA^(+))·xDMF·yMeOH(SNNU-Bai66,SNNU-Bai=Shaanxi Normal University Bai's group),has been sucessfully synthesized.By post-synthetic ion exchange experiments for the preparation of phases to be activated successfully,two new anionic derivatives,[Cu_(4)(Cl^(−))(L)_(4)·4H_(2)O]·[Li(H_(2)O)_(4)]^(+)·xDMK(Li^(+)-SNNU-Bai66,DMK=dimethyl ketone)and[Cu4(Cl−)(L)_(4)·_(4)H_(2)O]·(DMA^(+))·xDMK(DMA^(+)-SNNU-Bai66,DMA^(+)=Me_(2)NH_(2)),have been achieved and their selective CO_(2)or CH_(4)adsorptions over N_(2)gas have been systematically investigated in depth by both experimental and simulation studies.With the ionic pore surface and counterions cooperating with Lewis base N or O sites of the organic ligands in both Li^(+)-SNNU-Bai66 and DMA^(+)-SNNU-Bai66,the two MOFs exhibit highly selective CO_(2)and CH4 adsorption,especially for CH4 gas.Moreover,with the counterion being tuned from Li(H_(2)O)_(4)+to DMA^(+),selective CO_(2)adsorption properties are slightly optimized due to the higher polarizability of DMA^(+)and the preferred adsorption site changing from site I[the opposite side of Cl−toward Li(H_(2)O)_(4)^(+)]in Li^(+)-SNNU-Bai66 to site II(the position between the Hc atom of the L1 ligand and DMA^(+))in DMA^(+)-SNNU-Bai66,whereas those of CH_(4) of both MOFs are similar due to their having the same preferred adsorption site,namely,site I[the opposite side of Cl^(−)toward DMA^(+)or Li(H_(2)O)_(4)^(+)],in their frameworks.This work may further enrich the investigation of anionic MOFs in the field of selective gas adsorption with their inherent natures being more definitely displayed.
