Structural analysis of and selective CO adsorption in mixed-ligand hydroxamate-based metal-organic frameworks

Two mixed-ligand metal-organic frameworks, [Zn 2 (BDHA) 0.5 (INA) 3 ] ( MOF-1 : H 2 BDHA = benzene-1,4-dihydroxamic acid; HINA = isonicotinic acid) and [Co 2 (BDHA) 0.5 (INA) 3 (DMF)] ( MOF-2 ), were solvothermally synthesized and fully characterized by single-crystal X-ray crystallography as well as N 2 , H 2 , and CO 2 gas-sorption measurements. The results constitute the first detailed analysis of the bonding environment around the hydroxamates in such MOFs, which are simultaneously decorated with Lewis-basic sites from the hydroxamate moieties and metal sites predisposed for coordinative unsaturation. MOF-2 shows a desirably selective adsorption of CO 2 relative to N 2 . Two mixed-ligand metal-organic frameworks using benzene-1,4-dihydroxamic acid and isonicotinic acid were synthesized and fully characterized by single-crystal X-ray crystallography as well as N 2 , H 2 , and CO 2 gas-sorption measurements.