Two cyclohexane-type octadecanuclear metalla-macrocycle-based metal organic frameworks and adsorption properties†
Abstract
Two novel porous metal–organic frameworks (MOFs) with {M18(Hbtib)36} (M = Ni(II), Zn(II)) as the basic building unit, namely, [Ni(Hbtib)2]n (1) and [Zn(Hbtib)2·H2O]n (2) [H2btib = 4-((2-butyl-5-(2-carboxy-3-(thiophen-2-yl)prop-1-enyl)-1H-imidazol-1-yl)methyl)] were synthesized using solvothermal reactions. Gas adsorption (N2, H2, CO2 and CH4) studies show that the desolvated solid 1 is a highly effective absorbent for CO2 over CH4 at 273 and 298 K. The results suggest that 1 has potential application in gas separation or purification. In addition, the photoluminescence properties of 2 were also investigated.