Synthesis, structures, and CO2 sorption of a Cu(II) and Zn(II) two-fold interpenetrated pyridyl diimide metal–organic frameworks

Abstract

Herein we report synthesis, structures and CO2 sorption studies of two 2-fold interpenetrated three dimensional (3D) metal–organic frameworks (MOFs) namely; {[Cu(2,6-NDC)(L1)0.5]·3DMF}n (1) and {[Zn0.5(2,6-NDC)0.5(L2)0.5]·2DMF}n (2) where L1 is 5,5′-carbonylbis(2-(pyridin-3-ylmethyl)isoindoline-1,3-dione, L2 is 2,2′-bis(pyridin-4-ylmethyl)-[5,5′-biisoindoline]-1,1′–3,3′-tetraone, DMF is N,N’-dimethylformamide, and 2,6-NDC is 2,6-naphthalenedicarboxylic acid. The MOFs were synthesized solvothermally and characterized using single-crystal X-ray diffraction (SCXRD), thermogravimetric analysis (TGA), and powder X-ray diffraction (PXRD). SCXRD revealed that 1 and 2 are 3D and possess 33% and 27% of solvent-accessible volumes. Carbon dioxide sorption experiments were conducted at 195 K and 273 K on the desolvated phases of 1 (1-d) and 2 (2-d). 1-d adsorbs 11 cm3 g−1 (STP) at 273 K and 30 cm3 g−1 (STP) at 195 K, while 2-d adsorbs 35 cm3 g−1 (STP) at 273 K and 80 cm3 g−1 (STP) at 195 K.