Isoreticular 3D zinc(II) frameworks constructed by unsymmetric 1,2,4-triazolate ligands: Syntheses, structures, and sorption properties

Three isoreticular metal-organic frameworks based on ternary zinc(II)/triazolate/X (X = OAc−, Cl−) metal azolate frameworks, namely [Zn(mtz)(OAc)]·H2O (1, Hmtz = 3-methyl-1,2,4-triazole), [Zn(etz)(OAc)]·0.5H2O (2, Hetz = 3-ethyl-1,2,4-triazole) and [Zn(metz)Cl]·0.25H2O (3, Hmetz = 3-methyl-5-ethyl-1,2,4-triazole), have been synthesized by changing the substituent groups on asymmetric 1,2,4-triazolates and auxiliary anions (OAc− or Cl−). These frameworks have a 3-connected 4.8.10-lvt-a topological network, which can be also simplified into a 4-connected lvt net by further denoting dinuclear [Zn2(triazole)2] subunits as a square-planar 4-connected node. 1 exhibits a porous structure with 1D (d = 3.0 Å) effective channels showing the selective adsorption behaviors of CO2 over N2, whereas 2 and 3 are nonporous structures.