Crystal Engineering of Three Net‐to‐Net Intersecting Metal–Organic Frameworks from Two Comparable Organic Linking Squares

Abstract

AbstractThe syntheses and structures of three mixed‐ligand metal–organic frameworks (MOFs), {[M2(btec)(bpym)(H2O)4]·4H2O}n [M = Cu (1), Ni (2)] and [Zn4(btec)2(bpym)(H2O)6]n (3) (btec = benzene‐1,2,4,5‐tetracarboxylate, bpym = 5,5′‐bipyrimidine) are described. MOFs 1 and 2 feature 3D grid‐type frameworks with a cds‐type topology, which are comprised of two mutually intersecting M(btec)‐based and M(bpym)‐based 44‐sql layers. MOF 3 consists of an anionic 3D (4,4)‐connected pts network that is intersected by cationic hydrogen‐bonded 44‐sql layers, [(H2O)3Zn(μ‐anti‐η2‐bpym)Zn(H2O)3]4+, thereby giving rise to a 3D network. The structural diversities between the two types of MOF architectures can be attributed to the coordination geometry preference of the metal ions (square planar for CuII and NiII and tetrahedral for ZnII). In addition, temperature‐controlled X‐ray powder diffraction studies reveal that MOF 1 possesses reversible desorption/sorption properties upon the removal/uptake of water molecules. The magnetic behavior of 1 was investigated in the 2–300 K range. The data indicate the presence of weak antiferromagnetic interactions between the two CuII metal centers that are bridged by a pyrimidine ring.