A Foldable Metal–Organic Framework with cds Topology Assembled via Four-Connected Square-Planar Single Ni²⁺-Ion Nodes and Linear Bidentate Linkers

Abstract

A binary, three-dimensional (3D), foldable, Metal–Organic Framework (MOF) of formula {[trans-Ni(H2O)2(μ-4,4′-bpy)2](ClO4)2}n (1), with CdSO4 (65 8), cds, topology, based on four-connected (4-c) square-planar single Ni2+ ion nodes and two-connected (2-c) linear rigid 4,4′-bipyridine (4,4′-bpy) ligands, was synthesized and structurally characterized via single crystal X-ray crystallography. The 41° dihedral angle between two distinct coordination environments within the 3D network of 1 produced the self-dual topology of Ni2+ nodes. Two rectangular 1D channels ran parallel to the crystallographic a-axis and b-axis, respectively, creating a 44.2% volume porosity, probed by gas (N2, CO2, and H2) sorption studies. The PXRD, FT-IR, Raman, EDS, and SEM methods were employed for the study of 1. A thermogravimetric analysis (TGA) showed that coordinated water molecules were readily removed upon heating, whereas the 3D lattice remained intact up to 370 °C.

Keywords

• 3D MOF
• <b>cds</b>
• four-nodal
• single metal atom node
• bipyridine linker
• foldable network