A double stranded metal–organic assembly accommodating a pair of water trimers in the host cavity and catalysing Glaser coupling

Abstract

A supramolecular compound,catena-poly{[Cu2(1,3-μ2-(1a))2(μ2-ter)2(H2O)2]n·(6H2O)n} (1) has been synthesized using (1a) [(1a=N1,N3,N5-trimethyl-N1,N3,N5-tris((pyridin-4-yl)methyl)-1,3,5-benzene tricarboxamide] and terephthalate (ter) as the pillaring unit by self-assembly. The terephthalate units are connected by copper(II) ions forming a single strand, while a pair of such strands are then linked by (1a)viatwo pyridyl terminal arms bound to copper(II) nodes on either side forming a one-dimensional double stranded assembly propagating along thecaxis. The compound crystallizes in theFdd2 space group. The cavity created in the interior of this double strand assembly trap six water molecules and are stabilized by hydrogen bonding with the host. The arrangement of the pair of acyclic water trimers in isolated cavities of (1) is such that it resembles a closed-bracket-like formation. The Hirshfeld surface analysis of (1) reveals the presence of strong intermolecular hydrogen-bonding interactions between one-dimensional ladder-like units and with the water trimer in the host cavity. The copper(II)-containing coordination polymer also acts as an efficient catalyst for the Glaser–Hay homo-coupling reaction.