Self-assembly of hydrogen-bonded networks of [Cu(HL)Cl](PF₆)

Abstract

A new mononuclear copper(II) complex [Cu(HL)Cl](PF₆) (1) having an N₄O-donor ligand (HL = N,N-bis(2-pyridylmethyl)-1,3-diaminopropan-2-ol) has been synthesized and structurally characterized by X-ray crystallography. 1 shows a 1D chain in the packing structure through intermolecular O–H---Cl strong hydrogen bonding interaction (O–H---Cl, 1.99(4) Å and the angle (O–H---Cl) 163(4)º). The packing structure of 1 also shows л–л stacking [close contact 3.325a Å (a = 2-X,-Y,-Z)] of the large aromatic pyridine rings between adjacent chains. The 1D structure stabilized by this type of л–л stacking interaction between adjacent chains leads to a 2D supramolecular network. A submicrometer rod structure of [Cu(HL)Cl](PF₆) with a diameter of 580 nm and a length of several microns has been prepared by drop casting method from the methanolic solution of 1. The morphology of submicrometer rod of 1 has been studied by SEM. The driving force for the growth of [Cu(HL)Cl](PF₆) rods is probably the strong intermolecular O–H---Cl hydrogen bonding interaction along the 1D chain and л–л stacking interaction between the adjacent chains.