Cd(II) and Cu(II) Coordination Polymers Constructed from the Expanded 1,4-Bis(4 Ligand: Conventional and Ultrasound-Assisted Synthesis, Crystal Structure, Luminescence and Magnetic Properties

Abstract

A 3D open inorganic/organic framework, {[Cd(μ-L)(μ<inf>3</inf>-SO<inf>4</inf>)(H<inf>2</inf>O)]·H<inf>2</inf>O}<inf>n</inf> (1) [L = 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene] was synthesized by the reaction of CdSO<inf>4</inf>·8H<inf>2</inf>O with L. The treatment of Cu(NO<inf>3</inf>)<inf>2</inf>·3H<inf>2</inf>O with the same N,N′-donor ligand in two different solvent mixtures, methanol/dichloromethane (2) and methanol/chloroform (3), afforded two new ladder-like coordination polymers of formula {[Cu(μ-L)(μ-NO<inf>3</inf>)(NO<inf>3</inf>)]·solv}<inf>n</inf> [solv = CH<inf>2</inf>Cl<inf>2</inf> (2) and CHCl<inf>3</inf> (3)]. The non-interpenetrated ladder motifs 2 and 3 enclathrate the uncoordinated solvent molecules. Crystalline coordination polymers 1 and 3 were also successfully prepared by a sonochemical method under different reaction conditions. Our results indicate that the size of the particles is dependent on the irradiation time. 1 and 3 exhibit intense luminescent emissions in the solid state at room temperature. Cryomagnetic measurements of 3 show the occurrence of a ferromagnetic interaction between the copper(ii) ions through the double oxo-nitrate bridge together with a very weak inter-ladder antiferromagnetic interaction [J = +4.93(2) cm−1, g = 2.10(1) and Θ = −0.567(5) K]. © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.