Alkaline Ion-Modulated Solid-State Supramolecular Organization in Mixed Organic/Metallorganic Compounds Based on 1,1′-Ethylenebis(4-aminopyridinium) Cations and Bis(oxamate)cuprate(II) Anions

Abstract

Three new coordination compounds of formula (edap)2[Cu(opba)]2·4H2O (1), (edap)[{Na2(H2O)4}{Cu2(opba)2}]·2H2O (2), and (edap)[{K2(H2O)2}{Cu2(opba)2}]·3H2O (3) (edap = 1,1′-ethylenebis(4-aminopyridinium) and opba = 1,2-phenylenebis(oxamate)) were synthesized through the metathesis reaction involving A2[Cu(opba)] (A = Li+, Na+, and K+) and (edap)Cl2·2H2O. Crystal structures of 1–3 and edap(IO3)2·4H2O compound were elucidated by single crystal X-ray diffraction. Compounds 1–3 are built up from dinuclear copper(II) entities, {[Cu(opba)]2}4– with an asymmetric bis(monatomic oxygen) bridge resulting from the parallel “out-of-plane” disposition of the planar mononuclear [Cu(opba)]2–. They possess distinct supramolecular arrangements of varying dimensionality (nD with n = 0 (1), 1 (2), and 2 (3)) in the solid state depending on the nature of the coordinated alkaline ion present alongside edap2+ counterions. While the {[Cu(opba)]2}4– building blocks are well-isolated in 1, they form either double chains or corrugated layers due to the coordination of the Na+ or K+ ions in 2 and 3, respectively. Magnetic properties of 1–3 show a very weak antiferromagnetic coupling between the CuII ions through a double monatomic (μ-O) bridge (−J = 1.63(9) (1), 2.29(2) (2), and 1.65(3) cm–1 (3)), the Hamiltonian being defined as H = −(S1·S2) + g βH(S1 + S2).