The first metal chelate of un-substituted 2,6-pyridine-dicarboxamide (pdcam): synthesis, molecular and crystal structure, and properties of [CuII(pdc)(pdcam)] · 2H2O (pdc = 2,6-pyridine-dicarboxylato(2−) ligand)

A novel mixed-ligand copper(II) derivative with 2,6-pyridine-dicarboxylato(2−) ligand and its primary diamide derivative, namely 2,6-pyridine-dicarboxamide (pdcam), was synthesised and characterised by X-ray crystallography, and thermal, spectral and magnetic methods. The tridentate pdcam ligand is flexible enough to bind Cu(II) atom in a mer-N(equatorial) + O2(apical) conformation.