Mixed‐ligand Complexes with 2,6‐Pyridinedicarboxylato(2‐) and 4,7‐Diphenyl‐1,10‐Phenanthroline Ligands, [MII(pdc)(DPphen)(H2O)]·H2O (M = Co or Cu). Synthesis,Crystal Structures and Properties

Iso‐type [M^II(pdc)(DPphen)(H₂O]·H₂O compounds (M = Co or Cu, pdc = 2,6‐pyridinedicarboxylato(2‐) ligand and DPphen = 4,7‐diphenyl‐1,10‐Phenanthroline) were synthesized and studied by X‐ray diffraction, thermal and spectral methods. The N,N′‐equatorial bidentate DPphen‐copper(II) chelation imposes a mer‐N(equatorial)+O₂(apical) conformation to pdc in the coordination polyhedron (type 4+1+1). In the Co(II) derivative, the coordination is of type 1+2+2+1 because of a lesser Jahn‐Teller distortion. In the crystals, π,π‐interligand interactions between phen ligands connect the complex molecules in multi‐stacked chains. Aqua···O(carboxyl) H‐bonding interactions reinforce the stacked chains and build double chains in 1D supramolecular structures parallel to the a axis. Non coordinated water connect these structures by H‐bonds.