Coordination polymers of manganese(II) and cobalt(II) of a flexible tetradentate pyridine amide ligand: 1D zigzag network and non-covalent interactions

Synthesis and crystal structure of two coordination polymers of composition [MnII(H2bpbn)1.5][ClO4]2 · 2MeOH · 2H2O (1) and [CoII(H2bpbn)(H2O)2]Cl2 · H2O (2) [H2bpbn = N,N′-bis(2-pyridinecarboxamido)-1,4-butane], formed from the reaction between [Mn(H2O)6][ClO4]2/CoCl2 · 4H2O with H2bpbn in MeCN, are described. In 1 each MnII ion is surrounded by three pyridine amide units, providing three pyridine nitrogen and three amide oxygen donors. Each MnII center in 1 has distorted MnN3O3 coordination. In 2 each CoII ion is coordinated by two pyridine amide moieties in the equatorial plane and two water molecules provide coordination in the axial positions. Thus, the metal center in 2 has trans-octahedral geometry. In both 1 and 2, the existence of 1D zigzag network structure has been revealed. Owing to π–π stacking of pyridine rings from adjacent layers 1 forms 2D network; 2 forms 2D and 3D network assemblies via N–H⋯Cl and O–H⋯Cl secondary interactions. Both the metal centers are high-spin.