Conformational flexibility of 2,6-bis(pyrazol-1-ylmethyl)pyridine (L ~5) in [(L~5)Co~(II)(H_2O) _3]Cl_2 and [(L~5)Ni~(II)(H _2O)_2Cl]Cl·H_2O. Molecular structures and non-covalent interactions

摘要

Using a non-planar tridentate ligand 2,6-bis(pyrazol-1-ylmethyl)pyridine (L~5) two new coordination complexes [(L~5)Co ~(II)(H_2O)_3]Cl_2 (1) and [(L ~5)Ni~(II)(H_2O)_2Cl]Cl·H _2O (2) have been synthesized and structurally characterized. Complex 1 has N_3O_3 distorted octahedral environment around Co ~(II) with coordination by L~5 (two pyrazole and a pyridine nitrogen in a facial mode) and three water molecules. Complex 2 has N _3O_2Cl distorted octahedral geometry around Ni~(II) with meridional L~5 coordination, two water molecules, and a Cl ~- ion. Analysis of the crystal packing diagram reveals the involvement of solvent (water as metal-coordinated and as solvent of crystallization) and counteranion (Cl~-) to play significant roles in generating 1D chains, involving O-H···Cl, and O-H···O interactions.