Mn(II)/Ni(II) Complexes Based on 5-Methyl-1H-pyrazole-3-carboxylic Acid: Syntheses, Structures, Electrochemical and Luminescent Properties

In the absence/presence of chelating N ancillary ligand, 2,2'-bipyridine (2,2'-bpy), treatment of 5-methyl-1H -pyrazole-3-carboxylic acid (H(2)MPCA) with corresponding Mn(II)/Ni(II) metal salts afforded two complexes, [Mn(HMPCA)(2)(H2O)(2)] (1) and [Ni(HMPCA)(2)(2,2'-bpy)]center dot 2H(2)O (2). In mononuclear complexes 1 and 2, each metal ion locates in a distorted octahedral geometry, and the HMPCA(-) ligands in 1 and 2 both act as a N, O-chelating ligand. In 1, by the function of intermolecular N-H center dot center dot center dot O and O-H center dot center dot center dot O hydrogen bonds, the independent [Mn(HMPCA)(2)(H2O)(2)] units are packed into a porous 3D supramolecular structure with 1D nanotube. In 2, the mononuclear components [Ni(HMPCA)(2)(2,2'-bpy)] and the lattice water molecules are interlinked via intermolecular O-H center dot center dot center dot O and NH center dot center dot center dot O hydrogen bonds, generating a 1D chainlike structure, which is linked to adjacent ones through intermolecular pi center dot center dot center dot pi interactions forming a 3D supramolecular architecture. The electrochemical and luminescent properties of complexes 1 and 2 have also been investigated. CCDC: 2033945, 1; 2033946, 2.