Two mononuclear complexes [Mn(5-methylpyrazole)(4)(N-3)(2)] (1) and [Ni(5-methylpyrazole)(4)(N-3)(2)] (2), as well as a novel one-dimensional coordination polymer [Co(3-methylpyrazole)(2)(5-methylpyrazole)(2)(tp)](n) (3) (tp = terephthalate), were characterized. The isostructural complexes, 1 and 2, display two-dimensional supramolecular networks formed by hydrogen bonds between the N-H groups of 5-methylpyrazoles and the end N atoms of the azide ligands and additional face-to-face d-d interactions of the 5-methylpyrazoles. For 3, tp-bridged one-dimensional chains assisted by intrachain hydrogen bonds among the N-H groups of methylpyrazoles and carboxylate oxygens are connected with the help of interchain C-H center dot center dot center dot O hydrogen bonds, leading to a two-dimensional structure. The intra- and interchain hydrogen bonds account for the coexistence of two unique coordination forms (5-methylpyrazole and 3-methylpyrazole) of methylpyrazoles in the same coordination sphere. Weak antiferromagnetic interactions coupled with the spin orbit coupling effect are operative in 3 through the tp ligands.