Three coordination compounds [Mn3(dmb)6(H2O)4(4, 4′-bpy)3(EtOH)]n (1) and [M(dmb)2(pyz)2 (H2O)2] [MII = Co (2), Mn (3)] (Hdmb = 2, 6-dimethoxybenzoic acid, 4, 4′-bpy = 4, 4′-bipyridine, pyz = pyrazine) were synthesized and characterized by single-crystal X-ray diffraction analysis. Compound 1 consists of infinite 1D polymeric chains, in which the metal entities are bridged by 4, 4′-bpy ligands. There are four crystallographically independent MnII atoms in the linear chain with different coordination modes, which is only scarcely reported for linear polymers. The isostructural crystals of 2 and 3 are composed of neutral mononuclear complexes. In crystal the complexes are combined into chains by intermolecular O–H···N hydrogen bonds and π–π interactions between antiparallel pyrazine molecules.