Reactions of MCl2 (M = Mg, Ca, Sr, Ba) and a4-ptz (a4-ptz = 5-[N-acetato (4-pyridyl)]tetrazolate) potassium salt in water, respectively, and produced four new complexes [Mg(H2O)(6)] center dot (a4-ptz)(2) center dot 2H(2)O (1), [Ca(a4-ptz)(2)(H2O)(2)](n) center dot 2nH(2)O (2), [Sr(a4-ptz)(2)(H2O)(2)]n center dot 2nH(2)O (3), [Ba-4(a4-ptz)(8)(H2O)(8)](n) center dot 4nH(2)O (4). These compounds were structurally characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. Compound 1 has mononuclear structure bearing distinct intermolecular hydrogen-bond interactions to form a three-dimensional supramolecular network. While compounds 2-4 have one-dimensional polymeric chains that are bridged by two water molecules linker, respectively. The luminescence properties of 1-4 were investigated at room temperature in the solid state. (C) 2008 Elsevier B. V. All rights reserved.