The engineering of metal-organic materials with specific properties using molecular building blocks approach is possible only by understanding the interplay of different interactions involved in selfassembly processes. Design strategies employing simultaneously coordination bonds, hydrogen bonds, and π-π stacking interactions in inorganic crystal engineering are mostly not well documented. [1]. From a crystal engineering perspective, one of the advantages of using transition metal ions is that the shape of the main building block can be controlled by way of organic ligandbound metal-containing modules in directions dictated by the coordination geometry of the metal center. Here we present the structures of two novel copper(II) complexes, [Cu2(acac)2(NO3)(dpp)(H2O)]NO3 (1) and [Cu(acac)(NO3)(dpp)] (2), with aromatic multifunctional ligand 2,3-bis(2-pyridyl)-pyrazine (dpp), which may adopt both chelating and bis(chelating) coordination modes, and thus has the ability to form mononuclear as well as di- and polynuclear complexes and acetylacetonate (acacH). Compound 1 crystallizes in the monoclinic system, space group P21/c, a = 14.346 Å, b = 12.168 Å, c = 15.924 Å, β= 95°. The dpp ligand in 1 coordinates in a chelate mode to two copper(II) ions and bridge them in dimeric entity as shown in Figure 1a. The Cu(II) atoms adopt a square pyramidal N2O3 geometry in which two N atoms of chelating dpp and two O atoms of chelating acac construct the equatorial plane. The apical position in the vertex of pyramid of two metals is differ and occupied by NO3 anion (Cu1) and water molecule (Cu2). Another inter-sphere NO3 anion compensates the positive charge of the dinuclear complex. The structure of 2 reveals a mononuclear neutral complex (Fig. 1b). This compound crystallizes in the monoclinic system, space group P21/n, a = 12.968 Å, b = 10.688Å, c = 13.917 Å, β= 93.47 . The conformation changes in dpp ligand and intermolecular interactions in the crystals of these complexes will be discussed.figureb Fig.1. A view of 1 (a) and 2 (b) complexes Acknowledgement. Financial support was provided by the Swiss National Science Foundation (SCOPES IZ73Z0_127925). [1] H. W. Roesky, M. Andruh. Coordination Chemistry Reviews 236 (2003) 91-119.