Four Cu(II) complexes [CuLH 2 O](ClO 4 ) 2 , 1; [CuLCl]Cl.H 2 O, 2; [CuLBr] 2 (Cu 3 Br 5 ), 3; and [CuLH 2 O](NO 3 ) 2 , 4;where L = tetradentate semicarbazone ligand, have been synthesized and characterized by elemental analysis, FT-IR and UV-Vis. The structures of compounds 1 and 3 have been determined by single-crystal X-ray diffraction analyses. In mononuclear 1, the semicarbazone, L acts as a tetradentate neutral ligand and a water molecule also coordinates to the Cu atom. There are two independent [CuL(H 2 O)] 2+ cations and four perchlorate anions in the crystallographic asymmetric unit. One of the cations has a weak interaction between its Cu atom and a O atom of an adjacent perchlorate anion. The structure of 3 contains two independent [CuLBr] + cations and a (Cu 3 Br 5 ) 2− anion. The coordination geometry around the cation's Cu(II) ion is five-coordinated square pyramidal, with L acting as a tetradentate neutral ligand and with a Br at the apical position. The Cu 3 Br 5 2− anions link to one another to form an infinite one-dimensional (Cu 3 Br 5 2− ) n chain. Furthermore, the Hirshfeld surface analyses and the 2D fingerprint plot have been discussed.