Abstract The thiosemicarbazide and hydrazide Cu (II) complexes,[Cu 3 L 2 1 (py) 4 Cl 2](1),[Cu (HL 2) py](2) and [Cu (HL 3) py](3),(H 2 L 1= 1-picolinoylthiosemicarbazide, H 3 L 2= N′-(2-hydroxybenzylidene)-3-hydroxy-2-naphthohydrazide, H 3 L 3= 2-hydroxy-N′-((2- hydroxy-naphthalen-1-yl) methylene) benzohydrazide) have been prepared and characterized through physicochemical and spectroscopic methods as well as X-ray ...