1 Synthesis and characterization of Zn(II), Cu(II), Co(II), Ni(II), Cd(II) and Ru(III) ions with a tridentate NNO thiazole derived Schiff base Ayman A. Abdel Aaziz a , Rania G. Mohamed b , Abdelmoneim A. Makhlouf b , Sherin A. Mosad b and Samir M. El-Medani b, * a Chemistry Department, Faculty of Science, Ain Shams University, 11566, Abbassia, Cairo, Egypt. b Chemistry Department, Faculty of Science, El-Fayoum University, 63514, El-Fayoum, Egypt. Abstract Thermal reaction of Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Ru(III) metal ions with a tridentate Schiff-base ligand(HL) derived from the condensation of 2-aminothiazole and 2- hydroxy-1-naphthaldehyde resulted in the formation of a series of six new metal complexes: [Co(HL) 2 Cl 2 ]; 1,[Ni(L)(CH 3 COO)(H 2 O)]; 2,[Cu(L) 2 ]; 3, [Zn(L) 2 ]; 4, [Cd(L)(CH 3 COO) (H 2 O)]H 2 O; 5, [Ru(L) 2 (H 2 O) 2 ]Cl; 6. The ligand and its complexes were characterized by means of elemental and thermal analyses along with molar conductance and magnetic moment measurements as well as different spectroscopic techniques. The ESR spectrum of Cu(II) complex indicated elongated and covalent character of octahedral environment. Keywords: Spectroscopic studies; Schiff base; Transition metal complexes, Thermal studies. *Corresponding author. Professor Dr. Samir M. El-Medani, Department of Chemistry, Faculty of Science, Fayoum University, El-Fayoum, Egypt. E-mail address: samirmedani20@gmail.com .