Synthesis and spectroscopic studies of some transition metal complexes derived from bis-2-pyrazoline ligand

The present work focuses on the synthesis and spectroscopic studies of some metal complexes based on a novel bis-2-pyrazoline ligand; 5-(4-(1-carbamothioyl-5-(pyridin-3-yl)pyrazolidin-3-yl)phenyl)-3-(pyridin-3-yl)pyrazolidine-l-carbothioamide. This ligand was prepared via the cyclization reaction of 3-(4-((E)-3-oxo-3-(pyridin-3-yl)prop-1-en-1-yl)phenyl)-1-(pyridin-3-yl)prop-2-en-1-one with alkaline solution of thiosemicarbazide. The resulted 2-pyrazoline ligand was identified by the FT-IR, NMR and LC-MS spectroscopes, in addition to (C.H.N.S) elemental analyses. The complexes of Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) were prepared from their metal chlorides and ethanolic solution of the prepared ligand in 10% ammonia (mole ration 2:1 M:L). The octahedral geometry for all complexes was confirmed by atomic absorption, FT-IR, UV-Visible, magnetic moments and molar conductivity measurements. The thermal stability of the prepared complexes was confirmed by the thermal gravimetric analyses and the observed results indicated that the suggested chemical structure are in agreement with other data of elemental micro-analyses and flame atomic absorption spectroscopy.