Crystal structure of a new homo trinuclear Ni(II) complex with μ-cyanoacetato bridge

Abstract

Trinuclear Ni(II) complex / Schiff bases / X-ray diffraction / Single crystal structure analysis / Thermal analysis Abstract. Ni(II)-Ni(II)-Ni(II) homo-trinuclear linear complex was prepared using bis-N,N 0 (2-hydroxybenzyl)-1,3-propanediamine in DMF (dimethyl formamide) medium. m-bridges between metal nuclei are formed using formate, acetate, chloroacetate and benzoate ions. The structure of the homo-trinuclear complex was determined with X-ray diffraction method. It was found that the terminal Ni(II) ions have a N 2 O 4 coordination sphere and central Ni(II) ion has a O 6 octahedral coordination sphere. The chelate ring, formed by the coordination of terminal Ni atoms and aminic nitrogen atoms, was found to have a chair conformation. The complexes were elucidated by the use of thermogravimetry and differential thermal analysis method. In acetate, chloroacetate, cyanoacetate and benzoate containing complexes thermal dissociation of DMF took place first while in formate containing complex it was observed that formate bridges and the complex degraded together with the dissociation of DMF moiety. It was observed that the thermal stability of carboxylate m-bridge affects the thermal stability of the homo-nuclear complex. The average bond energies of coordinated DMF molecules were determined and these coordinative bond energies were found to be in the dimension of that of hydrogen bonds.