A New phenoxido/trifluoroacetato bridged heterometallic Ni-2(II)-Cu-II derivative: Structure, EPR interpretation and DFT computation

Abstract

The trinuclear heterometallic Ni-2(II)-Cu-II complex, [Ni-2(L)(2)(CF3COO)(2)Cu] (1) is afforded incorporating a tetradentate Schiff base precursor, H2L [where H2L = N,N'-bis(salicylidene)-1,3-propanediamine]. In 1, the two terminal Ni-II atoms are linked to the central Cu-II by a syn-anti bridging trifluroacetate and a double phenoxido bridge, giving rise to a linear structure. The EPR spectra show that the trinuclear structure remains unchanged in non-coordinating solvents, whereas in DMF and DMSO the resonances of mononuclear Cu-II species with an axial symmetry and a well-resolved hyperfine structure are observed. DFT calculations reveal that the spin Hamiltonian parameters are g(z) 2.22 and A(z) 176.4 x 10(-4) cm(-1), which are in good agreement with the experimental values. The biological outcome of complex 1 on the viability of different human carcinoma cells are analyzed by MTT assay and the results suggest that it induces a decrease in cell-population growth with apoptosis