Synthesis and characterization of nickel(II) complexes with three potentially hexadentate Schiff-base ligands and polyamines: X-ray crystal structure determination of one nickel(II) complex

Three new potentially hexadentate N4O2 Schiff-base ligands (H2L1, H2L2 and H2L3) were prepared from the reaction of the polyamines N,N′-bis(2-aminophenyl)-1,2-ethanediamine (L1), N,N′-bis(2-aminophenyl)-1,3-propanediamine (L2) and N,N′-bis(2-aminophenyl)-1,4-butanediamine (L3), respectively with salicylaldehyde. Reaction of the Schiff bases with Ni(II) salts in the presence of N(Et)3 gave the neutral complexes [NiL4], [NiL5] and [NiL6]. Ni(II) complexes of the polyamines were also prepared. One of complexes [Ni(L1)(MeCN)2](ClO4)2·MeCN has been characterized through X-ray diffraction methods.