Auxiliary ligand-dependent assembly of several Ni/Ni-Cd compounds with N2O2 donor tetradentate symmetrical Schiff base ligand

Several low-dimensional Ni/Ni-Cd complexes containing the N2O2 donor tetradentate symmetrical Schiff base ligand bis(acetylacetone)ethylene-diamine (sy-H2L2), namely, [Ni(sy-L-2)](2)center dot HLa center dot ClO4 (2), (HLa)(2)center dot(ClO4)center dot(NO3) (3), [Ni(sy-L-2)X](2)](4,4'-bipy) (where L-a = 5,7-dimethyl-3,6-dihydro-2H-1,4-diazepine, X = ClO4 (4), X = NO3 (5), [Ni(sy-L-2)Cd(SCN)(2)](n) (6) and [Ni(sy-L-2)center dot Cd(N-3)(2)](n) (7), have been synthesized from [Ni(sy-L-2)](2)center dot H2O (1) Complex 2 is a three-component discrete assembly generated from it (HLa)(+) moiety bridged with a [Ni(sy-L-2)] unit and ClO4- anion. A solution containing complex 2 and Cd(NO3)(2) results in a mixture of 1 and 3. Further recrystallization of 1 and 3 with various auxiliary ligands provides coordination complexes 4-7 stabilized by weak hydrogen bonds in which 6 and 7 represent the first one-dimensional heteronuclear complexes based on the symmetric acacen-base Schiff base ligand.