Synthesis and characterization of the dihydrosalpren ligand (H2L1) and of its trinuclear Ni(II) complex

The synthesis of the new unsymmetrical tetradendate Schiff ligand N-(2-hydroxybenzyl)-N′-(2-hydroxybenzylidene)-1,3-diaminopropane (H2L1) is reported. The ligand comprises two different coordination moieties: a rigid salicylaldimmine unit and a more flexible (2-hydroxybenzyl)-amino (hydrogenated salicylaldimmine) unit. The reaction of H2L1 with Ni(OAc)2·4H2O (1:1 molar ratio) leads to the spontaneous formation of a trinuclear complex with composition {[Ni(L1)OH2]2(OAc)2Ni}·2H2O, characterized by X-ray crystallography, where two [Ni(L1)] units act as O,O-bidentate chelate to a Ni(II) ion.