Diversity in the reactions of unsymmetric dinucleating Schiff base ligandswith Cu-II and Ni-II

A diversity of reaction products have been found in the reactions of two re lated unsymmetrical Schiff base dinucleating ligands, HL1 and HL2, derived from 3-chloromethyl-5-methylsalicylaldehyde 1, with copper(II) and nickel(I I) salts. The ligands remain intact in the copper(II) complexes to give the homodinuclear complexes [(Cu2LBr3)-Br-1] 2 and [Cu2L2(OH)(ClO4)]ClO4 3, th e crystal structures of which have been solved. The reactions of HL1 and HL 2 with nickel perchlorate led to hydrolysis of the imine bond. With HL1 the homodinuclear complex [NiLA(OH2)](2)[ClO4](2). 4H(2)O was formed and with HL2 hydrolysis was followed by elimination of C2H4 from the terminal NEt2 o f the iminic side arm to leave an NHEt group and the dinuclear complex [NiL C(OH2)](2)[ClO4](2). 3CH(3)OH. The crystal structures of the two nickel com plexes are also reported.