Synthesis of co(II), Ni(II) and Cu(II) complexes from schiff base ligand and reactivity studies with thermosetting epoxy resin

E-mail: shivananda_kn@yahoo.com (K.N. Shivananda)Received November 23, 2010, Accepted March 24, 2011A hybrid thermosetting maleimido epoxy compound 4-(N-maleimidophenyl) glycidylether (N-MPGE) con-taining Co(II), Ni(II) and Cu(II) ions was prepared by curing N-MPGE and tetradentate Schiff base Co(II),Ni(II) and Cu(II) complexes. The curing polymerization reaction of N-MPGE with metal complexes as curingagents was studied. The cured samples were studied for thermal stability, chemical (acid/alkali/solvent) andwater absorption resistance and homogeneity of the cured systems. The tetradentate Schiff base, 3-[(Z)-2-piperazin-1-yl-ethylimino]-1,3-dihydro indol-2-one was synthesized by the condensation of Isatin (Indole-2, 3-dione) with 1-(2-aminoethyl)piperazine (AEP). Its complexes with Co(II), Ni(II) and Cu(II) have been synthe-sized and characterized by microanalysis, conductivity, Uv-Visible, FT-IR, TGA and magnetic susceptibilitymeasurements. The spectral data revealed that the ligand acts as a neutral tetradentate Schiff base andcoordinating through the azomethine nitrogen, two piperazine nitrogen atoms and carbonyl oxygen. Key Words : Isatin, Schiff base, Epoxy resin, Curing, EpichlorohydrinIntroductionIsatin and its derivatives are special members in the Schiffbase family. The simple isatin based Schiff base compoundshaving, acyl, aroyl and heteroacroyl Schiff bases have addi-tional donor sites >C=O, >C=N-, etc. These donor sitesmake them more flexible and versatile. This versatility hasmade them good chelating agents that can form a variety ofcomplexes with various transition and inner transition metalsand has attracted the attention of many researchers.