Synthesis, characterization of a novel calixarene having dipyridyl pendants and study of its complexes with Cu(II) and Co(II)

Two dipyridyl pendants were attached to the 1,3 positions of a calix[4]arene, with the purpose of having a ligand able to complex Cu(II) and Co(II). Indeed, the new ligand, fixed in its 1,3-alternate conformation, forms stable complexes with both Co(II) and Cu(II), as shown by UV-vis titrations carried out in acetonitrile. However, the data analysis clearly shows that the ligand forms with the two metal ions complexes having different stoichiometries.