Synthesis and characterization of some novel copper(II) complexes with an optically active Betti base

Novel Cu(II) complexes with racemic as well as optically pure 1-(α-amino benzyl)-2-napthol, commonly known as Betti base, and its derivative 1-(α-pyrrolidinyl benzyl)-2-napthol have been synthesized. The general composition of all the isolated complexes, as determined by elemental analysis, thermal analysis and FAB mass spectra, is found to be Cu(L-H)2. The coordination of the ligand with metal has been confirmed by IR and ESR spectra of the complexes. The CD spectra of complexes with the S-form of the ligands exhibit a mirror image relationship with the CD spectra of the complexes with the corresponding R-form of the ligands. The Cu(II) complex with racemic Betti base has been characterized structurally. It crystallizes in the monoclinic space group P21/c. The complexes display quasi reversible redox behavior due to the Cu(II)/Cu(I) reduction process.

Graphical abstractNovel Cu(II) complexes with racemic Betti base crystallizes in a monoclinic space group P21/c. The CD spectra of complexes with S- form of Betti bases exhibit mirror image relationship with the corresponding R- form of the ligands. All complexes display a quasi reversible redox behavior due to the Cu(II)/Cu(I) reduction process.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Cu(II) reacts with Betti bases in 1:2 mole ratio to form Cu(L-H)2 complexes. ► Phenyl rings lye on opposite sides of molecular plane of racemic Cu(II) complex. ► The geometry of the other complexes is more distorted. ► Structure of chiral Cu(II) complexes has been proposed.