The coupling of carbon dioxide and epoxides by phenanthroline derivatives containing different Cu(II) complexes as catalyst

A series of the mononuclear Cu(II) metal complexes containing the ligand Bdppz [(9a,13a-dihydro-4,5,9,14-tetraaza-benzo[b]triphenylene-11-yl)-phenyl-methanone] (L1) and Aqphen [(12,17-dihydronaphthol[2,3-h]dipyrido[3,2-a:2′,3′-c]-phenazine-12,17-dione)] (L2) were synthesized and used as catalyst for the coupling of carbondioxide and liquid epoxide which served as both reactant and solvent. The Cu(II) complexes were characterized by FT-IR, UV-Vis, elemental analysis, melting point, mass spectra, molar conductivity measurements and magnetic susceptibility techniques. The reaction of the Bdppz (L1) and Aqphen (L2) ligands in a 1:1, 1:2 or 1:3 mole ratio with CuCl2·2H2O afforded ionic Cu(II) complexes in the presence of Et3N. The catalytic results shown that the mononuclear complex [Cu(L2)Cl2] (6) has the best effective activities than the other mononuclear Cu(II) complexes for the formation of cyclic organic carbonates from carbon dioxide.