201403-28-3Relevant academic research and scientific papers
Synthesis and structural characterization of copper(I) and copper(II) complexes with an ambivalent phenanthroline-type ligand
Collin, Jean-Paul,Gavina, Pablo,Sauvage, Jean-Pierre,De Cian, Andre,Fischer, Jean
, p. 951 - 957 (2007/10/03)
The new phenanthroline ligand 2-(p-methoxyphenyl)-9-(5′-methylpyridin-2′-yl)-l,10-phenanthroline L has been synthesized and shown to form four-coordinate CuI (L)2 (1) and six-coordinate CuII(L)2 (2) complexes. Their structures have been determined by X-ray crystallography: (1) C50H38CuN6O2.BF4, triclinic, space group P1, a 12.924(3), b 14.567(4), c 12.649(3) A, α 105-57(2), β 107.68(2), γ 104.00(2)°; (2) C50H38CuN6O2.2PF6, monoclinic, space group P21/c, a 17.701(5), b 19.285(5), c 14.293(4) A, β 98.20(2)°. In solution, cyclic voltammetry measurements indicate for the copper(I) and copper(II) complexes a very fast rearrangement of the pyridine substituent with the change of the oxidation state. Surprisingly, the X-ray data show two different coordination modes for the ligand around the copper(1) ion, the 1,10-phenanthroline nucleus being either mono- or bi-dentate. In solution, since the 1H n.m.r. spectra obtained even at several temperatures display only one set of signals, it is proposed that a fast equilibrium takes place between two coordination modes of the phenanthroline.
