Crystal structures, electronic absorption and reflectance spectral behaviors, and electrochemical properties of five-coordinated chlorocopper(II) complexes with 5,6-disubstituted-1,10-phenanthroline
摘要:
The five-coordinated geometries around the Cu(II) centers in [CuCl(dmphen)(2)]PF6 (1; dmphen = 5,6-di-methyl-1,10-phenanthroline) and [CuCl(phendione)(2)]PF6 (.) H2O (2; phendione = 1,10-phenanthroline-5,6-dione) are distorted square-pyramidal in contrast to the distorted trigonal-bipyramidal [CuCl(phen)(2)]PF6 (phen = 1, 10-phenanthroline), reflecting introductions of substituents into the 5- and 6-positions on phen. It has been found that these geometries in I and 2 are considerably dependent on the interactions between the pi-electronic systems of the phen frameworks. The diffuse reflectance spectra significantly reflect geometrical differences of 1 and 2 from [CuCl(phen)(2)]PF6. The electronic absorption spectra suggest that the geometries of 1 and 2 in solution are similar to those in the crystalline state, while the geometry of [CuCl(phen)2]PF6 seems to be changed from distorted trigonal-bipyramid to square-pyramid. The electrochemical experiments indicate that the redox properties of these complexes are appreciably influenced by the electronic characters of the substituents on the phen frameworks. (C) 2002 Elsevier Science Ltd. All rights reserved.