Crystal structure, magnetic and electrochemical properties of five-coordinate copper (II) complexes with 1,10-phenanthroline-5,6-dione

摘要

Three new five-coordinate Cu-II complexes, [Cu(tpy)(phen-dione)](PF6)(2), [Cu(phen)(phen-dione)Cl]PF6 and [Cu(bpy)(phen-dione)Cl]PF6(tpy=2,2';6',2 ''-terpyridine, phen=1,10-phenanthroline and phen-dione=1,10-phenanthroline-5,6-dione) have been prepared and characterized by elemental analysis, IR and U-V-Vis spectroscopies and cyclic voltammetry. The complex of [Cu(tpy)(phen-dione)](PF6)(2) Crystallized with one molecule of acetonitrile. The ORTEP drawing of [Cu(tpy)(phen-dione)](PF6)(2)center dot CH3CN shows that the coordination geometry around Cu-II is a distorted trigonal-bipyramid. Due to the steric hindrance of PF6- in the unit cell, the tpy ligands in each complex cation cannot interact in a pi-pi fashion. The effective magnetic moment (mu(eff)) of the complexes was measured by the Evans method. The cyclic voltammograms at Pt disk electrode for these complexes display only one reversible Cu(II)/Cu(I) redox couple. (C) 2007 Elsevier B.V. All rights reserved.