Synthesis and Characterization of Tris(2,2′-bipyridine) and tris(1,10-phenanthroline) Copper(II) Hexafluorophosphate. Crystal Structure of the Phenanthroline Complex

The tris-(bidentate)chelate complexes [Cu(NN)(3)](PF6)(2) where NN=2,2'-bipyridine or 1,10-phenanthroline have been isolated as secondary products in the reaction between the dimers [{Cu(NN)}(2)(mu-OH)(2)](PF6)(2).2H(2)O and di-2-pyridylketone. The X-ray crystal structure of [Cu(phen)(3)](PF6)(2) showed a distorted octahedral C-2 geometry around the metal atom, with two Cu-N distances being much longer than the other four. Magnetic susceptibility measurements (in the 4.4-290K range) correspond, in both cases, to a d(9) configuration without significant magnetic interaction. A signal (g=2.102) was observed in the EPR spectrum of the bipy complex and the two axial components were resolved for the phen complex, with g(parallel to)=2.249, g(perpendicular to)=2.083 and A(parallel to)=137x10(-4) cm(-1). In this case also a signal at g=2.128 is observed.