文摘
The properties of Cu(II) and Co(II) complexes with oxygen- or nitrogen-containing macrocycles have been extensivelystudied; however, less attention has been paid to the study of complexes containing sulfur atoms in the firstcoordination sphere. Herein we present the interaction between these two metal ions and two macrocyclic ligandswith N2S2 donor sets. Cu(II) and Co(II) complexes with the pyridine-containing 14-membered macrocycles 3,11-dithia-7,17-diazabicyclo[11.3.1]heptadeca-1(17),13,15-triene (L) and 7-(9-anthracenylmethyl)-3,11-dithia-7,17-diazabicyclo[11.3.1]heptadeca-1(17),13,15-triene (L1) have been synthesized. The X-ray structural analysis of{[Co(ClO4)(H2O)(L)][Co(H2O)2(L)]}(ClO4)3 shows two different metal sites in octahedral coordination. The EPR spectraof powdered samples of this compound are typical of distorted six-coordinated Co(II) ions in a high-spin (S = 3/2)configuration, with the ground state being S = 1/2 (g1 = 5.20, g2 = 3.20, g3 = 1.95). The EPR spectrum of[Cu(ClO4)(L)](ClO4) was simulated assuming an axial g tensor (g1 = g2 = 2.043, g3 = 2.145), while that of[Cu(ClO4)(L1)](ClO4) slightly differs from an axial symmetry (g1 = 2.025, g2 = 2.060, g3 = 2.155). These resultsare compatible with a Cu(II) ion in square-pyramidal coordination with N2S2 as basal ligands. Single-crystal EPRexperiment performed on [Cu(ClO4)(L1)](ClO4) allowed determining the eigenvalues of the molecular g tensorassociated with the copper site, as well as the two possible orientations for the tensor. On the basis of symmetryarguments, an assignment in which the eigenvectors are nearly along the Cu(II)-ligand bonds is chosen.
