ESR study on some copper(Ⅱ)complexes of bis(4'-benzo-15-crown-5)

ESR measurements have been carried out for some copper(Ⅱ) complexes of bis(4'-ben-zo-15-crown-5) at 77 K.The results of ESR spectrometric titration indicated that the binuclear com-plexes were prepared in the present system.The binuclear complexes revealed characteristic ESRg-anisotropies (gZ

ESR study on some copper(II) complexes of bis(4′-benzo-15-crown-5)

ESR measurements have been carried out for some copper(II) complexes of bis(4′-benzo-15-crown-5) at 77 K. The results of ESR spectrometric titration indicated that the binuclear complexes were prepared in the present system. The binuclear complexes revealed characteristic ESR g-anisotropies (gZ<gX, gY) which are typical of the copper(II) complexes with a 3d ground state doublet. However, in this case, the innermolecular copper(II)-copper(II) spin interaction was not observed. ESR measurements also showed that a small amount of the sandwich type copper(II) complexes were formed in the presence of excess bis (4′-benzo-15-crown-5). A reasonable explanation was given for the ESR results.