The electronic properties of trigonal bipyramidal complexes of the copper(II) ion

Abstract

The e.s.r. and electronic spectra and magnetic moments of Cu(NH₃)₂Ag(SCN)₃ and [Cu(tren)NCS]SCN (tren = 2,2′,2″-triaminotriethylamine) are reported and compared with the previously reported data for trigonal bipyramidal complexes of the copper(II) ion. Theoretical expressions for the g-values for a copper(II) ion in a trigonal bipyramidal configuration are derived and are shown to apply only to the Cu(NH₃)₂Ag(SCN)₃ complex. The energy levels ²E″ and ²E′ are shown to be separated by less than 2000 cm.^–1 and the magnetic moments of the trigonal bipyramidal complexes are in the range normally observed for copper(II) complexes with an orbitally non-degenerate ground state.