ESR and optical study of Cu2+-doped bis-(5,5′-diethylbarbiturato)bis picoline Zn(II)

Abstract

ESR studies were conducted on Cu2+-doped bis-(5,5′-diethylbarbiturato)bis picoline Zn(II). Two Cu2+ lattice sites, Cu2+(I) and Cu2+(II), were identified. These sites exhibit two sets of four hyperfine lines in all directions. The g factor and hyperfine splitting were calculated from ESR absorption spectra: gx = 2.0201 ± 0.002, gy = 2.0900 ± 0.002, gz = 2.1634 ± 0.002, Ax = (30 ± 2) × 10−4 cm−1, Ay = (40 ± 2) × 10−4 cm−1 and Az = (154 ± 2) × 10−4 cm−1. It was found that Cu2+ enters the lattice substitutionally. The ground-state wavefunction of the Cu2+ ion in this lattice was determined from the spin Hamiltonian constants obtained from the ESR studies. With the help of an optical absorption study, the nature of the bonding in the complex is also discussed.