Magnetic and spectroscopic investigations of tetra(4-t-butyl)phthalocyano complexes of cobalt(II) and copper(II)

Abstract

The tetra(4-t-butyl)phthalocyanine derivatives of Co and Cu have been studied by ESR spectroscopy in solution owing to their solubility in polar and non-polar solvents. The cobalt complex gives a well-resolved EPR spectrum in toluene glass at 77 K with g‖ = 2.018, g_⊥ = 2.785, A‖ = 0.0155 cm^-1, A_⊥ = 0.0208 cm^-1, P = 0.0201 cm^-1 and K = 0.0079 cm^-1. Although the low-field lines due to A_⊥ seem a lot more broadened than the high-field ones due to A‖, both sets have been shown to have highly M_I-dependent linewidths. The experimental data for g and A available in the literature have been plotted and compared with McGarvey's theoretical equations. The copper complex in toluene glass at 110 K gives a well-resolved EPR spectrum at Q-band frequency with g‖ = 2.163, g⊥ = 2.048, A‖ = 0.0212 cm^-1 and A_⊥ = 0.0032 cm^-1.