Magnetic and EPR Spectroscopic Investigations on a Ferromagnetic Coupled Trinuclear Cu(II) Complex

Magnetization measurements and X‐band EPR investigations on the trimeric exchange coupled Copper(II)‐complex [(Cu3(C6H5CO2)4{(C )2NC2H4O}2(CH3OH)2] are reported. The field dependence of the magnetization at 3.7 K is consistent with a quartet ground state and proofs that ferromagnetic exchange coupling is operative between adjacent Cu(II) – centres in the trimeric molecule. – A strong temperature dependent variation of the g value from geff ≈︁ 4.3 at liquid helium temperature to geff ≈︁ 2.6 at room temperature was observed in the EPR experiment. Different explanations for the g shift are discussed.