Single crystal EPR and polycrystalline 1H NMR study of a ferromagnetically coupled dinuclear copper(II) complex in [P(C6H5)4][CuCl3]

EPR has been observed in a single crystal of [P(C6H5)4][CuCl3] at room temperature. The spectrum was characteristic of a spin one system, indicating that the copper(II) ions are pairwise coupled in the crystal. The present results agree fairly well with a previous study by Bencini etal. (Inorg. Chem., 1985, 24, 704). From the temperature dependence of the 1H NMR spin–lattice relaxation time, the copper dimer Cu2Cl62- is suggested to have a triplet ground state in accordance with an analysis of the magnetic susceptibility measurements by Estes etal. (Inorg. Chem., 1978, 17, 3657). The exchange interaction between the nearest triplet-state dimers is estimated to be of the order of 10-1 K.