Abstract: The ESR spectra of the complexes of four kinds of n-amine with Cu(ClO₄)₂ have been investigated at 77K. The relative order of σbonding strength and ligand field splitting energies have been calculated by using the hyperfine coupling constants and g values. The results indicate that the σbonding strength increases with the lengthening of carbon chain in ligand molecules and starts to decrease in the ligand complex of n-valeramine. The bondingnature of amino groups is different from those of ammonia in these copper(Ⅱ)-n-amines complexes.

Key words: copper(Ⅱ)-n-amines complex, ESR,bonding parameters