Abstract: The lowest triplet state energies of phthalic acids were determined by measuring the luminescence spectra of their corresponding gadolinium complexes as model compounds. According to the energy match principle, then a series of terbium homopolynuclear and heteropolynuclear complexes with phthalic acids were synthesized and characterized. The luminescence properties of terbium complexes and the influences of inert rare earth ions(La³⁺, Gd³⁺, Y³⁺)on the luminescence properties of these complexes have been studied.

Key words: europium, terbium, lanthanum, gadolinium, yttrium, phthalic acid, complex, synthesis, luminescence property