A new terbium(III) complex Tb2(C15H11O3)6(phen)2 has been synthesized with 2-(4-methylben-zoyl)benzoic acid and 1,10-phenanthroline as ligands. Crystal data for the complex are as follows: monoclinic, space group P21/n, a = 15.0786(6), b = 13.5762(5), c = 22.9683(9) Å, β = 104.130(4)º, V = 4559.6(3) Å3, Dc = 1.540 g/cm3, Z = 2, μ(MoKα) = 1.615 mm-1, F(000) = 2136, the final R = 0.0528 and wR = 0.0740. The Tb(III) ion is coordinated by eight atoms to give a distorted square antiprism coordination geometry. The complex shows four fluorescen...