Two novel complexes of Eu(III) and Tb(III) with mixed oxydiacetate (ODA) and 1,10-phenanthroline (phen) ligands and a Tb(III) complex with homoleptic ODA were prepared and their crystal structures were determined: [Eu(ODA)center dot(phen)center dot 4H(2)O]Cl center dot 5H(2)O, monoclinic, P2(1)/n, a=12.3197(12) angstrom, b=16.7992(17) angstrom, c=12.6754(10) angstrom, beta = 107.98](8)degrees, V=2495.2(4) angstrom(3), Z=4, R(\F\)=0.0324 for 5728 data; [Tb(ODA)center dot(phen)center dot 4H(2)O]Cl center dot 5H(2)O monoclinic, P2(1)/n, a=12.2846(13) angstrom, b = 16.7560(14) angstrom, c = 12.6681(11) angstrom, beta = 108.144(8)degrees, V = 2478.0(4) angstrom(3), Z = 4, R(\F\) = 0.0279 for 4364 data; Na-3[Tb(ODA)(3)]center dot 8H(2)O monoclinic, Cc, a = 15.751(3) angstrom, b = 9.8030(14) angstrom, c = 18.189(4) angstrom, beta = 105.513(15)degrees, V = 2706.2(9) angstrom(3), Z = 4, R(\F\) = 0.0406 for 3435 data. In these structures, the rare earth ions satisfy nine-coordination via binding to tridentate ODA, bidentate phen or water molecules. The geometry of the nine-coordinate polyhedron is discussed in terms of the dihedral angle and the mean plane. Photoluminescence (PL) and excitation spectra of Eu(III) and Tb(III) complexes with mixed ODA and phen ligands and with homoleptic ODA are reported. The complexes of [Eu(ODA)center dot(phen)center dot 4H(2)O](+) and [Tb(ODA)center dot(phen)center dot 4H(2)O](+) excited by UV light produce very bright red and green emissions, respectively, via the nonradiative energy-transfer from phen to the metals. For [Eu(ODA)center dot(phen)center dot 4H(2)O](+) and [Tb(ODA)center dot(phen)center dot 4H(2)O](+), the quantum yields of the sensitized luminescence (Q = 6.6 and Q = 75.7%, respectively) are much greater than those of the nonsensitized luminescence (Q = 2.0 and Q = 21.0%, respectively). (C) 2005 Elsevier B.V. All rights reserved.