Absorption- and Excitation-Modulated Luminescence of Pr(3+), Nd(3+), and Lu(3+) Compounds with Dianions of Tetrafluoroterephthalic and Camphoric Acids

[Image: see text] The luminescence of coordination polymers of Pr(3+), Nd(3+), and Lu(3+) with tetrafluoroterephthalate and camphorate, [Ln(2)(Fbdc)(3)(DMF)(2)(H(2)O)](2) (Ln = Pr, Nd, Lu) and [Ln(2)(Camph)(2)(NO(3))(2)(MeOH)](4) (Ln = Pr, Nd, Lu), was studied. Ligand-centered and/or metal-centered emissions appear, which depend on the excitation wavelength, ultimately allowing the emitted light color to be adjusted. Low-efficiency ligand-to-metal energy transfer leads to a difference between the excitation spectra of the tetrafluoroterephthalate- and camphorate-Pr(3+) compounds, arising from a primary filtering effect on the ligand-centered excitation, by Pr(3+) absorption. A secondary inner filter effect significantly changes the shape of the luminescence band, allowing a wide variation in the emission color, producing, for instance, a purple color, which is not the normal spectral emission. The low-efficiency energy transfer renders tetrafluoroterephthalate and camphorate ineffective as traditional “antenna” ligands for Pr(3+) and Nd(3+).