Syntheses, structures, and luminescence of novel lanthanide complexes of tripyridylamine, N,N,N′,N′-tetra(2-pyridyl)-1,4-phenylenediamine and N,N,N′,N′-tetra(2-pyridyl)biphenyl-4,4′-diamine

Two novel blue luminescent bridging ligands N,N,N 'N ' -tetra(2-pyridyl)-1,4-phenylenediamine (tppd) and N,N,N ' ,N ' -tetra(2-pyridyl)-1, 1 -biphenyl-4,4 ' -diamine (tpbpd) have been synthesized. Several novel lanthanide complexes containing 2,2 ' ,2 " -tripyridylamine (2,2 ' ,2 " -tpa), 2,2 ' ,3 " -tpa, tppd, or tpbpd ligands have been synthesized and characterized structurally, which include Pr(hfa)(3)(2,2 ' ,2 " -1pa), 1, Ln(tmhd)(3)(2,2 ' ,3 " -tpa), 2 (Ln = Dy, 2a; Eu, 2b; Tb, 2c; Sm, 2d), [Eu(tmhd)(3)][Pr(hfa)(3)](2,2 ' ,3 " -tpa), 3, [Pr(hfa)(3)](2)(tppd), 4, and [Ln(hfa)(3)](2)(tpbpd), 5, where Ln = Pr (5a), Eu (5b), tmhd = 2,2,6-tetramethyl-3,5-heptanedionato, and hfa = hexafluoroacetylacetonate. The Dy(III), Eu(III), and Tb(III) complexes display a bright photoluminescence, which can be achieved by either a: direct excitation process or an indirect excitation process. Compounds 2a-2d can be sublimed readily.