One-Pot Synthesis, Structure, and Unusual Luminescence of Novel One-Dimensional Lanthanide(III) Tetramethoxyborates.

Detailed studies of formation, structure, and luminescence characteristics of novel ionically linked sinusoidal chains of [{Na}{(sal)(3)Ln(B(OCH(3))(4))Ln(sal)(3)}](n)() [Ln = Nd, Sm, Tb-Lu, Y (4); Ln = Eu (5); Ln = Gd (6)] was undertaken to assess the versatility of tetramethoxyborate anions as consistent general synthons for one-dimensional materials. Crystal data for [{Na}{(sal)(3)Nd(B(OCH(3))(4))Nd(sal)(3)}](n)() [4(Ln = Nd)]: monoclinic; space group, C2/c (15), a = 20.884(2) Å, b = 12.454(1) Å, c = 37.663(5) Å, beta = 102.09(2) degrees, Z = 8; [{Na}{(sal)(3)Eu(B(O CH(3))(4))Eu(sal)(3)}](n)() (5): monoclinic; space group, C2/c (15), a = 20.846(2) Å, b = 12.460(1) Å, c = 37.365(4) Å, beta = 102.17(1) degrees, Z = 8. Europium luminescence from [{Na}{(sal)(3)Ln(1)(-)(x)()Eu(x)()(B(OCH(3))(4))Ln(1)(-)(x)()Eu(x)()(sal)(3)}](n)() [Ln = Eu (5); Gd (7-11), Y (12), Dy (13-18), Dy/Gd (19)] reveals the presence of defect Eu(3+) sites, possibly resulting from swapping regular Eu(3+) and Na(+) positions. Strong Eu(3+)-Eu(3+) electronic interactions result in multidimensional energy migration and a dynamic excitation energy-transport regime. Efficient thermally activated regular Eu(3+)-to-defect Eu(3+) back-energy transfer dominates at 297 K.