Synthesis, Crystal Transformation And Luminescent Properties Of L-dbta Rare Earth Complexes

Two series L-dibenzoyl tartaric acid (L-DBTA) lanthanide coordination polymers,namely,{[Ln₂(L-DBTA)₃(CH₃OH)_x(H₂O)_y]·zH₂O}_n(Ln=La (1a), Ce (2a), Pr (3a) andNd (4a), x≠y=3or4and z=2or5) and{[Ln(L-DBTA)₂(CH₃OH)₂(H₂O)₂]·Et₃NH·2H₂O}_n(Ln=La (1), Ce (2), Pr (3), Nd (4),Gd (5) and Lu (6), Sm (7), Eu (8), Tb (9), Sm_0.33Eu_0.35Tb_0.32(10)), and a series Ln-Smbinary complexes {Et₃NH[Sm_xLn_y(L-DBTA)₂(CH₃OH)₂(H₂O)₂]·2H₂O}_n(Ln=La (11),Ce (12), Pr (13), Nd (14), Gd (15), Dy (16), Ho (17), Er (18), Yb (19), Lu (20); x=0.48⁰.54, y=0.46⁰.52) were synthesized by reactions of L-DBTA with LnCl₃·6H₂O,respectively.The molecular structures of complexes1a–4a and1–10were determinated byX-ray single crystal diffraction analysis. Complexes1a–4a were one-dimensionalinfinite "ladder" type chain, but1–10were one-dimensional infinite linear chain.Complexes1a–4a could be irreversible transformed to the crystals of complexes1–4under agitation. As a result, the crystal system changed from monoclinic toorthorhombic space and the center of lanthanide ions changed into the eight-coordinatedfrom nine, this SCSC transformation resulted in the change of the characteristeric NIRluminesence of Nd³⁺ion from complexes4a to4.Luminescent spectra revealed that7,8and9emits three primary colors of blue,green and red light, respectively. Strikingly, coordination polymer10incorporating withthree different lanthanide ions, e. g. Sm³⁺, Eu³⁺and Tb³⁺ions emits tunable color orwhite light by exciting at different wavelengths. Solid-state measurements of complexes11–20behavior demonstrated that except for the Ce³⁺and Er³⁺ions, the other rare earthions (La³⁺, Pr³⁺, Nd³⁺, Gd³⁺, Dy³⁺, Ho³⁺, Yb³⁺, Lu³⁺) which acted as "antenna" betweensamarium ion and the organic ligands were introduced in the Ln-Sm systems weresuccessful in sensitizing samarium ion emission.