Molecular Design, Syntheses, Structures, Characterizations Research On A Series Of Lanthanide Complexes With Rigid And Flexible Multi-carboxylate Ligands

The molecular design, synthesis, structure and characteristic of lanthanide coordination polymers based on the assembly of rigid and flexible carboxylate-containing mixed ligands are our mainly work. The aim is to research the structural variety of lanthanide-carboxylate coordination polymers, and discuss novel sub-structural unit and the design and synthesis new coordination polymers with novel structures. 14 lanthanide coordination polymers were synthesized by choosing different organic ligands. In the synthesis aspect, we study how to affect the structures on metal ions, organic ligands, template and pH value. The structures of complexes 1-14 are determined by the X-ray crystal diffractometer. All complexes are mainly characterized by elemental analysis and IR spectrum. The thermogravimetric analysis and photoluminescent properties were discussed. This paper, we synthesize 14 complexes as following:[Tb₂(Suc)_0.5(BC)₃(OH)₂] (1) [Eu₂(Suc)_0.5(BC)₃(OH)₂] (2)[Sm₂(Suc)_0.5(BC)₃(OH)₂] (3) [Pr₂(Suc)_0.5(BC)₃(OH)₂] (4)[Pr(mal)(ox)_0.5(H₂O)₂]·2H₂O (5) [Nd(mal)(ox)_0.5(H₂O)₂]·2H₂O (6)[La(mal)(ox)_0.5(H₂O)₂]·2H₂O (7) [Sm(suc)(ox)_0.5(H₂O)] (8)[Tb(suc)(ox)_0.5(H₂O)] (9) [Pr(suc)(ox)_0.5(H₂O)₂]·2H₂O (10)[KNd(suc)_0.5(ox)_1.5(H₂O)]·H₂O (11) [KEu(suc)_0.5(ox)_1.5(H₂O)]·H₂O (12)[KTb(suc)_0.5(ox)_1.5(H₂O)]·H₂O (13) [KGd(suc)_0.5(ox)_1.5(H₂O)]·H₂O (14) Note: H₂Suc=succinic acid; HBC=benzoic acid; H₂mal=maleic acid; H₂ox=oxalic acidMixed organic ligands (i) succinic acid and benzoic acid, (ii) maleic acid and oxalic acid, (iii) succinic acid and oxalic acid were chosen to construct lanthanide coordination polymers. In chapter three, infinite inorganic walls formed by lanthanide ions,μ₃-OH, and an edge-sharing "…Ln-O-C-O-Ln…" chain, which link to each other through the carbon atoms of the succinate anions and phenyl groups of the benzoic acid ligands, leading to a two-dimensional open framework structure. In chapter four, approximate 6.4×7.8 (?) rectangle channels were formed, and these channels were occupied by coordinated water and free water molecules and they could be anticipated as potential channel materials. In chapter five, we discuss that coordination modes of metal ions, and different mol ratio of mixed organic ligands play an effect on net structures of lanthanide coordination polymers. Three dimension complexes with novel structures were obtained. The paper layed a foundation for further design and synthesis of the system.