Two novel lanthanum-tartrate complexes with distinctive new topologies: Hydrothermal synthesis and crystal structures

摘要

Two novel lanthanum-tartrate complexes exhibiting distinctive new topologies, namely [La(TTA)_(1.5) ~(H_2O)]?H_2O (1) and [La_2(TTA)_3(H_2O)_3] ?2H_2O (2) (H_2TTA = tartaric acid), respectively, were obtained by the reactions of the lanthanum-oxide with corresponding H _2TTA under hydrothermal conditions. In complex 1, the 2D layer consisted of μ_4-ligands and four-connected La(III) centers is the first example of uninodal net of (4~2.6~4) topology. The 2D layers are further connected by μ_2-TTA~(2-) ligands to give a 3D (4~2.6~4)(4~2.6~7.8) topological structure. Complex 2 is a new 3D unprecedented five-nodal net of (4.6~2)(4.6~4.8~4.10)(4.6~4.8)(4.8 ~2)(6.3) topology, which is constructed by regular (6,3) nets. In both complexes, La(III) atoms act as rare five-connected topological blocks. The structural diversity of 1 and 2 was caused by the different chiralities of the starting H_2TTA ligands.