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

Two novel lanthanum–tartrate complexes exhibiting distinctive new topologies, namely [La(TTA)1.5(H2O)]·H2O (1) and [La2(TTA)3(H2O)3]·2H2O (2) (H2TTA = tartaric acid), respectively, were obtained by the reactions of the lanthanum-oxide with corresponding H2TTA under hydrothermal conditions. In complex 1, the 2D layer consisted of μ4-ligands and four-connected La(III) centers is the first example of uni-nodal net of (42.64) topology. The 2D layers are further connected by μ2-TTA2− ligands to give a 3D (42.64)(42.67.8) topological structure. Complex 2 is a new 3D unprecedented five-nodal net of (4.62)(4.64.84.10)(4.64.8)(4.82)(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 H2TTA ligands.