The crystal structures of two neodymium(iii) complexes with pyridine‐2, 6‐dicarboxylic acid

Structural Systematics for Lanthanide(III) Systems: Interactions of the Achiral Hexamminecobalt(III) Cation with Tris(dipicolinato)lanthanate(III) Anions

Extended structural studies, largely determinations at ~150 K, of the family of hydrates of [Co(NH3)6][Ln(dipic)3] (Ln = La–Lu, and Y; dipic = dipicolinate = pyridine-2,6-dicarboxylate) have provided detailed evidence of the nature of the interactions between the formally achiral cation and the chiral anions. They also provide a reference point for consideration of related systems incorporating chiral cations with and without the capacity to act as H-bond donors.

Two-Dimensional Layered Metal - Organic Frameworks of Lanthanum(III) Pyridine-2,6-dicarboxylate

Three two-dimensional (2D) LaIII metal–organic frameworks, {[La4(pda)6(H2O)8]·2H2O} n (1), {[La2(pda)3(H2O)4]·H2O} n (2), and {[La2(pda)2(H2O)5SO4]·2H2O} n (3) (pda = pyridine-2,6-dicarboxylate), have been synthesized under hydro(solvo)thermal conditions and characterized by means of X-ray single-crystal diffraction, X-ray powder diffraction, and IR spectroscopy. Complexes 1 and 2 crystallize in the same triclinic system of a P-1 space group, share the same composition, and 4·82 net topology, but have a different local coordination environment and symmetry for the LaIII ions, thus they form a pair of supramolecular isomers. Complex 3 contains two kinds of crystallographically independent LaIII ions and bis-chelating SO4 2– anions, to generate a 2D grid structure of (4, 4) topology. All three complexes display layered crystal packing in the crystal lattice. The thermogravimetric analyses indicate that the solvated and coordinated water molecules in all complexes can be removed upon heating, and the frameworks decompose above 400°C.