The first suberato-bridged lanthanide coordination polymer: synthesis, crystal structure and properties of La₂(H₂O)₂L₃ (H₂L=HOOC(CH₂)₆COOH)

Abstract

Reaction of suberic acid (H₂L = HOOC(CH₂)₆COOH), LaCl₃ and NaOH at 170°C yielded La₂(H₂O)₂L₃. The complex is triclinic, space group P , with a = 8.246(1), b = 13.463(2), c = 14.073(2) Å, α = 104.29(1)°, β = 105.07(1)°, γ = 93.61(1)°, Z = 2, V = 1448.4(3) ų, R ₁ = 0.0324 and wR ₂ = 0.0723 for 5319 observed reflections (I ≥ 2σ(I)) of 6597 unique reflections. The crystal structure features infinite lanthanum oxide chains of edge-sharing (LaO₉) mono-capped square antiprisms, in which La atoms are coordinated by nine oxygen atoms of six suberate anions and one water molecule at the cap with d(La–O) = 2.475–2.666 Å. The chains are bridged by the dicarboxylate anions to form a 3D, nonporous framework and interchain hydrogen bonding interactions between the capping water and carboxylate oxygen atoms contribute to the stabilization of the crystal structure. Thermogravimetric and IR properties are presented.

Keywords:

• Lanthanum(III)
• Suberato complex
• Coordination polymer
• Hydrothermal synthesis
• Crystal structure

Acknowledgements

The project was supported by the State Basic Research Project of China scheme (2003CCA00800), the Zhejiang Provincial Natural Science Foundation (Z203067) and the Ningbo Municipal Science Foundation (2003A62011, 2003A61014, 2003A62026).