Hydrothermal synthesis, structure, and properties of two new nanosized Ln₂₆ (Ln = Ho, Er) clusters

Abstract

Two new compounds, [Ho₂₆(IN)₂₈(CH₃COO)₄(CO₃)₁₀(OH)₂₆(H₂O)₁₈] · 20H₂O (1) (HIN = isonicotinic acid) and [Er₂₆(IN)₂₉(CH₃COO)₃(CO₃)₁₀(OH)₂₆(H₂O)₁₉] · 26H₂O (2), employing the building unit of CO₃@Ln₂₆ have been synthesized hydrothermally. Compound 1 crystallizes in the triclinic space group with a = 21.043(4) Å, b = 21.128(5) Å, c = 35.140(8) Å, α = 85.838(3)°, β = 74.909(3)°, γ = 85.414(3)°, V = 15,014(6) ų, Z = 2; 2 crystallizes in triclinic with a = 20.9968(15) Å, b = 21.1260(15) Å, c = 35.125(3) Å, α = 85.9530(10)°, β = 74.7590(10)°, γ = 85.5020(10)°, V = 14,966.3(18) ų, Z = 2. In the structures of both compounds, the isonicotinate (IN) is the main ligand while CH₃COO⁻ functions as the second ligand to stabilize the Ln₂₆ cluster; plays a very important role in the formation of the spherical Ln₂₆ cluster. The two compounds are isostructural and have been characterized by single-crystal X-ray diffraction, IR absorption spectroscopy, thermogravimetric analysis, ultraviolet excitation, and emission spectrum.

Keywords:

• Nanosized Ln–O cluster
• Hydrothermal synthesis
• Crystal structure

Acknowledgments

We thank the National Natural Science Foundation of China (20971068) for financial support.