Ionothermal Synthesis of Am4B22O42Cl12: A Chiral Cubic Americium Borate Cluster

Ionic liquids were used as low temperature solvents for the synthesis of new lanthanide and transuranic-element (TRU) borate cluster structures. Ionothermal synthesis with the ionic liquid [BMIm]Cl (1-butyl-3-methylimidazolium chloride) yielded the La, Nd, and Am containing phases La4B22O42Cl12, Nd4B22O42Cl12, and Am4B22O42Cl12. The structures of the La, Nd, and Am borate clusters were determined by single crystal X-ray diffraction (SCXRD) and found to be cubic, in the chiral space group I23. Solid state NMR and Raman spectra confirm the structure descriptions. This represents the first ionothermal synthesis of an americium containing cluster compound, and the study of such low-temperature methods benefit work on TRU materials.