Lutetium Catalysts

Lutetium is a chemical element with an atomic number of 71, symbol Lu. And it is the last element in the lanthanide. Lutetium is a silver-white metal, which is stable in dry air but susceptible to corrosion in humid air. The compounds of Lutetium always contain an element of oxidation state +3. Most aqueous solutions of the salt are colorless and form a white crystalline solid upon drying, except for the iodide. Lutetium metal is not only slightly unstable in air, but also burned at 150℃ easily to form oxidation under standard temperature and pressure. Due to its rare natural reserves, low toxicity and expensive price, lutetium is mainly used for research work and has few other uses.

Applications:

As mentioned above, due to difficulties in the production and high prices, lutetium has few commercial uses. However, some lutetium can be used as a catalyst in refinery petroleum cracking, alkylation, hydrogenation and polymerization applications because it is very stable. There are some specific examples as follows:

• Alkylation reaction: The use of activated Lu₂O₃ as a catalyst for the synthesis of di(2-ethylhexyl)phthalate (DOP) has a good catalytic effect. In addition, due to the solid-liquid phase catalysis, the reaction also has the advantages of easy separation and recovery of the catalyst, activation and regeneration, and low corrosivity.
• Hydrogenation reaction: After activation, the trialkyl rare earth compound [Lu(CH₂SiMe₃)₃(THF)₂] is used as a catalyst to catalyze the reaction of a benzyloxy complex with phenylsilicohydrogen (PhSiH₃) at room temperature to synthesize a heteroquinone mononuclear hydride L₄ZnH.
• Polymerization reaction: A lutetium porphyrin complex is prepared to catalyze the copolymerization of carbon dioxide and propylene oxide to form propylene carbonate. The specific reaction formula is shown in Figure 1(TPP=Tetraphenylporphyrin,TBAB=Tetrabutylammonium bromide).

Figure 1. The Reaction schematic of carbon dioxide and propylene oxide.

References

1. Meija, Juris, et al. (2016). 'Atomic weights of the elements 2013 (IUPAC Technical Report)'. Pure and Applied Chemistry. 88 (3), 265-91.
2. Ghosh A, Ramidi P, Pulla S, et al. (2010). 'Cycloaddition of CO2 to Epoxides Using a Highly Active Co(III) Complex of Tetraamidomacrocyclic Ligand'. Catal Lett.137, 1-7.
3. Wang W Z, Wu Y, Duan Y S, et al. (2013). 'An Efficient Catalyst System at Mild Reaction Conditions Containing Rare Earth Metal Complexes'. J Chin Chem Soc-taip. 60(12), 1463-1466.