Chinese research team successfully synthesizes rare earth triple bond compounds

According to Science and Technology Daily, recently, our country's scientific research team has successfully realized the preparation of rare earth triple bond compounds, which have long been regarded as "scientific research forbidden areas", breaking the traditional cognition of the bonding ability of rare earth elements, and providing a new experimental basis and theoretical support for the development of rare earth chemical bonding theory. The relevant research results have recently been published in the journal Nature Chemistry.

It is understood that rare earth elements include scandium, yttrium and 15 lanthanides, and their electronic structures are extremely complex, special and diverse. The successful construction of stable rare earth triple bonds can not only promote the development of rare earth element valence bond theory, but also provide a new path for the design of new rare earth catalysts and the development of advanced functional materials. Recently, Chen Ning's research group of Soochow University and Li Jun's research group of Tsinghua University innovatively used the spatial limitation and protective effect of fullerene molecular cages to successfully prepare the first triple bond compound formed by the rare earth element cerium and carbon embedded in fullerenes by using improved arc discharge technology, realizing the stable construction of cerium-carbon triple bonds.

X-ray single-crystal diffraction analysis shows that the cerium-carbon bond length in this structure is highly consistent with the theoretical prediction of triple bond length. Through the combined characterization of visible-near-infrared absorption spectroscopy, electron paramagnetic resonance spectroscopy, and quantum chemistry, the team further confirmed that the compound has an electronic configuration with a closed shell. The characteristic vibrational peaks of cerium-carbon bonds observed in the infrared spectrum are consistent with the theoretical simulation results, providing direct evidence for the existence of rare earth triple bonds.