A Lanthanum-Filled Carbon–Boron Clathrate
We report a carbon-boron clathrate with composition 2 La@B6C6 (LaB3C3). Like recently reported SrB3C3, single-crystal X-ray diffraction and computational modelling indicate that the isostructural La member crystallizes in the cubic bipartite sodalite structure (Type-VII clathrate) with La atoms encapsulated within truncated octahedral cages composed of alternating carbon and boron atoms. The covalent nature of the B−C bonding results in a hard, incompressible framework, and owing to the balanced electron count, La3+[B3C3]3− exhibits markedly improved pressure stability and is a semiconductor with an indirect band gap predicted near 1.3 eV. A variety of different guest atoms may potentially be substituted within Type-VII clathrate cages, presenting opportunities for a large family of boron-stabilized, carbon-based clathrates with ranging physical properties.
Angewandte Chemie - International Edition
Strobel, T., Zhu, L., Guńka, P., Borstad, G., & Guerette, M. (2021). A Lanthanum-Filled Carbon–Boron Clathrate. Angewandte Chemie - International Edition, 60 (6), 2877-2881. https://doi.org/10.1002/anie.202012821