On the Linear Geometry of Lanthanide Hydroxide (Ln—OH, Ln=La-Lu)

Abstract

Lanthanide hydroxides are key species in a variety of catalytic processes and in the preparation of corresponding oxides. This work explores the fundamental structure and bonding of the simplest lanthanide hydroxide, LnOH (Ln=La-Lu), using density functional theory calculations. Interestingly, the calculations predict that all structures of this series will be linear. Furthermore, these results indicate a valence electron configuration featuring an occupied sigma orbital and two occupied pi orbitals for all LnOH compounds, suggesting that the lanthanide-hydroxide bond is best characterized as a covalent triple bond.

A Density Functional Theory Investigation of the Reaction of Water with Ce2O-

“…17 While the effect of this ratio on the reactivity with water is still not fully understood, our analysis using a molecular orbital approach shows that the reaction of Ce 2 Oclusters is driven by delocalized 5d electrons. A similar feature has been observed in a recent study 69 in which we showed the significant role that lanthanide-based 5d orbitals play in the structure and bonding across the lanthanide hydroxide series. Studying cluster reactivity with varying ratios of lanthanides to oxides provides further understanding of the reactivity motifs of these clusters and insight for designing catalysts that can efficiently carry out efficient hydrogen gas production.…”

“…Several studies have shown that the orbitals involved in chemical processes on lanthanides and lanthanide-based clusters involve 6s and 5p orbitals, while the occupation number of 4f orbitals remains intact. 46,47,[69][70][71][72]76 While the cerium-based 6s orbitals have been previously determined to be the sites of electron detachments in various cerium and cerium suboxide clusters (including Ce 2 Oand Ce 2 O -2 ), we notice here that both σ and σ * orbitals retain all or most of their electron occupations as the reaction proceeds. This shows that σ and σ * electrons are not the source of metal facilitated reduction of water.…”

“…The approach used here follows from our previous experience working with such systems as well as studies reported by other groups. 46,47,51,[69][70][71][72][73][74][75] 3 Results…”

A Density Functional Theory Investigation of the Reaction of Water with Ce2O-

“…Several studies have shown that the orbitals involved in chemical processes on lanthanides and lanthanide-based clusters involve 6s and 5p orbitals, while the occupation number of 4f orbitals remains intact. [37][38][39][40][41][42][43] Several experimental and computational studies have been performed on cerium oxide clusters in order to better understand the electronic structure features that pave the way to a thorough understanding of their reactivity and catalytic activity. In addition, various experimental and theoretical studies have explored the reactivity of classes of cerium-based clusters with various gas-phase small molecules.…”