Theoretical Treatment of Redox Processes Involving Lanthanide(II) Compounds: Reactivity of Organosamarium(II) and Organothulium(II) Complexes with CO₂ and Pyridine

Abstract

An effective methodology to deal with the theoretical treatment on the redox chemistry of divalent organolanthanide complexes is reported and has been tested on two representative substrates, pyridine and CO(2), with two different metals (samarium and thulium). An influence of the ancillary ligands, namely, C(5)Me(5) (Cp*) or (2,3,4,5-tetramethylphospholyl) (Tmp), on the one- or two-electron oxidation processes is observed. The theoretical results are in excellent agreement with the experimental observations indicating the efficiency of the method.

Controlling selectivity in the reductive activation of CO2 by mixed sandwich uranium(iii) complexes

“…The methodology used to compute this oxidation step has been described previously for uranium and samarium complexes. 43,44 For both systems 1_Me and 1_tBu, two structural conformations of this key intermediate were optimized, depending on the orientation of the ligands (Figure 8 for R=Me). In the first confirmation (complex 2_R), the silyl groups of the COT ligands point towards the equatorial plane (where the CO 2 2moiety is lying) and the COT ligand of one uranium center faces the Cp* ligand of the other uranium center in the dimer.…”

Beyond Samarium Diiodide: Vistas in Reductive Chemistry Mediated by Lanthanides(II)

“…The future advances in this field may cover redox-active ligands, [118] photoinduced reductions, [119] enantioselective variants, [120] and theoretical studies using computational models. [121] Collectively, the exciting innovations in the reductive chemistry of lanthanides provide a fresh impetus in the quest to develop electron-transfer processes that proceed with useful efficiency and selectivity, mediated by new, tailor-made lanthanide reductants.…”

Insights into the Mechanism of Reaction of [(C5Me5)2SmII(thf)2] with CO2 and COS by DFT Studies

“…The methodology used for computing the oxidation step was reported by Castro et al [16] and involved uranium systems. It was extended by Labouille et al [27] and Iftner et al [28] to include divalent lanthanides. The reactant [(C 5 Me 5 ) 2 Sm II ] (1) and the mononuclear radical anionic species [(C 5 (2) were computed with the 4f-in-valence ECP for Sm to account for oxidation from OS + 2 to + 3.…”