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Probing a variation of the inverse-trans-influence in americium and lanthanide tribromide tris(tricyclohexylphosphine oxide) complexes† † Electronic supplementary information (ESI) available: Photographs of compounds, NMR spectra, electronic absorption spectra, additional theoretical calculation. CCDC 1959746–1959750. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c9sc05268b

ABSTRACT: The synthesis, characterization, and theoretical analysis of meridional americium tribromide tris(tricyclohexylphosphine oxide), mer-AmBr3(OPcy3)3, has been achieved and is compared with its early lanthanide (La to Nd) analogs. The data show that homo trans ligands display significantly shorter bonds than the cis or hetero trans ligands. This is particularly pronounced in the americium compound. DFT along with multiconfigurational CASSCF calculations show that the contraction of the bonds relates qualitatively with overall covalency, i.e. americium shows the most covalent interactions compared to lanthanides. However, the involvement of the 5p and 6p shells in bonding follows a different order, namely cerium > neodymium ∼ americium. This study provides further insight into the mechanisms by which ITI operates in low-valent f-block complexes. Structural, spectroscopic and theoretical analyses of mer-MBr3(OPcy3)3 (M = Am, Nd, Pr, Ce, La) reveal significant amounts of metal based p-orbital contribution.

SUBMITTER: Windorff C

PROVIDER: S-EPMC8157511 | biostudies-literature |

REPOSITORIES: biostudies-literature

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