Premium
Trapping of a Highly Bent and Reduced Form of 2‐Phosphaethynolate in a Mixed‐Valence Diuranium–Triamidoamine Complex
Author(s) -
Magnall Rosie,
Balázs Gábor,
Lu Erli,
Tuna Floriana,
Wooles Ashley J.,
Scheer Manfred,
Liddle Stephen T.
Publication year - 2019
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201904676
Subject(s) - valence (chemistry) , cryptand , chemistry , bent molecular geometry , uranium , carbene , crystallography , ligand (biochemistry) , ion , computational chemistry , stereochemistry , materials science , organic chemistry , catalysis , biochemistry , receptor , metallurgy
The chemistry of 2‐phosphaethynolate is burgeoning, but there remains much to learn about this ligand, for example its reduction chemistry is scarce as this promotes P‐C‐O fragmentations or couplings. Here, we report that reduction of [U(Tren TIPS )(OCP)] (Tren TIPS =N(CH 2 CH 2 NSiPr i 3 ) 3 ) with KC 8 /2,2,2‐cryptand gives [{U(Tren TIPS )} 2 {μ‐η 2 (OP):η 2 (CP)‐OCP}][K(2,2,2‐cryptand)]. The coordination mode of this trapped 2‐phosphaethynolate is unique, and derives from an unprecedented highly reduced and highly bent form of this ligand with the most acute P‐C‐O angle in any complex to date (P‐C‐O ∡ ≈127°). The characterisation data support a mixed‐valence diuranium(III/IV) formulation, where backbonding from uranium gives a highly reduced form of the P‐C‐O unit that is perhaps best described as a uranium‐stabilised OCP 2−. radical dianion. Quantum chemical calculations reveal that this gives unprecedented carbene character to the P‐C‐O unit, which engages in a weak donor–acceptor interaction with one of the uranium ions.