A Very Short Uranium(IV)–Rhodium(I) Bond with Net Double‐Dative Bonding Character. (27th April 2018) - Lu, Erli
Abstract: Reaction of [U{C(SiMe3 )(PPh2 )}(BIPM)(μ‐Cl)Li(TMEDA)(μ‐TMEDA)0.5 ]2 (BIPM=C(PPh2 NSiMe3 )2 ; TMEDA=Me2 NCH2 CH2 NMe2 ) with [Rh(μ‐Cl)(COD)]2 (COD=cyclooctadiene) affords the heterotrimetallic U IV −Rh I 2 complex [U(Cl)2 {C(PPh2 NSiMe3 )(PPh[C6 H4 ]NSiMe3 )}{Rh(COD)}{Rh(CH(SiMe3 )(PPh2 )}]. This complex has a very short uranium–rhodium distance, the shortest uranium–rhodium bond on record and the shortest actinide–transition metal bond in terms of formal shortness ratio. Quantum‐chemical calculations reveal a remarkable Rh I → → U IV net double dative bond interaction, involving Rh I 4d z 2 ‐ and 4dxy/xz ‐type donation into vacant U IV 5f orbitals, resulting in a Wiberg/Nalewajski–Mrozek U−Rh bond order of 1.30/1.44, respectively. Despite being, formally, purely dative, the uranium–rhodium bonding interaction is the most substantial actinide–metal multiple bond yet prepared under conventional experimental conditions, as confirmed by structural, magnetic, and computational analyses. Abstract : In der Kürze liegt die Würze : Die kürzeste bekannte U‐Rh‐Bindung sowie die kürzeste Actinoid‐Übergangsmetall‐Bindung in Bezug auf das formale Kürzeverhältnis wurden gefunden. Überraschenderweise decken quantenmechanische Rechnungen eine dative Netto‐Doppelbindung, Rh I → → U IV, mit einer Nalewajski‐Mrozek‐Bindungsordnung von 1.44 auf.