Isolation of a Uranium(III)‐Carbon Multiple Bond Complex

Abstract

Low‐valent uranium‐element multiple bond complexes remain scarce, though there is burgeoning interest regarding to their bonding and reactivity. Herein, isolation of a uranium(III)‐carbon double bond complex [(Cp*)2U(CDP)](BPh4) (1) comprising a tridentate carbodiphosphorane (CDP) was reported for the first time. Oxidation of 1 afforded the corresponding U(IV) complex [(Cp*)2U(CDP)](BPh4)2 (2). The distance between U and C in 2 is 2.481 Å, indicating the existence of a typical U=C double bond, which is further confirmed by quantum chemical calculations. Bonding analysis suggested that the CDP also serves as both σ‐ and π‐donor in complex 1, though a longer U−C bond (2.666(3) Å) is observed. It implies that 1 is the first isolable mononuclear uranium(III) carbene complex. Moreover, these results suggest that CDPs are promising ligands to establish other low‐valent f‐block metal‐carbon multiple bond complexes.

From a mercury(ii) bis(yldiide) complex to actinide yldiides

“…Actinide-carbon multiple bonding has attracted attention in the past decade due to efforts to better understand actinide-ligand bonding and differences in coordination chemistry and reactivity between actinides and the rest of the periodic table. 1 Actinide carbene and carbene-like complexes have been reported with different ligand systems including widely used singlet carbenes [2][3][4][5][6][7][8][9][10][11][12][13] carbodiphospho ranes, [14][15][16][17] as well as highly nucleophilic methandiides (e.g. in A and B, Fig.…”

Distinguishing the Geometric and Electronic Structures of Actinide Carbides AnxC8 (An = Th, U; x = 2, 3) through Exchange Interactions

“…As is known, diverse actinide carbide ions have been observed with a wide range of stoichiometries. Besides the existence of UC, U 2 C 3 , and UC 2 in the condensed phase, diactinide carbides and polymeric carbon species have been produced in the gas phase. − This is because carbon has the capacity to have many oxidation states and coordination numbers, enabling it to bond with actinide ions in various forms. , Various aspects of the possible molecular structures of such complex carbides have recently been studied. ,, As such, the monoactinide polyatomic carbides have been predicted to adopt fan-shaped An-C n structures for the number of carbons within the range of 3 to 7 on the basis of the analogy between the C n radical and O atom − and a cyclic polycarbon structure in the case of the carbon number equal to 12 . For diactinide carbides, less is known about the molecular structure.…”

Structure of Uranium(V) Methyl and Uranium(IV) Ylide Complexes

“…Actinide–ligand multiple bonds can elucidate the role of the valence orbitals in the structure, bonding, and reactivity of the actinides . While first synthesized more than 40 years ago, few actinide–carbon multiple bonds have been reported, − and most involve the tetravalent oxidation state. All actinide–carbenoid complexes have an An–C bond that is stabilized by a heteroatom, − typically phosphorus, yielding phosphorano-stabilized carbenes or methandiides. , Only recently has the Hayton group used an allenylidene ligand to produce short An–C multiple bonds, but the major resonance form was primarily of An–C single-bond character .…”