Actinide-Pnictide (An-Pn) Bonds Spanning Non-Metal, Metalloid, and Metal Combinations (An=U, Th; Pn=P, As, Sb, Bi).

The synthesis and characterisation is presented of the compounds [An(Tren ){Pn(SiMe ) }] and [An(Tren ){Pn(SiMe ) }] [Tren =N(CH CH NSiMe Bu ) , An=U, Pn=P, As, Sb, Bi; An=Th, Pn=P, As; Tren =N(CH CH NSiPr ) , An=U, Pn=P, As, Sb; An=Th, Pn=P, As, Sb]. The U-Sb and Th-Sb moieties are unprecedented examples of any kind of An-Sb molecular bond, and the U-Bi bond is the first two-centre-two-electron (2c-2e) one. The Th-Bi combination was too unstable to isolate, underscoring the fragility of these linkages.

Crystalline Diuranium Phosphinidiide and μ-Phosphido Complexes with Symmetric and Asymmetric UPU Cores.

Reaction of [U(Tren )(PH )] (1, Tren =N(CH CH NSiPr ) ) with C H CH K and [U(Tren )(THF)][BPh ] (2) afforded a rare diuranium parent phosphinidiide complex [{U(Tren )} (μ-PH)] (3). Treatment of 3 with C H CH K and two equivalents of benzo-15-crown-5 ether (B15C5) gave the diuranium μ-phosphido complex [{U(Tren )} (μ-P)][K(B15C5) ] (4). Alternatively, reaction of [U(Tren )(PH)][Na(12C4) ] (5, 12C4=12-crown-4 ether) with [U{N(CH CH NSiMe Bu ) CH CH NSi(Me)(CH )(Bu )}] (6) produced the diuranium μ-phosphido complex [{U(Tren )}(μ-P){U(Tren )}][Na(12C4) ] [7, Tren =N(CH CH NSiMe Bu ) ].

Terminal Parent Phosphanide and Phosphinidene Complexes of Zirconium(IV).

The reaction of [Zr(Tren )(Cl)] [Zr1; Tren =N(CH CH NSiMe Bu ) ] with NaPH gave the terminal parent phosphanide complex [Zr(Tren )(PH )] [Zr2; Zr-P=2.690(2) Å]. Treatment of Zr2 with one equivalent of KCH C H and two equivalents of benzo-15-crown-5 ether (B15C5) afforded an unprecedented example (outside of matrix isolation) of a structurally authenticated transition-metal terminal parent phosphinidene complex [Zr(Tren )(PH)][K(B15C5) ] [Zr3; Zr=P=2.