Influence of the Lewis Base Ph3PO on the Reactivity of the Uranium Phosphinidene (η5-C5Me5)2U(═P-2,4,6-iPr3C6H2)(OPPh3)

Abstract

This paper describes the synthesis, structure, and reactivity of (η5-C5Me5)2U(═P-2,4,6-iPr3C6H2)(OPPh3) (2). Compound 2 can be accessed by a salt metathesis reaction of the uranium methyl chloride metallocene (η5-C5Me5)2U(Cl)Me (1) with 2,4,6-iPr3C6H2PHK in toluene in the presence of Ph3PO at ambient temperature. Furthermore, it reacts as a masked synthon for the divalent uranium fragment (η5-C5Me5)2U by elimination of the phosphinidene fragment (2,4,6-iPr3C6H2P:) on exposure to small organic molecules such as Ph2S2, Ph2Se2, bipy, ketazines, carbodiimides, diazenes, and organic azides. Nevertheless, it also forms carbodithioates, imido, diiminatos, and metallaaziridines when it is treated with isothiocyanate, nitriles, and isonitriles, respectively. In contrast, after addition of Me3SiN3 the uranium azido species (η5-C5Me5)2U[N(SiMe3)P(2-NHCMe2-4,6-iPr2C6H2)N(SiMe3)](N3) (13) is isolated in good yield.