Complexation of the uranyl ion (UO2)2+ with a tetraphenylimidodiphosphinate ligand: the first trinuclear uranyl complex comprising a double ?2-oxo (UO2) bridge

Reaction of K[(OPPh2)2N] with UO2(NO2)2 6H2O resulted in the formation of compound [UO2[(OPPh2)2N]2]3 (1). Single-crystal diffraction analysis of 1 reveals an elaborated and unique trinuclear uranyl compound, where the central UO2 moiety exhibits Lewis basic properties through an equatorial U?OUO?U bridging towards two outer uranyl units comprised in a six-membered ring array. The central and outer UO2 groups are also bridged by means of four eight-membered rings containing the ancillary ligand. The overall morphology of this compound may be regarded as a linear U3O2 core engaging two different types of environments for the uranium atoms.