Jori, NadirBarluzzi, LucianoDouair, IskanderMaron, LaurentFadaei-Tirani, FarzanehZivkovic, IvicaMazzanti, Marinella2021-08-142021-08-142021-08-142021-07-2810.1021/jacs.1c05389https://infoscience.epfl.ch/handle/20.500.14299/180595WOS:000679913600050Multimetallic cooperativity is believed to play a key role in the cleavage of dinitrogen to nitrides (N3-), but the mechanism remains ambiguous due to the lack of isolated intermediates. Herein, we report the reduction of the complex [K-2{[U-V(OSi((OBu)-Bu-t)(3))(3)](2)(mu-O)(mu-eta 2(:)eta(2)-N-2)}], B, with KC8, yielding the tetranuclear tetranitride cluster [K-6{(OSi((OBu)-Bu-t)(3))(2)UIV}(3){(OSi((OBu)-Bu-t)(3))(2)UVI}(mu(4)-N)(3)(mu(3)-N)(mu(3)-O)(2)], 1, a novel example of N2 cleavage to nitride by a diuranium complex. The structure of complex 1 is remarkable, as it contains a unique uranium center bound by four nitrides and provides the second example of a trans-N=U-VI=N core analogue of UO22+. Experimental and computational studies indicate that the formation of the U(IV)/U(VI) tetrauranium cluster occurs via successive one-electron transfers from potassium to the bound N-2(4-) ligand in complex B, resulting in N2 cleavage and the formation of the putative diuranium(V) bis-nitride [K-4{[UV(OSi-((OBu)-Bu-t)(3))(3)](2)(mu-O)(mu-N)(2)}], X. Additionally, cooperative potassium binding to the U-bound N24- ligand facilitates dinitrogen cleavage during electron transfer. The nucleophilic nitrides in both complexes are easily functionalized by protons to yield ammonia in 93-97% yield and with excess (CO)-C-13 to yield (KCN)-C-13 and (KNCO)-C-13. The structures of two tetranuclear U(IV)/U(V) bis- and mononitride clusters isolated from the reaction with CO demonstrate that the nitride moieties are replaced by oxides without disrupting the tetranuclear structure, but ultimately leading to valence redistribution.Chemistry, MultidisciplinaryChemistrynitrogen atom-transfermagnetic communicationnitride complexesend-oncleavageactivationazidefunctionalizationchemistrybondstext::journal::journal article::research article