Dinitrogen Reduction and Functionalization by a Siloxide Supported Thulium-Potassium Complex for the Formation of Ammonia or Hydrazine Derivatives.

The dinitrogen (N) chemistry of lanthanides remains less developed compared to the d-block metals and lanthanide-promoted N functionalization chemistry in well-defined lanthanide complexes remains elusive. Here we report the synthesis and characterization (SQUID, EPR, DFT, X-Ray) of the siloxide supported heterobimetallic (Tm/K) complexes [{KTm(OSi(OBu))}(μ-η : η-N)] (1) and [K{Tm(OSi(OBu))}(μ-η : η-N)] (2). Complex 2 provides a rare example of a metal complex of the triply reduced N radical.

Iron promoted end-on dinitrogen-bridging in heterobimetallic complexes of uranium and lanthanides.

End-on binding of dinitrogen to low valent metal centres is common in transition metal chemistry but remains extremely rare in f-elements chemistry. In particular, heterobimetallic end-on N bridged complexes of lanthanides are unprecedented despite their potential relevance in catalytic reduction of dinitrogen. Here we report the synthesis and characterization of a series of N bridged heterobimetallic complexes of U(iii), Ln(iii) and Ln(ii) which were prepared by reacting the Fe dinitrogen complex [Fe(depe)(N)] (depe = 1,2-bis(diethylphosphino)-ethane), complex A with [M{N(SiMe)}] (M = U, Ce, Sm, Dy, Tm) and [Ln{N(SiMe)}], (Ln = Sm, Yb).

Multielectron Redox Chemistry of Uranium by Accessing the +II Oxidation State and Enabling Reduction to a U(I) Synthon.

The synthesis of molecular uranium complexes in oxidation states lower than +3 remains a challenge despite the interest for their multielectron transfer reactivity and electronic structures. Herein, we report the one- and two-electron reduction of a U(III) complex supported by an arene-tethered tris(siloxide) tripodal ligand leading to the mono-reduced complexes, [K(THF)U((OSi(OBu)Ar)-arene)(THF)] () and [K(2.2.