Multielectron Redox Chemistry of Ytterbium Complexes Reaching the +1 and Zero Formal Oxidation States.

Lanthanide redox reactivity remains limited to one-electron transfer reactions due to their inability to access a broad range of oxidation states. Here, we show that multielectron reductive chemistry is achieved for ytterbium by using the tripodal tris(siloxide)arene redox-active ligand, which can store two electrons in the arene anchor. Reduction of the Yb(III) complex of the tris(siloxide)arene tripodal ligand affords the Yb(II) analogue by metal-centered reduction.

Enantiospecific Synthesis of Planar Chiral Rhodium and Iridium Cyclopentadienyl Complexes: Enabling Streamlined and Computer-Guided Access to Highly Selective Catalysts for Asymmetric C-H Functionalizations.

Chiral cyclopentadienyl (Cp) metal complexes are frequently used in asymmetric catalysis by virtue of their high reactivity and selectivity. Planar-chiral-only rhodium and iridium cyclopentadienyl complexes are particularly promising due to unrestricted chemical space for Cp ligand design while retaining structural simplicity. However, they are currently still niche because of a lack of efficient synthetic strategies that avoid lengthy chiral auxiliary routes or chiral preparatory HPLC resolution of the complexes.

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.

Synthesis, structure and redox properties of single-atom bridged diuranium complexes supported by aryloxides.

Single-atom (group 15 and group 16 anions) bridged dimetallic complexes of low oxidation state uranium provide a convenient route to implement multielectron transfer and promote magnetic communication in uranium chemistry, but remain extremely rare. Here we report the synthesis, redox and magnetic properties of N, O, and S bridged diuranium complexes supported by bulky aryloxide ligands. The U(IV)/U(IV) nitride [Cs(THF)][(U(OAr))(μ-N)], 1 could be prepared and characterized but could not be reduced.

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).