Homoleptic uranium and lanthanide phosphinodiboranates

Area of Science:

• Organometallic Chemistry
• Inorganic Chemistry
• Lanthanide and Actinide Chemistry

Background:

• Borohydride complexes are versatile ligands in coordination chemistry.
• Homoleptic f-element complexes offer unique electronic and magnetic properties.
• The synthesis of novel f-element compounds expands the scope of organometallic chemistry.

Purpose of the Study:

• To report a new class of homoleptic f-element borohydride complexes.
• To characterize the structure and solution behavior of these novel compounds.
• To explore the coordination chemistry of uranium, neodymium, and erbium with phosphinodiboranate ligands.

Main Methods:

• Reaction of f-element triiodides (UI3, NdI3, ErI3) with potassium phosphinodiboranate (K(H3BPtBu2BH3)).
• Synthesis was carried out in diethyl ether (Et2O).
• Characterization involved solid-state and solution studies.

Main Results:

• Successfully synthesized M2(H3BPtBu2BH3)6 complexes, where M = U, Nd, and Er.
• All three complexes exhibit dimer formation in the solid state.
• In solution, these complexes exist as an equilibrium mixture of monomers and dimers.

Conclusions:

• A new class of homoleptic f-element borohydride complexes, phosphinodiboranates, has been discovered.
• The coordination behavior of these f-element complexes shows a propensity for dimerization in the solid state.
• Solution studies reveal dynamic monomer-dimer equilibria, highlighting the ligand's flexibility.