Investigation of the Electronic Structure of Aryl-Bridged Dinuclear U(III) and U(IV) Compounds

A family
of dinuclear bis­(Tp*) (Tp* = hydrotris­(3,5-dimethylpyrazolyl)­borate)
uranium compounds with conjugated organic linkers was synthesized
to explore possible electronic communication between uranium ions.
Trivalent diuranium phenyl alkynyl compounds, Tp*2UCC­(1,3-C6H4)­CCUTp*2 (2-meta) or Tp*2UCC­(1,4-C6H4)­CCUTp*2 (2-para), and tetravalent diuranium
phenylimido compounds, Tp*2U­(N-1,3-C6H4–N)­UTp*2 (3-meta)
and Tp*2U­(N-1,4-C6H4–N)­UTp*2 (3-para), were generated from
trivalent Tp*2UCH2Ph. All compounds were fully
characterized both spectroscopically and structurally. The electronic
structures of all derivatives were interrogated using magnetic measurements,
electrochemistry, and were the subject of computational analyses.
All of these data combined established that little electronic communication
exists between the uranium centers in these trivalent and tetravalent
diuranium molecules.