Metalloradical Cations and Dications Based on Divinyldiphosphene and Divinyldiarsene Ligands.

Metalloradicals are key species in synthesis, catalysis, and bioinorganic chemistry. Herein, two iron radical cation complexes ( 3-E )GaCl 4 [( 3-E ) •+ = [{(IPr)C(Ph)E} 2 Fe(CO) 3 ] •+ , E = P or As; IPr = C{(NDipp)CH} 2 , Dipp = 2,6- i Pr 2 C 6 H 3 ] are reported as crystalline solids. Treatment of the divinyldipnictenes {(IPr)C(Ph)E} 2 ( 1-E ) with Fe 2 (CO) 9 affords [({(IPr)C(Ph)E} 2 )Fe(CO) 3 ] ( 2-E ), in which 1-E binds to the Fe atom in an allylic (η 3 -EEC vinyl ) fashion and functions as a 4e-donor ligand. 2-E undergo 1e-oxidation with GaCl 3 to yield ( 3-E )GaCl 4 . Spin-density analysis reveals that the unpaired electron in ( 3-E ) •+ is mainly located on the Fe (52-64%) and vinylic C (30-36%) atoms. Further 1e-oxidation of ( 3-E )GaCl 4 leads to an unprecedented η 3 -EEC vinyl to η 3 -EC vinyl C Ph coordination shuttling to form the dications ( 4-E )(GaCl 4 ) 2 .