The first cyclopentadienyl complex of uranyl

The U(IV) linear pentacyano metallocene [U(C5Me5)(2)(CN)(5)] [NEt4](3) reacted with 2 molar equivalents of pyridine N-oxide in THF or acetonitrile to give the U( VI) complex [UO2(C5Me5)(CN)(3)][NEt4](2), the first uranyl species containing the cyclopentadienyl ligand; the crystal structure revealed that the steric effects of the (C5Me5) ligand force the {UO2}(2+) ion to deviate from linearity.