[(C5Me5)2U][(mu-Ph)2BPh2] as a four electron reductant.

Examination of the reactivity of [(C5Me5)2U][(mu-Ph)2BPh2] as a "blank" for comparison with the four- and eight-electron reductive chemistry of the sterically crowded (C5Me5)3U and [(C5Me5)2U]2(C6H6) complexes revealed that the tetraphenylborate complex surprisingly functions as a four-electron reductant by combining [BPh4]1- and U(III) reduction; all three complexes cleave the N=N bond in PhN=NPh to form the bis(organoimido) U(VI) complex, (C5Me5)2U(NPh)2, and they also reduce PhC[triple bond]CPh to form (C5Me5)2U(C4Ph4).