The first example of the two-electron reduction of a phosphaalkyne - Synthesis and structural characterisation of the diuranium(IV) pentalene complex [(U{?⁵-C5Me5}{?⁸-C 8H4(SiiPr3-1,4)2}) 2(µ-?²:?¹-tBuCP)]

The facile two-electron reduction of the phosphaalkyne tBuC=P by the U III cyclopentadienyl-pentalene mixed-sandwich complex [U(?5-C5Me5){?8-C 8H4(SiiPr3)2}] is reported. A single-crystal X-ray structural analysis of the diuranium(IV) product [(U{?5-C5Me5}{?8-C 8H4(SiiPr3)2})2(µ- tBuCP)] shows that it contains a slightly unsymmetrical, bridging µ-?2:?1- ligated phosphaalkene dianion.