Revisiting the Chemistry of the Actinocenes [(η8‑C8H8)2An] (An = U, Th) with Neutral Lewis Bases. Access to the Bent Sandwich Complexes [(η8‑C8H8)2An(L)] with Thorium (L = py, 4,4′-bipy, tBuNC, R4phen)

In stark contrast to uranocene, (Cot)2Th reacts with neutral mono- or bidentate Lewis bases to give the bent sandwich complexes (Cot)2Th­(L) (L = py, 4,4′-bipy, tBuNC, phen, Me4phen). DFT calculations in the gas phase show that, for both U and Th, formation of the bent compound (Cot)2An­(L) should be facile, the linear and bent forms being close in energy.