Weakly-coordinating anions stabilise the unprecedented monovalent and divalent η-benzene nickel cations [(η-C5H5)Ni(ν-C6H6)Ni(ν- C5H5)]2+ and [Ni(ν-C6H6)2]2+

1. Priego, J.L.
2. Doerrer, L.H.
3. Rees, L.H.
4. Green, M.L.H.