1. 1. Hoffmann, R.J.Chem.Phys. 1963, 39, 1397; Hoffmann, R.;Lipscomh, U.N.Ibid. 1962, 36, 2179. Atomic parameters: see ref./16/ and Albright, T.A.;Hofmann, P.; Hof f mann, R.J. Am. Chem. Soc.
2. 2. 1977, 99, 7546. A modified version of the Wolfsberg-Helmholz formula was used throughout: Ammeter, J.H.;B??rgi, H.-B.; Thibeault, 3.C.;Hoffmann, R.J.Am.Chem.Soc. 197B, 100, 3666.
3. Wolczanski, P.T.; Bercaw, J.E.Acc.Chem.Res. 1980, 13, 121. b) Erker, G.Ibid 1984, 17, 103, and references therein. The related carbonylation chemistry of analogous actinide systems will not be discussed here.
4. Fachinetti. G.; Fochi, G.; Floriani, C.J.Chem.Soc., Dalton Trans. 1977, 1946. b) Fachinetti.G.;Floriani, C.; Marchetti, F.; Merlino, S.J.Chem. Soc., Chem.Commun. 1976, 522.
5. Erker, G.; Rosenfeldt, F. J.Organometal.Chem. 1980, 188, C1. b) Erker, G.; Rasenfeldt, F.Anqew.Chem. 1978; 90, 640.