Talk:Cerocene

Cerocene
https://en.wikipedia.org/wiki/Cerocene

There is a WRONG COMPOUND described and depicted on this page!

Cerocene should be Ce(C_8H_8)_2, just as Uranocene is U(C_8H_8)_2. These are classic compounds synthesized more than 30 or 40 years ago. It's TWO cyclo-OCTATETRAENE rings, not three cyclopendienyl ones!

Reference Uranocene: Streitwieser and Müller-Westerhoff, Bis(cyclooctatetraenyl)uranium (uranocene). A new class of sandwich complexes that utilize atomic f orbitals, J. Am. Chem. Soc., 90, 7364 (1968).

Reference Cerocene: A. Greco, S. Cesca, G. Bertolini, J. Organomet. Chem. 113 (1976) 321 New \pi-cyclooctatetraenyl and pi-cyclopentadienyl complexes of cerium, J. Org. Chem., 113, 321--330 (1976). I think you misinterpreted the paper of Greco and mixed up the compounds! The first in the title is cerocene, not the second!

Cf. e.g., your Ref. 5 (Chem. Soc. Rev., 2017, 46, 6697--6709) says on page 6701, bottom, left side: "... the other known formally tetravalent cerium organometallic complex Ce(C8 H 8 )2 (‘‘cerocene’’). "

Check also section 6 of your reference 5, which is entirely on the unusual electronic structure of cerocene.

Many papers in literature mention "cerocene", e.g. (I just paste a few references to convince you ..., check the titles and the chemical formulas!)

A. Streitwieser, S. A. Kinsley, J. T. Rigsbee, I. L. Fragala, E. Ciliberto, Photoelectron spectra and bonding in cerocene, bis-($\pi$-[8]annulene) cerium(IV), \textit{J. Am. Chem. Soc.}, \textbf{107}, 7786--7788 (1985).

\bibitem{dolg++:95} M.~Dolg, P.~Fulde, H.~Stoll, H.~Preuss, A.~Chang, R.~M. Pitzer, Formally tetravalent cerium and thorium compounds: A configuration interaction study of cerocene Ce(C$_ 8$H$_8$)$_2$ and thorocene Th(C$_8$H$_8$)$_2$ using energy-adjusted quasirelativistic ab initio pseudopotentials, \textit{{C}hem. {P}hys.}, \textbf{195}, 71--82 (1995). \bibitem{edelstein++:96} N.~Edelstein, P.~G. Allen, J.~J. Bucher, D.~K. Shuh, C.~D. Sofield, N.~Kaltsoy annis, G.~H. Maunder, M.~R. Russo, A.~Sella, The oxidation state of Ce in the sandwich molecule cerocene, \textit{{J}. {A}m. {C}hem. {S}oc.}, \textbf{118}, 13115--13116 (1996). \bibitem{kerridge++:09} A.~Kerridge, R.~Coates, N.~Kaltsoyannis, Is cerocene really a Ce(III) compound ? All-electron spin-orbit coupled CASPT2 calculations on M($\eta^ 8$-C$_8$H$_8$)$_2$ (M = Th, Pa, Ce), \textit{{J}. {P}hys. {C}hem. {A}}, \textbf{113}, 2896--2905 (2009). \bibitem{moossen+dolg:14} O. Moo{\ss}en, M. Dolg, Two interpretations of the cerocene electronic ground state. \textit{Chem. Phys. Lett.}, \textbf{594}, 47-50 (2014).

(You can trust me, I was involved in the research on cerocene since 30 years) Best wishes, Michael Dolg (Prof. Dr.) Beijing Normal University and University of Cologne

E-Mail: m.dolg@uni-koeln.de 2A00:A200:0:E00:0:0:0:1F (talk) 02:38, 27 May 2024 (UTC)