_P.-Powell-auth.-Principles-of-Organometallic-Chemistry-Springer-Netherlands-1988

Cyclopentadienylmetal carbonyls
[cpFe(C0)2 (C2H4 ~+
Ag +) C 2H 4
~ t[cpFe(COl2] 2
CpFeH(C0)2
Labile
CpFe-Hg-FeCp
(C0)2 (C0)2
METAL- METAL BONDS
CpFe(C0) 2 CH 3
l PPh3
CpF e(CO)(COCH3 )( PPh 3 )
migrotory insertion
-co j hv
~ 3 -ollyl
Fig. 9.11 Summary of reactions of the anion [CpFe(CO)X.
that there is little electron density directly between the iron atoms in these structures,
but rather a zone of electron density around the Fe 2 C 2 system. This suggests
that electron sharing between the two CpFe(C0) 2 units may occur largely in
delocalized multicentre bonds rather than by direct metal-metal interaction.
Direct metal-metal bonding, unsupported by carbonyl bridges, occurs however
in the osmium analogue [Cp0s(C0) 2 L. It is also found in [CpM(C0) 3 L (M = Cr,
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