_tcm18-11401.gif )
The international journal for inorganic, organometallic and bioinorganic chemistry
Subscribers
Non-subscribers
- Purchase article PDF [£30 + taxes]
- Purchase article PDF member offer [£5 + taxes]
Free access
Paper
Dalton Trans., 2009, 10474 - 10480, DOI: 10.1039/b913117e
Butterfly and rhombus structures for binuclear cobalt carbonyl sulfur and phosphinidene complexes of the type Co2(CO)6E2 (E = S, PX)
Guoliang Li, Qian-Shu Li, Ioan Silaghi-Dumitrescu, R. Bruce King and Henry F. Schaefer III
Theoretical studies on Co2(CO)6(PX)2 derivatives (X = H, Cl, OH, OMe, NH2, NMe2) predict the lowest energy structures to be butterfly structures containing five two-electron two-center bonds in the central Co2P2 unit. Among these butterfly structures the energy increases as the unique bond forming the
body
of the butterfly changes from Co–Co to Co–P and then P–P. Higher energy rhombus structures are also found for Co2(CO)6(PX)2 with only Co–P bonds in the Co2P2 framework without any Co–Co or P–P bonds. In addition, for Co2(CO)6(POR)2 (R = H, Me) still higher energy diphosphine structures are also found containing only three rather than four Co–P bonds, one P–P bond, and no Co
Co bond. For the isoelectronic Co2(CO)6S2 a rhombus structure is competitive in energy with the butterfly structures with five structures lying within 
4 kcal/mol thereby predicting a fluxional system. A tetrahedrane structure was not found for Co2(CO)6S2 in contrast to the tetrahedrane structure known experimentally for the related Fe2(CO)6S2 with one less electron per metal atom.
RSS feed