The structure and fluxionality of [Fe-3(CO)(10)(dppe)]; a merry-go-round with no sense of direction

Citation
H. Adams et al., The structure and fluxionality of [Fe-3(CO)(10)(dppe)]; a merry-go-round with no sense of direction, J ORGMET CH, 607(1-2), 2000, pp. 175-181
Citations number
13
Categorie Soggetti
Organic Chemistry/Polymer Science
Journal title
JOURNAL OF ORGANOMETALLIC CHEMISTRY
ISSN journal
0022328X → ACNP
Volume
607
Issue
1-2
Year of publication
2000
Pages
175 - 181
Database
ISI
SICI code
0022-328X(20000811)607:1-2<175:TSAFO[>2.0.ZU;2-Q
Abstract
The crystal structure of [Fe-3(CO)(10)(dppe)] has been determined. The Ph2P CH2CH2PPh2 ligand bridges the Fe(mu-CO)(2)Fe edge and is markedly non-plana r. The non-planarity inverts with Delta G(211)(double dagger) = 48.4 +/- 0. 5 kJ mol(-1). The carbonyls on the bridged iron atoms exchange with the axi al ones by the merry-go-round mechanism with Delta G(195)(double dagger) = 43.4 +/- 0.5 kJ mol(-1). Despite the non-planar dppe ligand producing a chi ral molecule, the merry-go-round exchange goes with equal rate in both dire ctions. This is the first example of a six-toothed failed ratchet. (C) 2000 Elsevier Science S.A. All rights reserved.