Electronic Structure of Strained Silicon- and Sulfur-Bridged [1]Ferrocenophanes and an Analogous Dicarbon-Bridged [2]Ferrocenophane: An Investigation by Photoelectron Spectroscopy and Density-Function
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- 作者：Stephen Barlow ; Mark J. Drewitt ; Tessa Dijkstra ; Jennifer C. Green ; Dermot O'Hare ; Conrad Whittingham ; Hamish H. Wynn ; Derek P. Gates ; Ian Manners ; James M. Nelson ; and John K. Pudelski
- 刊名：Organometallics
- 出版年：1998
- 出版时间：May 11, 1998
- 年：1998
- 卷：17
- 期：10
- 页码：2113 - 2120
- 全文大小：144K
- 年卷期：v.17,no.10(May 11, 1998)
- ISSN：1520-6041
文摘
He I and He II photoelectron (PE) spectra of[Fe(
-C5H4)2SiMe2](1),[Fe(-C5H3Me)2SiMe2](2),[Fe(-C5H4)(-C5Me4)SiMe2](3),[Fe(-C5Me4)2SiMe2](4),[Fe(-C5H4)2C2H4](5), and [Fe(-C5H4)2S] (6) havebeen measured and assigned. The d bands of1-5 show less structurethan that of ferrocene, consistent with a loss of degeneracy of thee2 orbitals on bending.Compound 6, which has the largest inter-ring angle ofthe series, shows two separate dbands. The trend in the first ionization energy closely parallelsthe variation in oxidationpotential. Density functional calculations on 1,5, and 6 give geometries in goodagreementwith the structures found from X-ray diffraction. Ionizationenergies calculated were alsoin excellent agreement with experiment. Good agreement was alsofound between thecalculated d-d transitions and the position of the first spin-allowedband in the opticalspectra of 1 and 6. Estimates of strainenergy in bending ferrocene and octamethylferrocenewere obtained, and octamethylferrocene was shown to be significantlymore difficult to bend.Compounds 1 and 6 were both shown to have alow-lying empty orbital, partially located onthe ipso carbon, which is a possible site for nucleophilicattack in the polymerization processundergone by these compounds.
-C5H4)2SiMe2](1),[Fe(-C5H3Me)2SiMe2](2),[Fe(-C5H4)(-C5Me4)SiMe2](3),[Fe(-C5Me4)2SiMe2](4),[Fe(-C5H4)2C2H4](5), and [Fe(-C5H4)2S] (6) havebeen measured and assigned. The d bands of1-5 show less structurethan that of ferrocene, consistent with a loss of degeneracy of thee2 orbitals on bending.Compound 6, which has the largest inter-ring angle ofthe series, shows two separate dbands. The trend in the first ionization energy closely parallelsthe variation in oxidationpotential. Density functional calculations on 1,5, and 6 give geometries in goodagreementwith the structures found from X-ray diffraction. Ionizationenergies calculated were alsoin excellent agreement with experiment. Good agreement was alsofound between thecalculated d-d transitions and the position of the first spin-allowedband in the opticalspectra of 1 and 6. Estimates of strainenergy in bending ferrocene and octamethylferrocenewere obtained, and octamethylferrocene was shown to be significantlymore difficult to bend.Compounds 1 and 6 were both shown to have alow-lying empty orbital, partially located onthe ipso carbon, which is a possible site for nucleophilicattack in the polymerization processundergone by these compounds.