Binding and Redox Properties of Iron(II) Bonded to an Oxo Surface Modeled by Calix[4]arene
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- 作者：Vittorio Esposito ; Euro Solari ; Carlo Floriani ; Nazzareno Re ; Corrado Rizzoli ; and Angiola Chiesi-Villa
- 刊名：Inorganic Chemistry
- 出版年：2000
- 出版时间：June 12, 2000
- 年：2000
- 卷：39
- 期：12
- 页码：2604 - 2613
- 全文大小：247K
- 年卷期：v.39,no.12(June 12, 2000)
- ISSN：1520-510X
文摘
The syntheses of the parent compounds [{p-But-calix[4]-(O)2(OR)2}Fe-L] [R = Me, L = THF, 5; R = Bun,L = THF, 6; R = PhCH2, L = THF, 7; R = SiMe3, L = none, 8] have been performed by reacting the protonatedform of the dialkylcalix[4]arene with [Fe2Mes4] [Mes = 2,4,6-Me3C6H2]. All of them undergo one-electron oxidativefunctionalization. By use of different oxidizing agents, the following iron(III) derivatives have been obtained:[{p-But-calix[4]-(O)2(OR)2}Fe-X] [X = Cl, R = Me, 9; X = I, R = Me, 10] and [{p-But-calix[4]-(O)2(OR)2}2Fe2(
-X] [X = O, R = Me, 11; X = O, R = Bun, 12; X = S, R = Me, 13], 9 and 10 being particularlyappropriate for a further functionalization of the metal. The last three display typical antiferromagnetic behavior[J = -78.6 cm-1, 11; J = -64.1 cm-1, 13]. In the case of 7 and 8, the reaction with O2 led to the dealkylationof one of the alkoxo groups, with the formation of a dimeric iron(III) derivative {[-p-But-calix[4]-(O)3(OR)}2Fe2][R = PhCH2, 14; R = SiMe3, 15] [J = -9.8 cm-1]. The reaction of the parent compounds with ButNC anddiazoalkanes led to the formation of [Fe=C] functionalities supported by a calix[4]arene oxo surface. The followingcompounds have been isolated and characterized: {[p-But-calix[4]-(O)2(OR)2}Fe=CNBut] [R = SiMe3, 16,
CN = 2175 cm-1], {[p-But-calix[4]-(O)2(OR)2}Fe=CPh2] [R = Me, 17; R = PhCH2, 18; R = SiMe3, 19]. Thethree carbene complexes 17-19 display quite an unusual high-spin state, which is a consequence of the formationof a weak 
interaction between the metal and the carbene carbon, as confirmed by the extended Hückel calculations.The carbene functionality has been removed from the iron center in the reaction with O2 and HCl. The proposedstructures have been supported by X-ray analyses of complexes 8, 9, 12, 14, 16, 17, and 19.
-X] [X = O, R = Me, 11; X = O, R = Bun, 12; X = S, R = Me, 13], 9 and 10 being particularlyappropriate for a further functionalization of the metal. The last three display typical antiferromagnetic behavior[J = -78.6 cm-1, 11; J = -64.1 cm-1, 13]. In the case of 7 and 8, the reaction with O2 led to the dealkylationof one of the alkoxo groups, with the formation of a dimeric iron(III) derivative {[-p-But-calix[4]-(O)3(OR)}2Fe2][R = PhCH2, 14; R = SiMe3, 15] [J = -9.8 cm-1]. The reaction of the parent compounds with ButNC anddiazoalkanes led to the formation of [Fe=C] functionalities supported by a calix[4]arene oxo surface. The followingcompounds have been isolated and characterized: {[p-But-calix[4]-(O)2(OR)2}Fe=CNBut] [R = SiMe3, 16,CN = 2175 cm-1], {[p-But-calix[4]-(O)2(OR)2}Fe=CPh2] [R = Me, 17; R = PhCH2, 18; R = SiMe3, 19]. Thethree carbene complexes 17-19 display quite an unusual high-spin state, which is a consequence of the formationof a weak interaction between the metal and the carbene carbon, as confirmed by the extended Hückel calculations.The carbene functionality has been removed from the iron center in the reaction with O2 and HCl. The proposedstructures have been supported by X-ray analyses of complexes 8, 9, 12, 14, 16, 17, and 19.