Carbene Iridium(I) and Iridium(III) Complexes Containing the Metal Center in Different Stereochemical Environments
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- 作者：Dagmara A. Ortmann ; Birgit Weberndö ; rfer ; Kerstin Ilg ; Matthias Laubender ; and Helmut Werner
- 刊名：Organometallics
- 出版年：2002
- 出版时间：June 10, 2002
- 年：2002
- 卷：21
- 期：12
- 页码：2369 - 2381
- 全文大小：216K
- 年卷期：v.21,no.12(June 10, 2002)
- ISSN：1520-6041
文摘
The mixed-ligand complex [IrCl(C2H4)(SbiPr3)(PiPr3)] (2), prepared from [IrCl(C2H4)(PiPr3)]2 (1) and SbiPr3, reacts not only with CO, diphenylacetylene, and H2 by ligandsubstitution or oxidative addition but also with diaryldiazomethanes R2CN2 to give the four-coordinate iridium(I) carbenes [IrCl(=CR2)(SbiPr3)(PiPr3)] (8-10) in 60-70% isolated yield.In contrast, treatment of 2 and of the related cyclooctene derivative trans-[IrCl(C8H14)(SbiPr3)2] (12) with C5Cl4N2 affords the diazoalkane complexes trans-[IrCl(N2C5Cl4)(SbiPr3)(EiPr3)] (11, E = P; 13, E = Sb) without elimination of N2. Displacement of the stibine ligandin 8-10 by PiPr3 leads to the corresponding bis(phosphine) compounds trans-[IrCl(=CR2)(PiPr3)2] (14-16), while the reaction of 8 (R = C6H5) with NaC5H5 yields the half-sandwich-type complex [(
5-C5H5)Ir(=CPh2)(PiPr3)] (17). Protonation of 17 with HCl occurs stepwiseto give via the iridium(III) alkyl [(5-C5H5)IrCl(CHPh2)(PiPr3)] (20) the ring-substitutedisomer [(5-C5H4CHPh2)IrHCl(PiPr3)] (21); however, if 17 is treated with HBF4, a cationiccomplex is formed which probably contains a 3-coordinated benzylic ligand. The square-planar iridium(I) carbenes 8 and 14 react with HBX4 (X = F, ArF) to afford the ionic products[IrHCl(=CPh2)(PiPr3)(EiPr3)]BX4 (23, 24, E = P; 25, E = Sb) and with HCl to give therelatively labile octahedral species [IrHCl2(=CPh2)(PiPr3)(EiPr3)] (26, E = P; 27, E = Sb).Treatment of 8 and 14 with ethene yields, besides [IrCl(C2H4)2(SbiPr3)2] (18) and/or trans-[IrCl(C2H4)(PiPr3)2] (28), a mixture of two isomeric olefinic products CH2=CHCHPh2 (29)and CH3CH=CPh2 (30), the ratio of which is independent of the ligand sphere of the iridiumprecursor. The molecular structures of 13, 14, 17, and 24 have been determined by X-raycrystallography.
5-C5H5)Ir(=CPh2)(PiPr3)] (17). Protonation of 17 with HCl occurs stepwiseto give via the iridium(III) alkyl [(5-C5H5)IrCl(CHPh2)(PiPr3)] (20) the ring-substitutedisomer [(5-C5H4CHPh2)IrHCl(PiPr3)] (21); however, if 17 is treated with HBF4, a cationiccomplex is formed which probably contains a 3-coordinated benzylic ligand. The square-planar iridium(I) carbenes 8 and 14 react with HBX4 (X = F, ArF) to afford the ionic products[IrHCl(=CPh2)(PiPr3)(EiPr3)]BX4 (23, 24, E = P; 25, E = Sb) and with HCl to give therelatively labile octahedral species [IrHCl2(=CPh2)(PiPr3)(EiPr3)] (26, E = P; 27, E = Sb).Treatment of 8 and 14 with ethene yields, besides [IrCl(C2H4)2(SbiPr3)2] (18) and/or trans-[IrCl(C2H4)(PiPr3)2] (28), a mixture of two isomeric olefinic products CH2=CHCHPh2 (29)and CH3CH=CPh2 (30), the ratio of which is independent of the ligand sphere of the iridiumprecursor. The molecular structures of 13, 14, 17, and 24 have been determined by X-raycrystallography.