C7 and C9 Carbon-Rich Bridges in Diruthenium Systems: Synthesis, Spectroscopic, and Theoretical Investigations of Different Oxidation States
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- 作者：Sté ; phane Rigaut ; Cé ; line Olivier ; Karine Costuas ; Sylvie Choua ; Omrane Fadhel ; Julien Massue ; Philippe Turek ; Jean-Yves Saillard ; Pierre H. Dixneuf ; and Daniel Touchard
- 刊名：Journal of the American Chemical Society
- 出版年：2006
- 出版时间：May 3, 2006
- 年：2006
- 卷：128
- 期：17
- 页码：5859 - 5876
- 全文大小：537K
- 年卷期：v.128,no.17(May 3, 2006)
- ISSN：1520-5126
文摘
Two methodologies of C-C bond formation to achieve organometallic complexes with 7 or 9 conjugated carbon atoms are described. A C7 annelated 53a10001">trans-[Cl(dppe)2Ru=C=C=C-CH=C( CH2)-C
C-Ru(dppe)2Cl][X] (X = PF6, OTf) complex is obtained from the diyne trans-[Cl(dppe)2Ru-(CC)2-R] (R =H, SiMe3) in the presence of [FeCp2][PF6] or HOTf, and C7 or C9 complexes trans-[Cl(dppe)2Ru-(CC)n-C(CH3)=C(R1)-C(R2)=C=C=Ru(dppe)2Cl][X] (n = 1, 2; R1 = Me, Ph, R2 = H, Me; X = BF4, OTf) areformed in the presence of a polyyne trans-[Cl(dppe)2Ru-(CC)n-R] (n = 2, 3; R = H, SiMe3) with aruthenium allenylidene trans-[Cl(dppe)2Ru=C=C=C(CH2R1)R2][X]. These reactions proceed under mildconditions and involve cumulenic intermediates [M+]=(C=)nCHR (n = 3, 5), including a hexapentaenylidene.A combination of chemical, electrochemical, spectroscopic (UV-vis, IR, NIR, EPR), and theoretical (DFT)techniques is used to show the influence of the nature and conformation of the bridge on the properties ofthe complexes and to give a picture of the electron delocalization in the reduced and oxidized states.These studies demonstrate that the C7 bridging ligand spanning the metal centers by almost 12 Å isimplicated in both redox processes and serves as a molecular wire to convey the unpaired electron withno tendency for spin localization on one of the halves of the molecules. The reactivity of the C7 complexestoward protonation and deprotonation led to original bis(acetylides), vinylidene-allenylidene, or carbyne-vinylidene species such as trans-[Cl(dppe)2RuC-CH=C(CH3)-CH=C(CH3)-HC=C=Ru(dppe)2Cl][BF4]3.
C-Ru(dppe)2Cl][X]C)2-R] (R =H, SiMe3) in the presence of [FeCp2][PF6] or HOTf, and C7 or C9 complexes trans-[Cl(dppe)2Ru-(CC)n-C(CH3)=C(R1)-C(R2)=C=C=Ru(dppe)2Cl][X] (n = 1, 2; R1 = Me, Ph, R2 = H, Me; X = BF4, OTf) areformed in the presence of a polyyne trans-[Cl(dppe)2Ru-(CC)n-R] (n = 2, 3; R = H, SiMe3) with aruthenium allenylidene trans-[Cl(dppe)2Ru=C=C=C(CH2R1)R2][X]. These reactions proceed under mildconditions and involve cumulenic intermediates [M+]=(C=)nCHR (n = 3, 5), including a hexapentaenylidene.A combination of chemical, electrochemical, spectroscopic (UV-vis, IR, NIR, EPR), and theoretical (DFT)techniques is used to show the influence of the nature and conformation of the bridge on the properties ofthe complexes and to give a picture of the electron delocalization in the reduced and oxidized states.These studies demonstrate that the C7 bridging ligand spanning the metal centers by almost 12 Å isimplicated in both redox processes and serves as a molecular wire to convey the unpaired electron withno tendency for spin localization on one of the halves of the molecules. The reactivity of the C7 complexestoward protonation and deprotonation led to original bis(acetylides), vinylidene-allenylidene, or carbyne-vinylidene species such as trans-[Cl(dppe)2RuC-CH=C(CH3)-CH=C(CH3)-HC=C=Ru(dppe)2Cl][BF4]3.