The series of carbon-chain complexes {Ru(dppe)Cp*}₂{μ-(C≡C_)x} (x = 4–8, 11): Synthesis, structures, properties and some reactions

Journal Article · Wed Jan 28 00:00:00 EST 2015 · Polyhedron

DOI:https://doi.org/10.1016/j.poly.2014.04.052· OSTI ID:1171266

Bruce, Michael I. ^[1]; Cole, Marcus L. ^[1]; Ellis, Benjamin G. ^[1]; Gaudio, Maryka ^[1]; Nicholson, Brian K. ^[2]; Parker, Christian R. ^[1]; Skelton, Brian W. ^[3]; White, Allan H. ^[3]

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1. Univ. of Adelaide, South Australia (Australia)
2. Univ. of Waikato, Hamilton (New Zealand)
3. Univ. of Western Australia, Crawley (Western Australia)

The construction of a series of compounds {Ru(dppe)Cp*}₂(μ-C_2x) (Ru*-C2x-Ru*, x = 4–8, 11)) is described. A direct reaction between RuCl(dppe)Cp* and Me₃Si(Ctriple bond; length of mdashC)₄SiMe₃ afforded Ru*-C8-Ru* in 89% yield. The Pd(0)/Cu(I)-catalysed coupling of Ru{Ctriple bond; length of mdashCCtriple bond; length of mdashCAu(PPh₃)}(dppe)Cp*Ru*-C4-Au (2 equiv.) with diiodoethyne gave Ru*-C10-Ru* (64%), or of 1 equiv. with I(Ctriple bond; length of mdashC)₃I gave Ru*-C14-Ru* (36%); similarly, Ru{(Ctriple bond; length of mdashC)₄Au(PPh₃)}(dppe)Cp*Ru*-C8-Au and I(Ctriple bond; length of mdashC)₃I gave Ru*-C22-Ru* (12%). Desilylation (TBAF) of Ru{(Ctriple bond; length of mdashC)xSiMe₃}(dppe)Cp*Ru*-C2x-Si (x = 3, 4) followed by oxidative coupling [Cu(OAc)₂/py] gave Ru*-C12-Ru* (82%) and Ru*-C16-Ru* (58%), respectively. Similar oxidative coupling of Ru(Ctriple bond; length of mdashCCtriple bond; length of mdashCH)(dppe)Cp* was a second route to Ru*-C8-Ru* (82%). Appropriate precursors are already known, or obtained by coupling of Ru*-C2x-Si (x = 2, 4) with AuCl(PPh₃)/NaOMe [Ru*-C4-Au, 95%; Ru*-C8-Au, 74%] or from Pd(0)/Cu(I) catalysed coupling of Ru*-C2x-Au (x = 2, 3) with I(Ctriple bond; length of mdashC)₂SiMe₃ (Ru*-C8-Si, 64%; Ru*-C10-Si, 2%). Reactions between Ru*-C2x-Ru* (x = 3, 4) and Fe₂(CO)₉ gave {Fe₃(CO)₉}{μ₃-CCtriple bond; length of mdashC[Ru(dppe)Cp*]}₂Fe(C₃-Ru*)₂ and {Fe₃(CO)₉}{μ₃-CCtriple bond; length of mdashC[Ru(dppe)Cp*]}{μ₃-C(Ctriple bond; length of mdashC)₂[Ru(dppe)Cp*]} Fe(C₃-Ru*)(C₅-Ru*), respectively. The redox properties of the series of complexes with 2x = 2–16 were measured and showed a diminution of the separation of the first two oxidation potentials, ΔE = E₂ - E₁, with increasing carbon chain length. The X-ray-determined molecular structures of Ru*-C8-Si, Ru*-C8-Ru*, Ru*-C14-Ru* (two C₆H₆ solvates), {Ru(PPh₃)₂Cp}₂{μ-(Ctriple bond; length of mdashC)₄}·4CHCl₃Ru-C₈-Ru·4CHCl₃ and of Fe(C₃-Ru*)₂ and Fe(C₃-Ru*)(C₅-Ru*) are reported.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL (United States). Advanced Photon Source (APS).
• Sponsoring Organization: USDOE
• OSTI ID: 1171266
• Journal Information: Polyhedron, Vol. 86, Issue C; ISSN 0277-5387
• Publisher: Elsevier
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

Ruthenium
carbon-chain
X-ray structure
electrochemistry
carbyne