| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1337502 | Polyhedron | 2015 | 14 Pages |
The construction of a series of compounds {Ru(dppe)Cp∗}2(μ-C2x) (Ru∗-C2x-Ru∗, x = 4–8, 11)) is described. A direct reaction between RuCl(dppe)Cp∗ and Me3Si(CC)4SiMe3 afforded Ru∗-C8-Ru∗ in 89% yield. The Pd(0)/Cu(I)-catalysed coupling of Ru{CCCCAu(PPh3)}(dppe)Cp∗Ru∗-C4-Au (2 equiv.) with diiodoethyne gave Ru∗-C10-Ru∗ (64%), or of 1 equiv. with I(CC)3I gave Ru∗-C14-Ru∗ (36%); similarly, Ru{(CC)4Au(PPh3)}(dppe)Cp∗Ru∗-C8-Au and I(CC)3I gave Ru∗-C22-Ru∗ (12%). Desilylation (TBAF) of Ru{(CC)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(CCCCH)(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(CC)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-CCC[Ru(dppe)Cp∗]}2Fe(C3-Ru∗)2 and {Fe3(CO)9}{μ3-CCC[Ru(dppe)Cp∗]}{μ3-C(CC)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-(CC)4}·4CHCl3Ru-C8-Ru·4CHCl3 and of Fe(C3-Ru∗)2 and Fe(C3-Ru∗)(C5-Ru∗) are reported.
Graphical abstractPd(0)/Cu(I)-catalysed reactions between iodo- or diiodo-alkynes and (phosphine)gold-substituted alkynyl-ruthenium complexes have given {Ru(dppe)Cp∗}2{ μ -(CC)x} (x = 4–8, 11). Their redox properties have been measured, and seven X-ray structures are described.Figure optionsDownload full-size imageDownload as PowerPoint slide
