Substitution of Tetracyanoethene by Ethynyl鈥揗etal Complexes Gives Tricyanovinylethynyl (Tricyanobutenynyl) Derivatives: Syntheses, Protonation, and Addition of Metal鈥揕igand Fragments
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- 作者：Michael I. Bruce ; Mark A. Fox ; Paul J. Low ; Brian K. Nicholson ; Christian R. Parker ; Wyona C. Patalinghug ; Brian W. Skelton ; Allan H. White
- 刊名：Organometallics
- 出版年：2012
- 出版时间：April 9, 2012
- 年：2012
- 卷：31
- 期：7
- 页码：2639-2657
- 全文大小：867K
- 年卷期：v.31,no.7(April 9, 2012)
- ISSN：1520-6041
文摘
A series of complexes containing the new tricyanovinylethynyl (3,4,4-tricyanobut-3-en-1-ynyl) ligand have been obtained by substitution of a CN group in tetracyanoethene upon reaction with the ethynyl complexes M(C鈮H)(PP)Cp鈥?(M = Ru, Os, (PP)Cp鈥?= (PPh3)2Cp; M = Ru, PP = dppe, Cp鈥?= Cp, Cp*). The reactions proceed in higher yield as the metal environment becomes more sterically hindered, the normal [2 + 2]-cycloaddition/ring-opened product M{C[鈺怌(CN)2]CH鈺怌(CN)2}(PP)Cp鈥?also being formed in some cases. The diynyl complex Ru(C鈮C鈮H)(dppe)Cp* reacts with tcne to give only the ring-opened adduct Ru{C鈮C[鈺怌(CN)2]CH鈺怌(CN)2}(dppe)Cp*. Protonation (HBF4 or HPF6) of Ru{C鈮C(CN)鈺怌(CN)2}(dppe)Cp* afforded the vinylidene cation [Ru{鈺怌鈺怌HC(CN)鈺怌(CN)2}(dppe)Cp*]+. A second transition-metal fragment MLn (MLn = Ru(PPh3)2Cp, M鈥?dppe)Cp* (M鈥?= Ru, Os), RuCl(dppe)2) can be added to the CN group trans to the metal center; electrochemical, spectroscopic, and computational studies indicate that there is little ground-state delocalization between the metal centers. In the case of the tricyanovinylethynyl derivatives, an intense MLCT (or ML鈥擫CT) transition can be identified in the visible region, which is responsible for the intense blue to purple color of these species; the analogous transition in the vinylidene-based complexes is significantly blue-shifted. The X-ray crystallographically determined structures of several of these complexes are reported. The cations [{Cp*(dppe)Ru}{渭-(C/N)鈮C(CN)鈺怌(CN)(鈮/N)}{M(dppe)Cp*}]+ (M = Ru, Os) show some C鈮/C鈮 disorder (and associated Ru/Os disorder in the case of the heterometallic example) in the crystals.