Half-Sandwich Hydride Complexes of Ruthenium with Bidentate Phosphinoamine Ligands: Proton-Transfer Reactions to [(C5R5)RuH(L)] [R = H, Me; L = dippae, (R,R)-dippac

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• 作者：Manuel Jim&eacute ; nez-Tenorio ; M. Dolores Palacios ; M. Carmen Puerta ; Pedro Valerga
• 刊名：Inorganic Chemistry
• 出版年：2007
• 出版时间：February 5, 2007
• 年：2007
• 卷：46
• 期：3
• 页码：1001 - 1012
• 全文大小：267K
• 年卷期：v.46,no.3(February 5, 2007)
• ISSN：1520-510X

文摘

The complexes [(C₅R₅)RuH(dippae)] [R = H (1a), Me (2a); dippae = 1,2-bis(diisopropylphosphinoamino)ethane]and [(C₅R₅)RuH((R,R)-dippach)] [R = H (1b), Me (2b); (R,R)-dippach = (R,R)-1,2-bis(diisopropylphosphinoamino)cyclohexane] have been prepared and characterized. The cationic ruthenium(IV) dihydride derivatives [(C₅R₅)RuH₂(dippae)][BPh₄] [R = H (3a), Me (4a)] and [(C₅R₅)RuH₂((R,R)-dippach)][BPh₄] [R = H (3b), Me (4b)] are alsoreported. No significant intramolecular interaction between the amino protons and the hydrogen atoms bound tothe metal has been observed in any of these compounds. The X-ray crystal structure of 4a was determined. Theproton-transfer processes over the monohydrides 2a and 2b with HBF₄·OEt₂ have been studied by NMR spectroscopy.Dicationic dihydride complexes [CpRuH₂(LH)]²⁺ [LH = dippaeH⁺ (5a), (R,R)-dippachH⁺ (5b)] and [Cp*RuH₂(LH)]²⁺[LH = dippaeH⁺ (6a), (R,R)-dippachH⁺ (6b)] result respectively from the protonation of either the monohydrides1a,b or 2a,b or the dihydrides 3a,b or 4a,b at one of the NH groups of the phosphinoamine ligands by an excessof HBF₄. These dicationic derivatives exhibit fluxional behavior in solution. In the course of the protonation of 1awith HBF₄·OEt₂, a cationic dihydrogen complex and a dihydrogen-bonded derivative have been identified asintermediates by NMR spectroscopy. Another dihydrogen species, namely, [CpRu(H···HOOCPh)((R,R)-dippach)],was also identified in the course of the reaction of 1b with benzoic acid in toluene-d₈. The reaction of 1a with 0.5equiv of 1,1,1,3,3,3-hexafluoroisopropanol generates a hydride species having a very short (T₁)_min of 6.5 ms at 400MHz, an experimental fact for which no satisfactory explanation has yet been found.