Carborane Complexes of Ruthenium: Studies on the Chemistry of the Ru(CO)2(5-7,8-C2B9H

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• 作者：Stephen Anderson ; Donald F. Mullica ; Eric L. Sappenfield ; and F. Gordon A. Stone
• 刊名：Organometallics
• 出版年：1996
• 出版时间：March 19, 1996
• 年：1996
• 卷：15
• 期：6
• 页码：1676 - 1689
• 全文大小：436K
• 年卷期：v.15,no.6(March 19, 1996)
• ISSN：1520-6041

文摘

Treatment of[Ru(CO)₃(⁵-7,8-C₂B₉H₁₁)](1) with Me₃NO in THF (tetrahydrofuran)affords[Ru(CO)₂(NMe₃)(⁵-7,8-C₂B₉H₁₁)](3b), while the salt[NEt₄][RuI(CO)₂(⁵-7,8-C₂B₉H₁₁)](2)reacts with NCMe in the presence of AgBF₄ to give[Ru(CO)₂(NCMe)(⁵-7,8-C₂B₉H₁₁)](3c).Related complexes[Ru(CO)₂(L)(⁵-7,8-C₂B₉H₁₁)](L = CNBu^t (3d), PPh₃(3e)) are obtainedby displacement of THF from[Ru(CO)₂(THF)(⁵-7,8-C₂B₉H₁₁)](3a) with CNBu^t andPPh₃,respectively. Alkenes and 3a afford the complexes[Ru(CO)₂(alkene)(⁵-7,8-C₂B₉H₁₁)](alkene= C₂H₄ (4a),MeCH=CH₂ (4b),Me₃SiCH=CH₂ (4c), andC₇H₁₀ (norbornene) (4d)),whereasalkynes RCCR (R = Me, Ph) give the species[Ru(CO)₂(RCCR)(⁵-7,8-C₂B₉H₁₁)](R = Me(5a), Ph (5b)). The reaction of complex5a with K[BH(CHMeEt)₃], inEt₂O solution, followedby addition of 18-crown-6, gives the salt[K(18-crown-6)][Ru{C(Me)=C(H)Me}(CO)₂(⁵-7,8-C₂B₉H₁₁)] (6), whilePPh₃ in CH₂Cl₂ affords theylide complex[Ru{C(Me)=C(Me)PPh₃}(CO)₂(⁵-7,8-C₂B₉H₁₁)](7). Reactions between 3a and the alkynesRCCH (R = Bu^t, SiMe₃) yielda variety of products, in all of which the carborane ligand adopts anonspectator role.Complex 3a and 1 mol equiv of Bu^tCCHgives a mixture of isomers[Ru(CO)₂(²:⁵-9-C(H)=C(H)Bu^t-7,8-C₂B₉H₁₀)](8a) and[Ru(CO)₂(²:⁵-10-C(H)=C(H)Bu^t-7,8-C₂B₉H₁₀)](8b).An X-ray diffraction study on 8a revealed that theruthenium atom is ⁵-coordinated by theopen CCBBB face of thenido-C₂B₉ cage and by the C=C bondof the BCH=C(H)Bu^t group.The reaction between 3a and 1 mol equiv ofMe₃SiCCH is more complex due toSiMe₃group cleavage. Isomeric mixtures of[Ru(CO)₂(²:⁵-9-C(H)=C(H)R-7,8-C₂B₉H₁₀)](R = H(9a), SiMe₃ (10a)) and[Ru(CO)₂(²:⁵-10-C(H)=C(H)R-7,8-C₂B₉H₁₀)](R = H (9b), SiMe₃(10b))are obtained. Addition of PMe₂Ph in heptane to9b gives[Ru(CO)₂(,⁵-10-C(H)(PMe₂Ph)CH₂-7,8-C₂B₉H₁₀)](11b), the ylide structure of which was confirmed by X-raycrystallography.The Ru(CO)₂ fragment is linked to thenido-C₂B₉ cage system by⁵ bonding to the CCBBBface and by a Ru-CH₂ -bond to theCH₂C(H)(PMe₂Ph)B fragment. Reactionsbetween 3aand RCCH, employing an excess of the latter, give the compounds[Ru(CO)₂{²:⁵-9-C(H)=C(H)R-10,11-[C(H)=C(H)R]₂-7,8-C₂B₉H₈}](R = Bu^t (12a), SiMe₃(12b)) in which allboron atoms in the open CCBBB face of the cage bonded tothe ruthenium carry C(H)=C(H)R substituents. Treatment of the complexes 12 withPMe₃ yields respectively[Ru(CO)₂(PMe₃){⁵-9,10,11-[C(H)=C(H)Bu^t]₃-7,8-C₂B₉H₈}](13) and[Ru(CO)₂{,⁵-9-C(H)(PMe₃)C(H)SiMe₃-10,11-[C(H)=C(H)SiMe₃]₂-7,8-C₂B₉H₈}](14). The structure of 13 wasestablishedby X-ray diffraction. The Ru atom is coordinated by aPMe₃ molecule and the two CO groupsand by thenido-9,10,11-[C(H)=C(H)Bu^t]₃-7,8-C₂B₉H₈cage. All boron atoms in the pentagonalCCBBB ring ligating the metal carryC(H)=C(H)Bu^t substituents. In addition toX-raycrystal structure determinations, NMR data for the new complexes arereported and discussedin relation to their structures.