The Dynamics of the β-Agostic Isopropyl Complex (ArNC(R)−C(R)NAr)Pd(CH(CH2-μ-H)(CH3))+BAr4‘- (Ar = 2,6-C6H3(i-Pr)2): Evidence for In-Place Rotation versus Dissociation of the Agostic Methyl Group
The Dynamics of the β-Agostic Isopropyl Complex (ArNC(R)−C(R)NAr)Pd(CH(CH2-μ-H)(CH3))+BAr4‘- (Ar = 2,6-C6H3(i-Pr)2): Evidence for In-Place Rotation versus Dissociation of the Agostic Methyl Group
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β-不规则异丙基配合物 (ArNC(R)−C(R)NAr)Pd(CH(CH2-μ-H)(CH3))+BAr4- (Ar = 2,6-C6H3(i-) 的动力学Pr)2)：原位旋转与不自由甲基解离的证据
DOI：
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发表时间：
1998
期刊：
影响因子：
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通讯作者：
M. Brookhart
中科院分区：
文献类型：
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作者：
D. J. Tempel;M. Brookhart
用变温~1H和~(13)C核磁共振研究了β-异丙基络合物(ArNC(R)−C(R)NAR)Pd(CH(CH_2-μ-H)(CH_3))+BAr4‘-(Ar=2，6-C_6H_3(i-Pr)_2)的动力学。~1H和~(13)C线形分析表明，发生了两个独立的过程：无胶甲基和非无胶甲基的 交换和无胶甲基内的氢交换，这最好地被认为是原位甲基旋转。这两个过程的势垒是相似的，ΔG⧧约为9千卡/摩尔。甲基在Pd(II)中心发生交换而不反转。
Variable-temperature 1H and 13C NMR spectroscopy has been used to study the dynamics of the β-agostic isopropyl complex (ArNC(R)−C(R)NAr)Pd(CH(CH2-μ-H)(CH3))+BAr4‘- (Ar = 2,6-C6H3(i-Pr)2). 1H and 13C line shape analysis suggests two independent processes occur: interchange of the agostic and nonagostic methyl groups and exchange of hydrogens within the agostic methyl group, which is best regarded as in-place methyl group rotation. Barriers for both of these processes are similar, with ΔG⧧ ca. 9 kcal/mol. The methyl groups undergo interchange without inversion at the Pd(II) center.