Kinetics and Mechanism of Ligand Exchange in Photogenerated (η2-monoalkylarene)Cr(CO)5 Complexes with Alkenes: Evidence for Involvement of Aliphatic Chains in the Arene and Alkene in the Exchange Process
Kinetics and Mechanism of Ligand Exchange in Photogenerated (η2-monoalkylarene)Cr(CO)5 Complexes with Alkenes: Evidence for Involvement of Aliphatic Chains in the Arene and Alkene in the Exchange Process
复制标题
光生 (η2-单烷基芳烃)Cr(CO)5 与烯烃配合物中配体交换的动力学和机制：芳烃和烯烃中脂肪链参与交换过程的证据
DOI：
10.1021/om970041c
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
G. Dobson
中科院分区：
文献类型：
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作者：
Santino Ladogana;S. K. Nayak;Jaap P. Smit;G. Dobson
光生 (η2-C6H5R)Cr(CO)5 配合物 (R = CH3, C2H5, i-C3H7, t-C4H9, c-C6H11, (C6H5)(CH2)11CH3) 的反应动力学和机理，其中 C6H5R 是与 Cr (Lw) 弱键合的配体，具有强配位“捕获”亲核试剂，其中包含烯属官能团（Ls = 1-己烯、1-癸烯和 1-十四碳烯）已通过采用脉冲激光闪光光解以及可见光和红外检测进行了研究。取代的芳烃分子可能通过环中部分离域的不饱和中心与金属“边缘”键合。 “纯”至非常高 [Ls] 和“惰性”溶剂 (S) 稀溶液中的动力学数据非常一致，表明 S（C6H5R、氟苯、正庚烷）的影响相对不重要。动力学数据与涉及 C6H5R 从 (η2-C6H5R)Cr(CO)5 解离，然后与 C6H5R 或 Ls 产生的 [Cr(CO)5] 中间体进行竞争反应的单一机制完全一致。 C 的速率常数 k1 的变化...
The kinetics and mechanism of the reaction of photogenerated (η2-C6H5R)Cr(CO)5 complexes (R = CH3, C2H5, i-C3H7, t-C4H9, c-C6H11, (C6H5)(CH2)11CH3), in which C6H5R is a ligand weakly bonded to Cr (Lw), with strongly coordinating “trapping” nucleophiles containing an olefinic functionality (Ls = 1-hexene, 1-decene, and 1-tetradecene) have been studied by employing pulsed laser flash photolysis with visible and infrared detection. The substituted arene molecules likely bond to the metal “edge-on” via a partially delocalized center of unsaturation in the ring. Kinetics data taken “neat” to very high [Ls] and in dilute solution in the “inert” solvents (S) agree closely, indicating that influences of S (C6H5R, fluorobenzene, n-heptane) are relatively unimportant. The kinetics data are wholly consistent with a single mechanism involving dissociation of C6H5R from (η2-C6H5R)Cr(CO)5, followed by competitive reaction of the [Cr(CO)5] intermediate thus produced with C6H5R or Ls. Changes in rate constants, k1, for C...