Palladium−Arene Interactions in Catalytic Intermediates: An Experimental and Theoretical Investigation of the Soft Rearrangement between η<sup>1</sup> and η<sup>2</sup> Coordination Modes
作者:Marta Catellani、Carlo Mealli、Elena Motti、Paola Paoli、Enrique Perez-Carreño、Paul S. Pregosin
DOI:10.1021/ja016587e
日期:2002.4.1
characterized by means of NMR spectroscopy. The compound [(C16H19)PdCl]2*CH2Cl2 with ortho and para methyl substituents at the arene has been characterized by means of X-ray diffraction techniques. The C(ipso) atom of the arene lies almost at the fourth planar coordination site of the metal [Pd-C(ipso) = 2.22(1) A (average)], and due to the arene's tilting, the substituted C(ortho) atom is relatively
已经合成了一系列二氯桥连的芳基双环庚基钯配合物,并通过核磁共振光谱对其进行了表征。在芳烃上具有邻和对甲基取代基的化合物[(C16H19)PdCl]2*CH2Cl2已通过X射线衍射技术表征。芳烃的 C(ipso) 原子几乎位于金属的第四个平面配位点 [Pd-C(ipso) = 2.22(1) A(平均)],并且由于芳烃的倾斜,取代的 C(ortho ) 原子相对接近于金属原子 [2.54(1) A (average)]。协调的 C(ipso)-C(ortho) 键在看似二联配位中,相对于双环庚基单元的 CH2 桥是反的。对位取代二聚体 9 的变温 NMR 实验揭示了两个芳基关于相应 CC(ipso) 键的限制旋转 (DeltaE < 或 =17 kcal x mol(-1))。DFT-B3LYP 计算已在已知和类似的单体(苯基双环庚烯基)Pd(PPh3)I (4) 及其相关取代衍生物上进行。基本结果如下: