- 作者: 段君佩 ; 鄭建鴻
- 作者服務機構: 清華大學化學系
- 中文摘要: The complexes [ C/sub 6/H/sub 6/O(CO/sub 2/CH/sub 3/)/sub 2/R ] PdI(PPh/sub 3/) (R=p-anisyl (4), m-anisyl (5), p- tolyl (6), phenyl (7), 1-naphthyl (8) and 2-thienyl (9)) were prepared by treating Pd(PPh/sub 3/)/sub 2/(R)I with exo-5,6-dicarbomethoxy -7-oxanorbornene (3) or from the reaction of Pd(PPh/sub 3/)/sub 4/ with the corresponding organic iodide (RI) followed by addition of (3) and methyl iodide. In complexes (4-8), the carbon-carbon double bond between ipso and ortho positions of the aryl ring attached to the 7-oxanorbornyl group is weakly bound to the palladium (II) center in a .eta./sup 2/ fashion, in addition to the three ligands-the 7-oxanorbornyl group, PPh/sub 3/, and I/sup -/. This .eta./sup 2/-interaction leads to a dramatic upfield shift of /sup 13/C NMR signals of the ipso carbons by 30-40ppm. Variable-temperature NMR studies indicate that complexes (4-7) are nonrigid on the NMR time scale. Rotation of the weakly .eta./sup 2/-bound aryl group is proposed to account for the observed fluxional behavior. In contrast to (4-7), (8) is static at room temperature, presumably, due to the unsymmetrical nature and the large size of the naphthyl group. In complex(9), the sulfur atom in the thienyl group is coordinated to the palladium center and no intramolecular .eta./sup 2/- bonding is involved.
- 英文摘要: --
- 中文關鍵字: Arene Complex; Synthesis; Oxanorbornene; Insertion; Palladium Complex
- 英文關鍵字: 芳烴錯合物;合成;插入;鈀錯合物