Wang Huizhu, Liu Jin-Kui, Wang Yi-Dong, Hao Xin-Qi, Song Mao-Ping, Gong Jun-Fang, Jiang Hui
Pingyuan Laboratory, College of Chemistry, Zhengzhou University, Zhengzhou 450001, China.
Molecules. 2025 Mar 30;30(7):1530. doi: 10.3390/molecules30071530.
Several CNN pincer Pd(II) complexes including chiral complexes - with 2-phenyl-6-(oxazolinyl)pyridines and achiral ones - with -substituted-2-aminomethyl-6-phenylpyridines were prepared. In addition, the preparation of the achiral PCN pincer Pd(II) complexes - with aryl-based phosphinite-imine ligands and chiral - with aryl-based phosphinite-imidazoline ligands was also performed. Among them, the PCN Pd(II) pincers - were new complexes and were readily synthesized from commercially available materials in only two steps. The new complexes were characterized through elemental analyses, namely H NMR, C{H} NMR, and P{H} NMR spectroscopies. Furthermore, the molecular structure of complex was determined via X-ray single-crystal diffraction analysis. In the presence of EtAlCl, EtAlCl, or methylaluminoxane (MAO), the CNN pincer Pd(II) complexes and PCN pincer Pd(II) complexes exhibited excellent activities and monomer conversion rates in norbornene addition polymerization. Surprisingly, the CNN pincer Pd(II) complexes exhibited a higher conversion rate (99.5%) with EtAlCl as the cocatalyst, while the PCN pincer Pd(II) complexes showed a higher conversion rate (98.8%) with MAO.
制备了几种含CNN钳形结构的钯（II）配合物，包括含有2-苯基-6-（恶唑啉基）吡啶的手性配合物以及含有β-取代-2-氨基甲基-6-苯基吡啶的非手性配合物。此外，还制备了含有芳基次膦酸酯-亚胺配体的非手性PCN钳形钯（II）配合物以及含有芳基次膦酸酯-咪唑啉配体的手性PCN钳形钯（II）配合物。其中，PCN钯（II）钳形配合物是新型配合物，仅通过两步即可由市售材料轻松合成。通过元素分析对新配合物进行了表征，即1H NMR、13C{1H} NMR和31P{1H} NMR光谱。此外，通过X射线单晶衍射分析确定了配合物的分子结构。在EtAlCl2、EtAlCl3或甲基铝氧烷（MAO）存在下，CNN钳形钯（II）配合物和PCN钳形钯（II）配合物在降冰片烯加成聚合反应中表现出优异的活性和单体转化率。令人惊讶的是，以EtAlCl2作为助催化剂时，CNN钳形钯（II）配合物表现出更高的转化率（99.5%），而以MAO作为助催化剂时，PCN钳形钯（II）配合物表现出更高的转化率（98.8%）。
