Synthesis, Characterization, and Comparative Study on Norbornene Polymerization of CNN and PCN Pincer Palladium Complexes
Several CNN pincer Pd(II) complexes including chiral complexes <b>1a</b>–<b>e</b> with 2-phenyl-6-(oxazolinyl)pyridines and achiral ones <b>2a</b>–<b>c</b> with <i>N</i>-substituted-2-aminomethyl-6-phenylpyridines were prepared. In addition...
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MDPI AG
2025-03-01
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| Series: | Molecules |
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| Online Access: | https://www.mdpi.com/1420-3049/30/7/1530 |
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| author | Huizhu Wang Jin-Kui Liu Yi-Dong Wang Xin-Qi Hao Mao-Ping Song Jun-Fang Gong Hui Jiang |
| author_facet | Huizhu Wang Jin-Kui Liu Yi-Dong Wang Xin-Qi Hao Mao-Ping Song Jun-Fang Gong Hui Jiang |
| author_sort | Huizhu Wang |
| collection | DOAJ |
| description | Several CNN pincer Pd(II) complexes including chiral complexes <b>1a</b>–<b>e</b> with 2-phenyl-6-(oxazolinyl)pyridines and achiral ones <b>2a</b>–<b>c</b> with <i>N</i>-substituted-2-aminomethyl-6-phenylpyridines were prepared. In addition, the preparation of the achiral PCN pincer Pd(II) complexes <b>3a</b>–<b>e</b> with aryl-based phosphinite–imine ligands and chiral <b>4a</b>–<b>c</b> with aryl-based phosphinite–imidazoline ligands was also performed. Among them, the PCN Pd(II) pincers <b>3a</b>–<b>e</b> were new complexes and were readily synthesized from commercially available materials in only two steps. The new complexes were characterized through elemental analyses, namely <sup>1</sup>H NMR, <sup>13</sup>C{<sup>1</sup>H} NMR, and <sup>31</sup>P{<sup>1</sup>H} NMR spectroscopies. Furthermore, the molecular structure of complex <b>3a</b> was determined via X-ray single-crystal diffraction analysis. In the presence of EtAlCl<sub>2</sub>, Et<sub>2</sub>AlCl, 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 Et<sub>2</sub>AlCl as the cocatalyst, while the PCN pincer Pd(II) complexes showed a higher conversion rate (98.8%) with MAO. |
| format | Article |
| id | doaj-art-0a58cf6b44f64a7da5fe1690ef9aeeee |
| institution | OA Journals |
| issn | 1420-3049 |
| language | English |
| publishDate | 2025-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Molecules |
| spelling | doaj-art-0a58cf6b44f64a7da5fe1690ef9aeeee2025-08-20T02:09:14ZengMDPI AGMolecules1420-30492025-03-01307153010.3390/molecules30071530Synthesis, Characterization, and Comparative Study on Norbornene Polymerization of CNN and PCN Pincer Palladium ComplexesHuizhu Wang0Jin-Kui Liu1Yi-Dong Wang2Xin-Qi Hao3Mao-Ping Song4Jun-Fang Gong5Hui Jiang6Pingyuan Laboratory, College of Chemistry, Zhengzhou University, Zhengzhou 450001, ChinaPingyuan Laboratory, College of Chemistry, Zhengzhou University, Zhengzhou 450001, ChinaPingyuan Laboratory, College of Chemistry, Zhengzhou University, Zhengzhou 450001, ChinaPingyuan Laboratory, College of Chemistry, Zhengzhou University, Zhengzhou 450001, ChinaPingyuan Laboratory, College of Chemistry, Zhengzhou University, Zhengzhou 450001, ChinaPingyuan Laboratory, College of Chemistry, Zhengzhou University, Zhengzhou 450001, ChinaPingyuan Laboratory, College of Chemistry, Zhengzhou University, Zhengzhou 450001, ChinaSeveral CNN pincer Pd(II) complexes including chiral complexes <b>1a</b>–<b>e</b> with 2-phenyl-6-(oxazolinyl)pyridines and achiral ones <b>2a</b>–<b>c</b> with <i>N</i>-substituted-2-aminomethyl-6-phenylpyridines were prepared. In addition, the preparation of the achiral PCN pincer Pd(II) complexes <b>3a</b>–<b>e</b> with aryl-based phosphinite–imine ligands and chiral <b>4a</b>–<b>c</b> with aryl-based phosphinite–imidazoline ligands was also performed. Among them, the PCN Pd(II) pincers <b>3a</b>–<b>e</b> were new complexes and were readily synthesized from commercially available materials in only two steps. The new complexes were characterized through elemental analyses, namely <sup>1</sup>H NMR, <sup>13</sup>C{<sup>1</sup>H} NMR, and <sup>31</sup>P{<sup>1</sup>H} NMR spectroscopies. Furthermore, the molecular structure of complex <b>3a</b> was determined via X-ray single-crystal diffraction analysis. In the presence of EtAlCl<sub>2</sub>, Et<sub>2</sub>AlCl, 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 Et<sub>2</sub>AlCl as the cocatalyst, while the PCN pincer Pd(II) complexes showed a higher conversion rate (98.8%) with MAO.https://www.mdpi.com/1420-3049/30/7/1530CNN pincerPCN pincerpalladium-catalyzedvinyl-type polynorbornene |
| spellingShingle | Huizhu Wang Jin-Kui Liu Yi-Dong Wang Xin-Qi Hao Mao-Ping Song Jun-Fang Gong Hui Jiang Synthesis, Characterization, and Comparative Study on Norbornene Polymerization of CNN and PCN Pincer Palladium Complexes Molecules CNN pincer PCN pincer palladium-catalyzed vinyl-type polynorbornene |
| title | Synthesis, Characterization, and Comparative Study on Norbornene Polymerization of CNN and PCN Pincer Palladium Complexes |
| title_full | Synthesis, Characterization, and Comparative Study on Norbornene Polymerization of CNN and PCN Pincer Palladium Complexes |
| title_fullStr | Synthesis, Characterization, and Comparative Study on Norbornene Polymerization of CNN and PCN Pincer Palladium Complexes |
| title_full_unstemmed | Synthesis, Characterization, and Comparative Study on Norbornene Polymerization of CNN and PCN Pincer Palladium Complexes |
| title_short | Synthesis, Characterization, and Comparative Study on Norbornene Polymerization of CNN and PCN Pincer Palladium Complexes |
| title_sort | synthesis characterization and comparative study on norbornene polymerization of cnn and pcn pincer palladium complexes |
| topic | CNN pincer PCN pincer palladium-catalyzed vinyl-type polynorbornene |
| url | https://www.mdpi.com/1420-3049/30/7/1530 |
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