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Kinetic Study of Living Ring-Opening Metathesis Polymerization with Third-Generation Grubbs Catalysts
Journal of the American Chemical Society ( IF 14.4 ) Pub Date : 2017-09-25 , DOI: 10.1021/jacs.7b08010 Dylan J. Walsh 1 , Sii Hong Lau 1 , Michael G. Hyatt 2 , Damien Guironnet 1
Journal of the American Chemical Society ( IF 14.4 ) Pub Date : 2017-09-25 , DOI: 10.1021/jacs.7b08010 Dylan J. Walsh 1 , Sii Hong Lau 1 , Michael G. Hyatt 2 , Damien Guironnet 1
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The rate of living ring-opening metathesis polymerization (ROMP) of N-hexyl-exo-norbornene-5,6-dicarboximide initiated by Grubbs third-generation catalyst precursors [(H2IMes)(py)2(Cl)2Ru═CHPh] and [(H2IMes)(3-Br-py)2(Cl)2Ru═CHPh] is measured to be independent of catalyst concentration. This result led to the development of a rate law describing living ROMP initiated by a Grubbs third-generation catalyst that includes an inverse first-order dependency in pyridine. Additionally, it is demonstrated that one of the two pyridines coordinated to the solid catalyst is fully dissociated in solution. The monopyridine adduct formation is confirmed in solution by 1H DOSY (diffusion-ordered NMR spectroscopy), and a Van't Hoff analysis of the equilibrium between mono- and dipyridine adducts (extrapolated Keq,0 ∼ 0.5 at 25 °C). Finally, the difference in polymerization rates between two catalyst precursors is demonstrated to correspond to the difference in coordination strength between the two pyridines, suggesting that the catalytic species involved in the polymerization's rate-determining step is not coordinated to pyridine.
中文翻译：
第三代Grubbs催化剂活性开环复分解聚合的动力学研究
由 Grubbs 第三代催化剂前体 [(H2IMes)(py)2(Cl)2Ru=CHPh] 引发的 N-hexyl-exo-norbornene-5,6-dicarboximide 的活性开环复分解聚合 (ROMP) 的速率[(H2IMes)(3-Br-py)2(Cl)2Ru=CHPh] 经测量与催化剂浓度无关。这一结果导致了速率定律的发展，该定律描述了由 Grubbs 第三代催化剂引发的活性 ROMP，其中包括对吡啶的反向一级依赖性。此外，证明与固体催化剂配位的两种吡啶之一在溶液中完全离解。单吡啶加合物的形成在溶液中通过 1H DOSY（扩散有序 NMR 光谱）和单吡啶加合物和双吡啶加合物之间的平衡的 Van't Hoff 分析（外推的 Keq，0 ～ 0.5 在 25 °C 下）确认。最后，
更新日期：2017-09-25
中文翻译：
第三代Grubbs催化剂活性开环复分解聚合的动力学研究
由 Grubbs 第三代催化剂前体 [(H2IMes)(py)2(Cl)2Ru=CHPh] 引发的 N-hexyl-exo-norbornene-5,6-dicarboximide 的活性开环复分解聚合 (ROMP) 的速率[(H2IMes)(3-Br-py)2(Cl)2Ru=CHPh] 经测量与催化剂浓度无关。这一结果导致了速率定律的发展，该定律描述了由 Grubbs 第三代催化剂引发的活性 ROMP，其中包括对吡啶的反向一级依赖性。此外，证明与固体催化剂配位的两种吡啶之一在溶液中完全离解。单吡啶加合物的形成在溶液中通过 1H DOSY（扩散有序 NMR 光谱）和单吡啶加合物和双吡啶加合物之间的平衡的 Van't Hoff 分析（外推的 Keq，0 ～ 0.5 在 25 °C 下）确认。最后，
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