Easter Quinn T, Blum Suzanne A
Department of Chemistry, University of California, Irvine, Irvine, CA, 92697, USA.
Angew Chem Int Ed Engl. 2018 Sep 10;57(37):12027-12032. doi: 10.1002/anie.201807317. Epub 2018 Aug 7.
Essentially no information is known about the behavior of individual molecular catalysts under reaction conditions. This is a result of the averaging inherent to traditional analytical techniques. Herein, a combined fluorescence microscopy and H NMR spectroscopy study reveals that unique (that is, non-ensemble averaged) distributions and time-variable kinetics from molecular ruthenium catalysts within growing polynorbornene occur and are detectable between 10 m and 10 m of substrate, surprisingly just 1000-fold less concentrated than a typical laboratory bench-scale reaction. The kinetic states governing single-turnover events are determinable by overlay of the signal arising from individual monomer insertion reactions with that from polymer growth from neighboring catalysts.
关于单个分子催化剂在反应条件下的行为,基本上尚无信息。这是传统分析技术固有的平均化结果。在此,一项结合荧光显微镜和氢核磁共振光谱的研究表明,在生长的聚降冰片烯中,分子钌催化剂存在独特的(即非整体平均的)分布和随时间变化的动力学,并且在底物浓度为10⁻⁶ 摩尔/升至10⁻⁹ 摩尔/升时可检测到,令人惊讶的是,其浓度仅比典型的实验室台面规模反应低1000倍。通过将单个单体插入反应产生的信号与相邻催化剂的聚合物生长信号叠加,可以确定控制单周转事件的动力学状态。