Prakasam Thirumurugan, Bilbeisi Rana A, El-Khoury Roberto, Charbonnière Loïc J, Elhabiri Mourad, Esposito Gennaro, Olsen John-Carl, Trabolsi Ali
New York University Abu Dhabi (NYUAD), Experimental Research Building, Building C1, Saadiyat Island, Abu Dhabi, United Arab Emirates.
American University of Beirut, Department of Civil and Environmental Engineering (CEE), Faculty of Engineering and Architecture (FEA), Beirut, Lebanon.
Dalton Trans. 2017 Dec 21;46(47):16474-16479. doi: 10.1039/c7dt03582a. Epub 2017 Nov 17.
Topological transformation of a zinc-templated trefoil knot, Zn-TK, into a zinc-templated [2]catenane, Zn-[2]C, was studied. The net reaction 2 Zn-TK→3 Zn-[2]C was accomplished in 89% yield by heating a solution of Zn-TK in DO. Kinetic investigation by H NMR spectroscopy and high resolution mass spectrometry revealed that the mechanism is complex, involving a large pool of intermediates that form after imine bond cleavage. Bromide ions, which can occupy the central cavity of Zn-TK, inhibited the reaction. Two similar transformations were also studied, one of a cadmium-containing trefoil knot, Cd-TK, into a cadmium-containing catenane, Cd-[2]C, and the other of Cd-TK into Zn-[2]C. The latter transformation could be achieved in one step at high temperature or in two steps via transmetallation to form Zn-TK at room temperature followed by topological conversion of Zn-TK to Zn-[2]C at high temperature.
研究了锌模板三叶结（Zn-TK）向锌模板[2]索烃（Zn-[2]C）的拓扑转化。通过加热Zn-TK在DO中的溶液，以89%的产率完成了净反应2Zn-TK→3Zn-[2]C。通过1H NMR光谱和高分辨率质谱进行的动力学研究表明，该机制很复杂，涉及亚胺键断裂后形成的大量中间体。可占据Zn-TK中心腔的溴离子抑制了该反应。还研究了另外两个类似的转化，一个是含镉三叶结（Cd-TK）向含镉索烃（Cd-[2]C）的转化，另一个是Cd-TK向Zn-[2]C的转化。后一种转化可以在高温下一步完成，或者通过在室温下进行金属转移形成Zn-TK，然后在高温下将Zn-TK进行拓扑转化为Zn-[2]C分两步完成。
