Template Directed Syntheses of Electrochemically Active [2]Rotaxanes: Anion Binding and Redox Studies

A heteroditopic macrocycle, PhenMC, composed of phenanthroline ester, aromatic spacer and oxy ether moieties is explored to synthesize two new rotaxanes, RTXN1 and RTXN2 by employing different templating strategies, active metal templation and donor‐acceptor interaction respectively. In this regard, Cu(I) mediated azide‐alkyne cycloaddition reaction is adopted to achieve RTXN1 in case of active metal templation. On the other hand, a new 1 : 1 threaded complex, PRT1 (pseudorotaxane) is synthesized via π‐π stacking interaction between viologen moiety containing alkyne terminated axle and PhenMC toward the development of RTXN2 by appropriately stoppering the pseudorotaxane. All the synthesized compounds are well characterized by several methods such as ESI‐MS, ITC, UV‐Vis, 1D and 2D NMR spectroscopy, wherever applicable. Furthermore, RTXN1 has been explored toward inorganic anion binding studies by NMR titration and electrochemical methods. Subsequently, redox behavior of RTXN2 with multiple redox centers has also been described by cyclic voltammetry and UV‐Vis spectroscopic studies. One way or another: Utilization of two different templation strategies toward the syntheses of two rotaxane molecules with a heteroditopic macrocycle along with the investigations of electrochemical anion binding as well as redox properties.