Dynamic Covalent Chemistry for Synthesis and Co‐conformational Control of Mechanically Interlocked Molecules

Abstract

Mechanically interlocked molecules have found extensive applications in areas all across the physical sciences, from materials to catalysis and sensing. However, introducing mechanical bonds and entanglements at the molecular level is still a significant challenge due to the inherent restriction in entropy needed to preorganize strands before interlocking. Over the last decade, dynamic covalent chemistry has emerged as one of the most efficient methods of forming rotaxanes, catenanes and molecular knots. By using reversible bonds such as imines, disulfides and boronate esters, one can use the inherent error‐correction in these linkages to form interlocked architectures with high fidelity and often in excellent yields. This review reports on recent advances in the use of dynamic covalent chemistry to make mechanically interlocked molecules, systematically surveying clipping, capping and templating approaches with dynamic bonds. Furthermore, it is also discussed how dynamic bonds can be used to control motion, co‐conformational expression and catalytic activity in mechanically interlocked molecular machinery.

Polyrotaxane‐Based Functional Materials Enabled by Molecular Mobility and Conformational Transition†

“…Nowadays, most of the existing reviews related to rotaxanes and polyrotaxanes focus on the precise synthesis of mechanically interlocked molecules and the control of microscopic molecular shuttles to extend the scope of molecular machines. [ 36‐43 ] In terms of functional materials, the relationship between the fascinating pulley effect and high mechanical performance should be emphasized. Meanwhile, the diversity of material usage requirements in practical applications places high demands on the functional adaptability of slide‐ring structures.…”

Triphasic circularly polarized luminescence switch quantum simulation of a topologically chiral catenane

“…20–22 In this context, the emergence of a chiral topology in these entangled molecules offers the possibility to study the intricate interplay between the topological features and the circularly polarized luminescence (CPL). Notwithstanding the burgeoning of MIMs in many research articles, 23–26 their use as chiral emitters is still extremely limited: in fact, very few examples of CPL-active mechanically interlocked molecules are reported in the literature 27–30 and just one in this chemical elite is a catenane. 31 This unicum exploits the excimer nature of pyrene units to create a CPL multistate switch based on a mechanically interlaced platform as excellently described in a recent article by Yang et al 31 In this unexplored landscape, a theoretical treatment of a CPL-switch is still missing, and to the best of our knowledge, quantum simulation of chiral emission spectra generated by MIMs has never been reported.…”

Photoswitchable Cascades for Allosteric and Bidirectional Control over Covalent Bonds and Assemblies

“…By merging the strength of covalent bonds and the dynamic nature of supramolecular bonding forces, dynamic covalent chemistry (DCC) can lead to structural diversity and complexity, finding broad utility in the creation of molecular assemblies and functional materials . The control of reversible covalent systems via noninvasive light stimuli offers the advantage of driving the processes out-of-equilibrium .…”