The flowering of Mechanically Interlocked Molecules: Novel approaches to the synthesis of rotaxanes and catenanes

Abstract

Since the emergence of mechanical bonds, considerable research efforts have been devoted to the construction of mechanically interlocked molecules (MIMs), including rotaxanes, catenanes, and molecular knots, due to their mechanically bonded components that can undergo molecular motions and create distinguishing features. They have demonstrated valuable functions in many areas of science such as polymer and materials science, nanotechnology and medicine. Furthermore, since MIMs are magnificently suited for constructing artificial molecular machines (AMMs), immense attention has currently been attracted to this area. Recent elaborate synthetic strategies accompanied by novel analytical characterization techniques have led to a number of elegant catenanes and rotaxanes for various applications. The challenge now is to make more and more sophisticated compounds and novel architectures in higher yields. Here, we provide a “state-of-the-art” overview of research involving advances in MIMs synthesis, the newest architectures and their applications since the announcement of the 2016 Nobel Prize in Chemistry and the increasing interest in research into this field. The present review is designed to cover most of the recent studies in the synthesis of catenanes and rotaxanes depicting novel synthetic procedures to generate unprecedented MIMs with diverse properties that have not been mentioned en bloc in any reviews before.