We believe this work will serve as important initial steps toward a controlled synthesis of CNTs.”
“Over the last selleck compound two decades, researchers have focused on the synthesis and development of mechanically interlocked molecules Inhibitors,Modulators,Libraries (MIMs). The intramolecular motion of mechanical bonds and the ability to induce this effect with the choice of the proper external stimuli has prompted the development of macromolecular systems that possess the ability to “”perform work”" at the molecular level. Currently, researchers are working to incorporate interlocked species into complex structural systems, such as molecular frameworks and nanoparticles, and to create ever more elegant noncovalent architectures. This effort provides an incentive to generate new building blocks for the construction of MIMs.

In this Account, we describe progress in the development of a new cationic building block inspired by the ‘blue box”" of Stoddart and collaborators.

The blue box (cylcobis(paraquat-p-phenylene) or CBPQT(4+)) is a tetracationic, electron-deficient macrocycle widely recognized Inhibitors,Modulators,Libraries for its role in the construction of MIMs. This venerable receptor displays a high affinity for a Inhibitors,Modulators,Libraries variety of pi-donor guests, and researchers have used them to construct a wide range of molecular and supramolecular structures, including rotaxanes, catenanes, pseudorotaxanes, polypseudorotaxanes, pseudo[n]polyrotaxanes, and electrochemically switchable molecules. To date, several synthetic analogues of the basic CBPQT(4+) structure have been reported, including systems containing biphenylene linkers and chiral tetracationic cyclophanes.

However, researchers have not yet fully generalized the promise of the blue box.

In Inhibitors,Modulators,Libraries this Account, we chronicle the development of a larger, more flexible tetracationic macrocycle, referred to as the “”Texas-sized”" molecular box. To highlight its relatively Drug_discovery increased size and to distinguish it from CBPQT(4+), we have chosen to color this new receptor burnt orange. The Texas-sized box (cyclo[2](2,6-di(1H-imidazol-1-yl)pyridine)[2](1,4-dimethylenebenzene), 1(4+)center dot 4PF(6)(-) acts as a dynamic molecular receptor that displays an ability to adjust its shape and conformation to accommodate anionic guests of different size and charge within its central core. The use of different guests can favor different binding modes and promote the formation of different macromolecular aggregates.

Furthermore, the proper selection obviously of the guest allows for the “”turning on”" or “”turning off”" of molecular threading and can be used to produce new kinds of threaded species. This dynamic behavior is a special feature of the Texas-sized molecular box, as is its ability to stabilize a range of polypseudorotaxanes, rotaxane-containing metal-organic frameworks (MORFs), and rotaxane-based supramolecular organic frameworks (RSOFs).