875440-61-2Relevant articles and documents
A taco complex derived from a bis-crown ether capable of executing molecular logic operation through reversible complexation
Mandal, Amal Kumar,Das, Priyadip,Mahato, Prasenjit,Acharya, Suhash,Das, Amitava
scheme or table, p. 6789 - 6800 (2012/09/25)
As learned from natural systems, self-assembly and self-sorting help in interconnecting different molecular logic gates and thus achieve high-level logic functions. In this context, demonstration of important logic operations using changes in optical resp
Operating molecular elevators
Badjic, Jovica D.,Ronconi, Celia M.,Stoddart, J. Fraser,Balzani, Vincenzo,Silvi, Serena,Credi, Alberto
, p. 1489 - 1499 (2007/10/03)
Inspired by the concept of multivalency in living systems, two mechanically interlocked molecules have been conceived that incorporate not once or twice but thrice the features of a pH-switchable [2]rotaxane with two orthogonal recognition sites for dibenzo[24]crown-8 (DB24C8), and 2,3-dinaphtho[24]crown-8 (DN24C8)-one a dialkylammonium ion (CH2NH2 +CH2) and the other a bipyridinium dication (BIPY 2+). Whereas at low pH, the CH2NH2 +CH2 sites bind the DB24C8/DN24C8 macrocycles preferentially, at high pH, deprotonation occurs with loss of hydrogen bonding and the macrocycles will move to the BIPY2+ sites, where they can acquire some stabilizing [π-π] stacking interactions. Such mechanically interlocked molecules have been assembled from a trifurcated rig-like component wherein the dumbbell-like components of three [2]rotaxanes have one of their ends fused onto alternate positions (1,3,5) around a benzenoid core. The rig is mechanically interlocked by a platform based on a tritopic receptor, wherein either three benzo[24]crown-8 or three 2,3-naphtho[24]crown-8 macrocycles are fused onto a hexaoxatriphenylene core. The synthesis of these molecular elevators involves 1:1 complexation, followed by stoppering, i.e., feet are added to the rig. 1H NMR spectroscopy and cyclic voltammetry, aided and abetted by absorption spectroscopy, have been employed to unravel the details of the mechanism by which the rig and platform components move on the alternate addition of base and acid. For each molecular elevator, the platform operates by taking three distinct steps associated with each of the three deprotonation/reprotonation processes. Thus, molecular elevators are more reminiscent of a legged animal than they are of passengers on freight elevators.
