Synergistic topological and supramolecular control of Diels-Alder reactivity based on a tunable self-complexing host-guest molecular switch.

Compartmentalization and binding-triggered conformational change regulate many metabolic processes in living matter. Here, we have synergistically combined these two biorelevant processes to tune the Diels-Alder (DA) reactivity of a synthetic self-complexing host-guest molecular switch CBPQT -Fu, consisting of an electron-rich furan unit covalently attached to the electron-deficient cyclobis(paraquat-p-phenylene) tetrachloride (CBPQT , 4Cl ) host. This design allows CBPQT -Fu to efficiently compartmentalize the furan ring inside its host cavity in water, thereby protecting it from the DA reaction with maleimide.

Chiral Quantum Metamaterial for Hypersensitive Biomolecule Detection.

Chiral biological and pharmaceutical molecules are analyzed with phenomena that monitor their very weak differential interaction with circularly polarized light. This inherent weakness results in detection levels for chiral molecules that are inferior, by at least six orders of magnitude, to the single molecule level achieved by state-of-the-art chirally insensitive spectroscopic measurements. Here, we show a phenomenon based on chiral quantum metamaterials (CQMs) that overcomes these intrinsic limits.

Supramolecular Competitive Host-Guest Interaction Induced Reversible Macromolecular Metamorphosis.

In this work, a rational strategy of competitive host-guest complexation between dioxynaphthalene (Naph) and tetrathiafulvalene (TTF) subunits as guests and cyclophane cyclobis(paraquat-p-phenylene) (CBPQT ) module as host is exploited to modify the macromolecular architecture, so-called supramolecular metamorphosis, in aqueous media. The architectures of the polymers can be reversibly transformed from a linear diblock copolymer AB to a linear AC block copolymer or from a linear block copolymer to a comb copolymer by redox switching. Interestingly, as TTF- and Naph-based complexes feature different characteristic colors, it offers a great opportunity to directly observe nanoscaled macromolecular metamorphosis of materials with the naked eye.

Elaboration of thermoresponsive supramolecular diblock copolymers in water from complementary CBPQT4+ and TTF end-functionalized polymers.

A well-defined poly(N-isopropyl acrylamide) 1 incorporating at one termini a cyclobis(paraquat-p-phenylene) (CBPQT(4+)) recognition unit is prepared via a RAFT polymerization followed by a copper-catalyzed azide-alkyne cycloaddition (CuAAC). (1)H NMR (1D, DOSY), UV-vis and ITC experiments reveal that polymer 1 is able of forming effective host-guest complexes with tetrathiafulvalene (TTF) end-functionalized polymers in water, thereby leading to the formation of non-covalently-linked double-hydrophilic block copolymers. The effect of the temperature on both the LCST phase transition of 1 and its complexes and on CBPQT(4+)/TTF host-guest interactions is investigated.

Surfactant-mediated control of CBPQT(4+)-dialkoxynaphthalene complexation.

The addition of the surfactant SDS to an aqueous solution containing 1·2 results in the disassembly of the latter via the simultaneous incorporation of 1 into a micelle and the precipitation of 2 by an anion exchange reaction.