Nanohoop Rotaxane Design to Enhance Selectivity of Reaction Based Probes: A Proof of Principle Study

Abstract

<p>A novel fluorescent probe design based on the interlocking of a reactive thread in a rigid nanohoop fluorophore is reported. This rotaxane design leads to size-selective sensing of thiolates in organic solution. More broadly, the work suggests the promise of mechanical interlocking to enhance the selectivity of reaction-based probes.</p>

Preprogrammed assembly of supramolecular polymer networks via the controlled disassembly of a metastable rotaxane

“…The purity and interlocked nature of [3]MSR were assessed by 1D and 2D NMR spectroscopy (Supplementary Figs. [21][22][23][24][25][26][27]. The 1 H NMR spectrum showed resonances + NH 2 and e visibly shifted (e.g., Δδ e = 0.25 ppm) with respect to those of free 1 4+ (Fig.…”

“…The assembly of MIMs has been of particular interest in recent years 15 (new syntheses 16 and emerging host and guest elements 17 ), which is in stark contrast to the few studies that have explored their disassembly. These examples include the delivery of small molecules to a medium [18][19][20][21] and the degradation of crosslinked polymers using metastable rotaxanes [22][23][24] .…”

Nanohoop Rotaxane Design to Enhance the Selectivity of Reaction-Based Probes: A Proof-of-Principle Study

“…The smallest species in this family is hydrogen sulfide (H 2 S), one of three currently recognized gasotransmitters . H 2 S is involved in a wide variety of regulatory processes, and the diverse roles in human physiology make it an important target of research. − Selective reaction-based probes that rely on H 2 S/HS – nucleophilicity are often challenging to design because other biologically relevant nucleophilic thiols are present in much greater concentrations (low nM for H 2 S vs low mM concentrations for glutathione). ,− Herein, we report a novel turn-on fluorescent nanohoop [2]­rotaxane for selective sensing of HS – in organic solution based on the well-documented S N Ar reaction of thiolates with 2,4-dinitrophenyl (DNP) ethers. − We provide a proof-of-principle demonstration that encapsulation of a DNP ether thread within a nanohoop via mechanical interlocking effectively couples the benefits of a reactive probe with a sterically tailored active site, enhancing the selectivity of the probe.…”