Sensing anions on surfaces: tethering triazolium based anion receptors to polymer resins

Abstract

Herein we report the development of a new series of surface bound triazolium based anion sensors. Differences in the chemical reactivity and anion binding properties were observed; highlighting the need for good surface characterisation techniques such as HR MAS NMR.

Halogen bonding and chalcogen bonding mediated sensing

“…171,172 Interfacial XB or ChB optical sensors remain even more embryonic; the only example being the benzoselenadiazole bres developed by Che for uorescent gas sensing. 131 Clearly there is signicant untapped potential in further exploration of XB and ChB (sensing) materials, 182,183 particularly in thin lms and (interfacial) polymers [184][185][186] in electrochemical, optical and other sensing formats.…”

Surface‐Assembled Mechanically Interlocked Architectures

“…Similar surface attachment issues were noted by Mullen et al. with their surface‐attached triazolium‐based anion sensors on TentaGel resins . Whereas the alkylation of the triazole moiety proceeds smoothly in solution, it results in decomposition on the bead resins, and thus alternative synthetic strategies were needed to synthesise the target anion receptors.…”

“…However, attachment of interlocked architectures to swelling polymer supports (such as TentaGel polystyrene resins) allows the use of high‐resolution magic angle spinning (HR MAS) 1 H NMR spectroscopy to analyse the dynamic behaviour of molecules tethered to solid supports. This technique has been used more extensively to monitor biological protein or peptide synthesis and combinatorial chemistry, however spectra of more complex supramolecular systems tethered to solid supports have also been obtained …”

Attempted synthesis of a meta-metalated calix[4]arene

“…Another main contaminant was the dichloro( p -cymene)ruthenium(II) dimer, which we could not eliminate even after using sub-stoichiometric quantities in the reaction. Attempted purification via alumina flash chromatography returned material that was assigned as the triazolium chloride salt (i.e., Cl – salt of triazolium 12 ; based on chemical shifts in the 1 H and 13 C NMR that were consistent with a literature report [32]). This was presumably due to ruthenium undergoing a reductive elimination and the chloride remaining on the triazolium moiety.…”