A halogen- and hydrogen-bonding [2]catenane for anion recognition and sensing

Abstract

A mixed halogen- and hydrogen-bonding hetero-[2]catenane has been synthesised via anion templation and demonstrated to bind and sense oxoanions.

Formation of Self‐Templated 2,6‐Bis(1,2,3‐triazol‐4‐yl)pyridine [2]Catenanes by Triazolyl Hydrogen Bonding: Selective Anion Hosts for Phosphate

“…Similarly, whereas the anion‐templated synthesis of interlocked structures has been elegantly demonstrated, most notably by Beer and co‐workers, the recognition and sensing of anions by the use of catenanes as “anion hosts” has been relatively unexplored. Most examples to date show selectivity for halide ions through halogen‐ or hydrogen‐bonding interactions within the catenane cavity ,. From the crystal structure of 3 (Figure a), it can be seen that the btp – btp units are orientated in a manner that gives rise to a highly preorganized hydrogen‐bonding environment, which can be described as being close to a “tetrahedral” arrangement.…”

Exploiting the mechanical bond for molecular recognition and sensing of charged species

“…16). 63 Addition of various anions, particularly acetate and dihydrogen phosphate, to a solution of 30•PF6 in acetonitrile caused an increase of the naphthalene monomer emission bands and the concomitant decrease in intensity of an excimer emission band. The observed sensory response was attributed to the increased rigidity reducing the number of available vibrational and rotational non-radiative decay pathways upon anion binding.…”

1,2,3-Triazolium macrocycles in supramolecular chemistry

“…Soon after, a mixed halogen and hydrogen bonding hetero[2]catenane 6 (Fig. 6) was successfully synthesized by the same group via an anion templated Grubbs’ II-catalyzed RCM clipping mechanical bond forming methodology [48]. The 1 H NMR spectroscopy in CDCl 3 (293 K, 500 MHz) and the fluorescence titration experiments which were done in acetonitrile have demonstrated that the synthesized 1,2,3-triazolium macrocycle 6 was able to bind and sense several anions but the highest affinity of this receptor was for acetate ( K a = 1.5 × 10 5 M −1 ) and dihydrogen phosphate ( K a = 4.5 × 10 4 M −1 ).…”