Mechanically Interlocked Chiral Self‐Templated [2]Catenanes from 2,6‐Bis(1,2,3‐triazol‐4‐yl)pyridine (btp) Ligands

Abstract

We report the efficient self‐templated formation of optically active 2,6‐bis(1,2,3‐triazol‐4‐yl)pyridine (btp) derived homocircuit [2]catenane enantiomers. This represents the first example of the enantiopure formation of chiral btp homocircuit [2]catenanes from starting materials consisting of a classical chiral element; X‐ray diffraction crystallography enabled the structural characterization of the [2]catenane. The self‐assembly reaction was monitored closely in solution facilitating the characterization of the pseudo‐rotaxane reaction intermediate prior to mechanically interlocking the pre‐organised system via ring‐closing metathesis.

Luminescent (metallo-supramolecular) cross-linked lanthanide hydrogels from a btp (2,3-bis(1,2,3-triazol-4-yl)picolinamide) monomer give rise to strong Tb(iii) and Eu(iii) centred emissions

“…Previous btp ligands have been most commonly reported in the anti-anti conformation, but in the presence of a cation such as a metal ion or a proton, the triazoles can adopt the syn-syn conformation. 23,35,36 In this case, the RNH 3 + of one ligand molecule, and the triazole N14 and N31 nitrogen atoms of the adjacent ligand molecule, form a hydrogen bonding interaction with an NÁ Á ÁN distance of 2.998( 6) and 2.885(6) Å, respectively, which causes the triazoles to adopt the syn-syn conformation.…”

Generating water/MeOH-soluble and luminescent polymers by grafting 2,6-bis(1,2,3-triazol-4-yl)pyridine (btp) ligands onto a poly(ethylene-alt-maleic anhydride) polymer and cross-linking with terbium(iii)

“…This was recently demonstrated by our research group where we exploited the self-templating features of both chiral as well as achiral olefin btp precursors to synthesise homocircuit [2]catenanes and pseudo-rotaxanes using ring closing metathesis (RCM) reactions. 20,21 We have also been interested in the use of btp complexes in the formation of responsive polymers, and demonstrated that such complexes can be incorporated into HEMA polymers. 22 However, since these complexes are doped non-covalently into the polymer hosts, they are prone to leaching from the material during solvent swelling processes.…”

Supramolecular chemistry of two new bis(1,2,3-triazolyl)pyridine macrocycles: metal complexation, self-assembly and anion binding

“…Interestingly, Byrne and Gunnlaugsson have also demonstrated that the 2,6-btp motif can self-recognise through C-H⋯N hydrogen bonding, and have used this recognition to template the formation of catenanes. [38][39][40] We initially targeted macrocycles 34,35 containing the 2,6-btp motif as a possible route to catenanes containing both metal and anion binding motifs with the hope that these would be suitable for both anion and metal binding, and potentially also ion pair recognition 41,42 (Fig. 2).…”

“…Interestingly, Byrne and Gunnlaugsson have also demonstrated that the 2,6- btp motif can self-recognise through C–H⋯N hydrogen bonding, and have used this recognition to template the formation of catenanes. 38–40…”