Proton Affinity and Conformational Integrity of a 24-Atom Triazine Macrocycle across Physiologically Relevant pH.

ABSTRACT: For 24-atom triazine macrocycles, protonation of the heterocycle leads to a rigid, folded structure presenting a network of hydrogen bonds. These molecules derive from dynamic covalent chemistry wherein triazine monomers bearing a protected hydrazine group and acetal tethered by the amino acid dimerize quantitatively in an acidic solution. Here, lysine is used, and the product is a tetracation. The primary amines of the lysine side chains do not interfere with quantitative yields of the desired bis(hydrazone) at concentrations of 5-125 mg/mL. Mathematical modeling of data derived from titration experiments of the macrocycle reveals that the pK_a values of the protonated triazines are 5.6 and 6.7. Changes in chemical shifts of resonances in the ¹H NMR spectra cor

SUBMITTER: Menke AJ 

PROVIDER: S-EPMC11512517 | biostudies-literature | 2024 Feb

REPOSITORIES: biostudies-literature