Abstract:
A novel supramolecular complex C44H71Cl2N26O22 (CB[6]@Pipa⋅2HCl) of the “host-guest” type has been synthesized. It is based on cucurbit[6]uril (CB[6]) with dihydrochloride 1,4-bis(2-hydroxyethyl)piperazine
(Pipa⋅2HCl) localized within the portals of the macrocycle. Based on 1H NMR and X-ray crystallography, the
host–guest ratio in the complex under the specified conditions was determined to be 1:1. Further evidence of
complex formation was observed through IR spectroscopy, where a shift in the absorption band of carbonyl
vibrational frequencies of cucurbit[6]uril by 36 cm− 1 towards the longer wavelength region was detected in CB
[6]@Pipa⋅2HCl compared to the original CB[6]. TGA/DSC analysis results indicated an increase in thermal
stability by 55 ◦C for the obtained CB[6]@Pipa⋅2HCl complex compared to the initial 1,4-bis(2-hydroxyethyl)
piperazine dihydrochloride. The structure of the synthesized CB[6]@Pipa⋅2HCl complex was confirmed using
single-crystal XRD.
