Naslov
THE THERMODYNAMICS OF HYDROPHOBICALY DRIVEN INCLUSION; β-CYCLODEXTRIN VS. CUCURBIT[7]URIL
(THE THERMODYNAMICS OF HYDROPHOBICALY DRIVEN INCLUSION; β-CYCLODEXTRIN VS. CUCURBIT[7]URIL)

Autori
Usenik, Andrea ; Leko, Katarina ; Petrović Peroković, Vesna ; Car, Željka ; Ribić, Rosana ; Pičuljan, Katarina ; Hanževački, Marko ; Požar, Josip

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Skup
Magnetic Moments in Central Europe 2022 (MMCE 2022)

Mjesto i datum
Primošten, Hrvatska, 01.06.2022. - 04.06.2022

Vrsta sudjelovanja
Poster

Vrsta recenzije
Domaća recenzija

Ključne riječi
Hydrophobic effect ; solvophobic effect ; inclusion complex ; complexation thermodynamics ; cyclodextrins ; cucurbit[7]uril ; mannoconjugates

Sažetak
Cyclodextrins and cucurbiturils are very good receptors of hydrophobic species in water. The product stability (logK > 10 for complexes involving neutral guests and cucurbiturils were reported) is a consequence of strongly exothermic association, rationalized by non-classical hydrophobic effect (release of energetically rich cavity water). However, our recent study of the adamantyl-based guest inclusion within β-cyclodextrin (β-CD) revealed an almost complete compensation of ΔrH°(T) and –TΔrS°(T) contributions to logK temperature dependence. The results could be explained by the Frank-Evans model of adamantane hydration at lower (classical hydrophobic effect) and gradual “iceberg melting” at higher temperatures. We have therefore decided to study the complexation of both (poly)cyclic and linear aliphatic compounds with cucurbit[7]uril (CB7) and β-CD in a wide temperature range, both experimentally (ITC, ROESY NMR spectroscopy) and computationally (classical, solvent-explicit MD simulations). The investigated guests were chosen with the aim of supressing all thermodynamic contributions to hosting apart those associated with the hydrophobic effect. The study provided missing pieces to a jigsaw puzzle explaining the thermodynamic contributions to standard complexation Gibbs energies, as well as insights into hydration of guest and host cavities. Apart from that, intriguing differences concerning the enthalpic and entropic effect of CB7 and β-CD cavity dehydration were revealed.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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