Naslov
Thermodynamics of Complexation of Alkali-Metal Cations by Fluorescent Phenanthridine-Based Calix[4]arene Derivatives

Autori
Tranfić Bakić, Marina ; Horvat, Gordan ; Požar, Josip ; Frkanec, Leo ; Tomišić, Vladislav

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

Izvornik
13th International Conference on Calixarenes (Calix 2015) : Book of Abstracts / - , 2015, SL11-SL11

Skup
13th International Conference on Calixarenes (Calix 2015)

Mjesto i datum
Giardini-Naxos, Italija, 05.07.2015. - 09.07.2015

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
calixarenes ; alkali-metal cations ; complexation ; thermodynamics ; fluorescence

Sažetak
Complexation of fluorescent calix[4]arene derivatives 1 and 2 with alkali-metal cations was studied at 25 °C in acetonitrile/dichloromethane and methanol/dichloromethane solvent mixtures (φ = 0.5) by means of fluorimetric, spectrophotometric, potentiometric, and microcalorimetric titrations as well as NMR spectroscopy. The stability constants of the corresponding complexes were determined, as were the enthalpies and entropies of the complexation reactions. The solvent effect on the equilibria of these reactions was particularly addressed. It was found that cation-binding affinity of ligand 1 with four phenathridine subunits was much higher than that of 2, with the complex stabilities in all cases being significantly lower in methanol/dichloromethane mixture compared to that in acetonitrile/dichloromethane. These findings could be explained by taking into account the determined thermodynamic complexation data, structural properties of the ligand and free and complexed cations, as well as the solvation abilities of the solvents examined. The conclusions made on the basis of the experimental results were supported by the molecular dynamics simulations of the systems studied. The applied integrated approach comprising several experimental and computational techniques has provided a rather detailed insight into the factors governing the complexation processes.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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