Thermodynamics of the ion association of potassium cobalt(III) bis(1,2-dicarbollide) in acetonitrile, methanol and dimethyl sulfoxide

Šarac, Bojan (avtor), Ogrin, Peter (avtor), Medoš, Žiga (avtor), Urbič, Tomaž (avtor), Matějíček, Pavel (avtor), Bešter-Rogač, Marija (avtor)

The molar conductivities, Λ, of dilute solutions of potassium cobalt(III) bis(1,2-dicarbollide) (K[COSAN]) in methanol (MeOH), acetonitrile (MeCN) and dimethyl sulfoxide (DMSO) were determined at different temperature ranges. The data were analysed in the frame of Barthel’s low-concentration chemical model (lcCM) to obtain the limiting molar conductivities, Λ$^∞$, and standard association constants, K$^o_A$, of K[COSAN]. To confirm the ion association of oppositely charged ions K$^+$ and [COSAN]$^–$, molecular dynamics (MD) simulations were performed, in which the values of K$^o_A$ from the potential of the mean force between the pair of particles (ions) were determined. From temperature dependence of K$^o_A$, the thermodynamic parameters for ion association, namely standard free enthalpy ΔG$^o_A$, enthalpy ΔH$^o_A$, and entropy ΔS$^o_A$, were estimated. The dilution enthalpies of concentrated solutions of K[COSAN] in organic solvents were also determined by using isothermal titration calorimetry (ITC). Our experimental results show that K$^+$ and [COSAN]$^–$ ions form ion pairs in all the investigated solvents. Ion association is most pronounced in MeOH and MeCN and the least expressed in DMSO, the process is endothermic and is accompanied by an increase in entropy. The agreement between the calculated values of K$^o_A$ and the thermodynamic parameters obtained by conductivity and MD simulations follow the same trend.

• Jezik: Angleški jezik
• Ključne besede: potassium cobalt(III) bis(1, 2-dicarbollide), acetonitrile, methanol, dimethyl sulfoxide, ion association, thermodynamics
• Vrsta gradiva: Članek v reviji
• Tipologija: 1.01 - Izvirni znanstveni članek
• Organizacija: FKKT - Fakulteta za kemijo in kemijsko tehnologijo
• Status publikacije: Objavljeno
• Različica publikacije: Objavljena publikacija
• Leto izida: 2023
• Št. strani: 7 str.
• Številčenje: Vol. 391, pt. A, art. 123234
• PID: 20.500.12556/RUL-153058
• UDK: 544.3
• ISSN pri članku: 0167-7322
• DOI: 10.1016/j.molliq.2023.123234
• COBISS.SI-ID: 168557827
• Datum objave v RUL: 15.12.2023

Gradivo je del revije

• Naslov: Journal of molecular liquids
• Skrajšan naslov: J. mol. liq.
• Založnik: Elsevier
• ISSN: 0167-7322
• COBISS.SI-ID: 15382277

Licence

• Licenca: CC BY-NC-ND 4.0, Creative Commons Priznanje avtorstva-Nekomercialno-Brez predelav 4.0 Mednarodna
• Povezava: http://creativecommons.org/licenses/by-nc-nd/4.0/deed.sl
• Opis: Najbolj omejujoča licenca Creative Commons. Uporabniki lahko prenesejo in delijo delo v nekomercialne namene in ga ne smejo uporabiti za nobene druge namene.

Sekundarni jezik

• Jezik: Slovenski jezik
• Ključne besede: termodinamika, asociacija ionov, acetonitril, metanol, dimetil sulfoksid