20.500.12556/RUL-153058 Thermodynamics of the ion association of potassium cobalt(III) bis(1,2-dicarbollide) in acetonitrile, methanol and dimethyl sulfoxide 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. potassium cobalt(III) bis(1 2-dicarbollide) acetonitrile methanol dimethyl sulfoxide ion association thermodynamics termodinamika asociacija ionov acetonitril metanol dimetil sulfoksid true false true Angleški jezik Slovenski jezik Članek v reviji 2023-12-15 12:12:57 2023-12-15 12:12:58 2023-12-16 03:49:05 0000-00-00 00:00:00 2023 0 0 7 str. pt. A, art. 123234 Vol. 391 1 Dec. 2023 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 544.3 0167-7322 10.1016/j.molliq.2023.123234 168557827 1-s2.0-S0167732223020408-main.pdf 1-s2.0-S0167732223020408-main.pdf 1 002DD9D36723E7F57333B7EF20AA98C0 fdfb71dd33210d2b661042b9dd68352ad3771b8f85b254b12eb7d3b23b273582 22697373-9b3b-11ee-bebf-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=178855 https://www.sciencedirect.com/science/article/pii/S0167732223020408 1 e7581531-9b3a-11ee-bebf-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=178854 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0