20.500.12556/RUL-167754 Aggregation of metallacarborane mixtures in aqueous solutions iron bis(1,2-dicarbollide) as paramagnetic probe in aggregates of diamagnetic cobalt bis(1,2-dicarbollide) Metallacarboranes are surface active inorganic boron cluster compounds, and they exhibit solution behavior comparable to organic amphiphiles. We compared the aggregation abilities of two anionic metallacarborane clusters, cobalt(III) bis(1,2-dicarbollide), COSAN, and iron(III) bis(1,2-dicarbollide), FESAN, in aqueous solutions using of NMR spectroscopy, isothermal titration calorimetry, tensiometry, and all-atom molecular dynamics simulations. Leveraging strong paramagnetic effect of FESAN, we used it as a probe in COSAN/FESAN mixed aggregates in order to understand their structure and dynamics. Calculations confirmed that both COSAN and FESAN clusters have the same propensity to form small aggregates with bound sodium counterions. It was confirmed that both COSAN and FESAN are moderately surface active, and the surface activity is monotonically decreasing even above the critical aggregation concentration, CAC. All the techniques confirmed that the aggregation process as well as the structure of the aggregates of COSAN, FESAN and their mixtures are practically the same. Consequently, FESAN is an effective paramagnetic probe. The thorough paramagnetic NMR study revealed that the dynamics of the aggregates in respect to clusters exchange is very fast. The paramagnetic induced shifts, PISs, did not provide any conclusive picture of the aggregate structure because of the rapid averaging. However, the investigation of the paramagnetic relaxation enhancements, PREs, clearly showed that the CH1,2 and CH1′,2′ groups of the metallacarborane clusters in the cisoid conformation are preferentially oriented inwards the aggregates, and the rotation and dynamics of the clusters are restricted. metallacarboranes aggregation paramagnetic NMR surface activity mixed aggregates metalokarborani agregacija paramagnetna NMR površinska aktivnost mešani agregati true false true Angleški jezik Slovenski jezik Članek v reviji 2025-03-10 14:25:25 2025-03-10 14:25:26 2025-03-14 10:21:56 0000-00-00 00:00:00 2025 0 0 12 str. Vol. 425, art.127232 1 May 2025 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 544.77.052.2 0167-7322 10.1016/j.molliq.2025.127232 227958787 1-s2.0-S016773222500399X-main.pdf 1-s2.0-S016773222500399X-main.pdf 1 6615A08A77D6759CE7664D5B2C8BF4D3 69483abe089e73603079992f5f90b1870f4a0ce1ff9498cf4edeee5023469ba8 3792ef12-fdb3-11ef-b232-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=200502 https://www.sciencedirect.com/science/article/pii/S016773222500399X 1 29f80417-fdb2-11ef-b232-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=200501 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0