Aggregation of metallacarborane mixtures in aqueous solutions : iron bis(1,2-dicarbollide) as paramagnetic probe in aggregates of diamagnetic cobalt bis(1,2-dicarbollide)

Matějíček, Pavel (avtor), Hleli, Belhssen (avtor), Medoš, Žiga (avtor), Tošner, Zdeněk (avtor), Ogrin, Peter (avtor), Urbič, Tomaž (avtor), Bešter-Rogač, Marija (avtor)

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.

• Jezik: Angleški jezik
• Ključne besede: metallacarboranes, aggregation, paramagnetic NMR, surface activity, mixed aggregates
• 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: 2025
• Št. strani: 12 str.
• Številčenje: Vol. 425, art.127232
• PID: 20.500.12556/RUL-167754
• UDK: 544.77.052.2
• ISSN pri članku: 0167-7322
• DOI: 10.1016/j.molliq.2025.127232
• COBISS.SI-ID: 227958787
• Datum objave v RUL: 10.03.2025

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 4.0, Creative Commons Priznanje avtorstva 4.0 Mednarodna
• Povezava: http://creativecommons.org/licenses/by/4.0/deed.sl
• Opis: To je standardna licenca Creative Commons, ki daje uporabnikom največ možnosti za nadaljnjo uporabo dela, pri čemer morajo navesti avtorja.

Sekundarni jezik

• Jezik: Slovenski jezik
• Ključne besede: metalokarborani, agregacija, paramagnetna NMR, površinska aktivnost, mešani agregati

Projekti

• Financer: Drugi - Drug financer ali več financerjev
• Program financ.: Czech Science Foundation
• Številka projekta: 21-20008K
• Akronim: LA CEUS

• Financer: ARRS - Agencija za raziskovalno dejavnost Republike Slovenije
• Številka projekta: N1-0186
• Naslov: Metalcarborani kot edinstveno izhodišče za pripravo funkcionalnih nanostrukturiranih in polimernih materialov