Atomistic Simulations of COSAN: Amphiphiles without a Head‐and‐Tail Design Display “Head and Tail” Surfactant Behavior
Cobaltabisdicarbollide (COSAN) anions have an unexpectedly rich self-assembly behavior, being able to lead to vesicles and micelles without having a classical surfactant molecular architecture. New terms such as theta-shaped amphiphile, stealth amphiphile or intrinsic amphiphile have been coined to...
| Autores: | , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2020 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/230368 |
| Acceso en línea: | http://hdl.handle.net/10261/230368 |
| Access Level: | acceso abierto |
| Palabra clave: | COSAN Molecular dynamics simulations Nano-ions Self-assembly |
| Sumario: | Cobaltabisdicarbollide (COSAN) anions have an unexpectedly rich self-assembly behavior, being able to lead to vesicles and micelles without having a classical surfactant molecular architecture. New terms such as theta-shaped amphiphile, stealth amphiphile or intrinsic amphiphile have been coined to describe this molecule and new driving forces such as the “chaotropic effect” were invoked to understand its novel features. A key aspect in these interpretations of COSAN behavior is the assumption that the most stable form of these ions is the transoid rotamer which lacks a “hydrophilic head” and a “hydrophobic tail”. Using implicit solvent DFT calculations here we show that in water, the cisoid rotamer (which has a polar and an apolar region) is the most stable form of COSAN. Our MD simulations in water show that this cisoid rotamer has a well-defined hydrophilic polar “head” and a hydrophobic apolar “tail”. In addition, our simulations show that the properties of this rotamer in water (interfacial affinity, micellization) match with those expected for a classical surfactant. Therefore, we conclude that the experimental results for the COSAN ions can be now understood in terms of its amphiphilic molecular architecture. |
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