Light‐Induced On/Off Switching of the Surfactant Character of the o ‐Cobaltabis(dicarbollide) Anion with No Covalent Bond Alteration

Cobaltabis(dicarbollide) anion ([o-COSAN]- ) is a well-known metallacarborane with multiple applications in a variety of fields. In aqueous solution, the cisoid rotamer is the most stable disposition in the ground state. The present work provides theoretical evidence on the possibility to photoinduce the rotation from the cisoid to the transoid rotamer, a conversion that can be reverted when the ground state is repopulated. The non-radiative decay mechanisms proposed in this work are coherent with the lack of fluorescence observed in 3D fluorescence mapping experiments performed on [o-COSAN]- and its derivatives. This phenomenon induced by light has the potential to destruct the vesicles and micelles cisoid [o-COSAN]- typically forms in aqueous solution, which could lead to promising applications, particularly in the field of nanomedicine.
This work was supported by the Generalitat Valenciana (GV, project GV/2020/226), Generalitat de Catalunya (2017 SGR 1720), and the Spanish Ministerio de Ciencia e Innovación (MICINN, projects CTQ2017-87054-C2-2–304-P and PID2019-106832RB-I00). A.M.A.A. is grateful to the Erasmus+ Programme of the European Comission for his Erasmus Mundus TCCM scholarship. A.F.-M. is grateful to the GV and the European Social Fund for the postdoctoral contract APOSTD/2019/149 and to the MICINN for the Juan de la Cierva contract IJC2019-039297-I. D.R.-S. is grateful to the MICINN for the “Ramón y Cajal” grant (RYC-2015–19234). “Severo Ochoa” Program for Centers of Excellence in R&D 234 (SEV-2015-0496) is appreciated. J. A. M. Xavier acknowledges DOC-FAM programme under the Marie Sklodowska-Curie grant agreement No. 754397 and is enrolled in the PhD program of the UAB. Computations have been conducted at the local QCEXVAL and the LluisVives and Tirant III clusters of the Servei d'Informàtica (University of Valencia). We thank Dr. Jordi Faraudo (ICMAB-CSIC) for the scientific discussions.
With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S).