Potential application of metallacarboranes as an internal reference: an electrochemical comparative study to ferrocene

Ferrocene and its derivatives have been extensively used as an internal reference in electrochemical processes. Yet, they possess limitations such as solvent restrictions that require chemical modifications. In this regard, we have studied the use of metallacarboranes [3,3'-M(1,2-C2B9H11)2]- (M = Co, Fe) as general internal reference systems and have proven their suitability by thoroughly investigating their electrochemical properties in both aqueous and organic electrolytes without any derivatization.This work was funded by the Spanish Ministry of Science, through the ‘‘Severo Ochoa’’ Programme for Centres of Excellence in R&D (CEX2019-000917-S) as well as the Ministerio de Economia y Competitividad (PID2019-106832RB-I00), (PID2020- 116728RB-I00, CTQ2015-71955-RED ELECTROBIONET) and Generalitat de Catalunya (2017SGR1720) are appreciated. J. A. M. Xavier acknowledges DOC-FAM programme under the Marie Sklodowska-Curie grant agreement no. 754397 and is enrolled in the PhD programme in UAB. Support from the Community of Madrid (TRANSNANOAVANSENS S2018/NMT-4349), is acknowledged.With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S).Peer reviewe