Sandwiched: The cobaltabisdicarbollide (mono-)anion ([3,3′-Co(1,2-C₂B₉H₁₁)₂]⁻, COSAN⁻) forms monolayer vesicles at low concentrations in water (see picture). An increase in concentration leads to a Coulomb explosion of the closely packed vesicles into small micelles, which results in the coexistence of both aggregation states at higher concentrations.

This tutorial review will deal with the study of metallacarboranes and their interactions with other molecules from a theoretical point of view. This contribution is devoted to guide experimental chemists through calculations that some years ago were reserved to theoretical specialists. The widespread availability of fast computers enables nowadays studies of complex compounds (e.g. metallacarboranes) from different perspectives including simulation of NMR, infrared or Raman spectra and calculation of other properties such as atomic charges or inter-/intramolecular interactions. The insights gained on the basis of theoretical calculations are crucial for either finding novel or improving existing applications of metallacarboranes. For example, in the case of enzyme inhibitors, the interactions of the metallacarboranes with the surrounding protein and how the interaction affects the efficiency are difficult problems to study experimentally. The use of theoretical tools can provide a detailed understanding of the physico-chemical basis of the interactions and thus offers a chance to control the overall process.

The fabrication of biomimetic catalysts as substituents for enzymes is of critical interest in the field due to the problems associated with the extraction, purification, and storage of enzymes in sensing applications. Of these mimetics, hemin/coordination polymer‐based nanocomposites, mainly hemin/metal–organic frameworks (MOF), have been developed for various biosensing applications because of the unique properties of each component, while trying to mimic the normal biological functions of heme within the protein milieu of enzymes. This critical review first discusses the different catalytic functions of heme in the body in the form of enzyme/protein structures. The properties of hemin dimerization are then elucidated with the supposed models of hemin oxidation. After that, the progress in the fabrication of hemin/MOF nanocomposites for the sensing of diverse biological molecules is discussed. Finally, the challenges in developing this type of composites are examined as well as possible proposals for future directions to enhance the sensing performance in this field further.

[3,3′-Co(1,2-C₂B₉H₁₁)₂]⁻, [1]⁻, and its chloroderivatives have been described as displaying surfactant/aggregation properties. We have studied their behaviour as electrolytes in the water electrolysis process. The electrolysis experiments support the surfactant behaviour of these compounds. These conclusions have been drawn on the grounds of the intensity/voltage (I/V) curves of water splitting into H₂ and O₂ of aqueous solutions in which the electrolytes have been tested at the same concentration. The I/V curves have permitted us to map and group the different electrolytes studied in this work. Three differentiated zones have been observed: one for true electrolytes, NO₃ ⁻ and ClO₄ ⁻; a second one for intermediate electrolytes, BF₄ ⁻ and p-toluenesulfonate (PTS); and a third having the surfactant dodecylbenzenesulfonate (DBS), [1]⁻ and its chloroderivatives. The incorporation into the study of the chloroderivatives of [1]⁻ has allowed us to correlate molecular structure features with aqueous performance. The studied chloroderivatives perform better as electrolytes in accordance with the descending order of available B–H groups. This comes from the higher capacity to generate B–H⋯H–C_c dihydrogen bonds in the non- or less-halogenated molecules, considered one of the main reasons for the generation of the aggregates. In order to generate B–H⋯H–C_c dihydrogen bonds the H–C_c from the carborane cluster is needed. [B₁₂H₁₂]²⁻ was chosen to prove the hypothesis as it has B–H units but lacks H–C_c units. Consequently, it should not produce self-assembling motifs, as is the case. [B₁₂H₁₂]²⁻ has an aqueous behaviour similar to SO₄ ²⁻.