Metallatranes (M = Si, Ge, Sn) have been studied intensively during 50 years and have many applications in various domains namely physics, biology, medicine and so on. However their electrochemical properties were poorly studied up to date. In the present work, new metallatranes have been synthesized and characterized using different approaches and techniques (organic synthesis, cyclic voltammetry, preparative electrolysis, EPR, spectroelectrochemistry, cyclic voltammetry coupled with EPR, NMR, GC-MS). Several novel structures of metallatranes have been obtained and validated by XRD. Electrochemical measurements show that the electrooxidation of metallatranes occurs via electrochemically reversible one-electron transfer resulting in the corresponding cation radicals (CRs), detected by cyclic voltammetry, UV-vis spectroscopy and real-time EPR spectroscopy. The spin delocalization in these paramagnetic species has been characterized and supported by DFT calculations. We focused on the electronic properties of metallatranes and on various bonding systems between pentacoordinated silicon and N atom including the substituents. We also considered the issue of non-coordinating, non-nucleophilic supporting salts for electrochemistry as they provide good ionic conductivity in the solvents of low polarity and allow carrying out voltammetry and EPR experiments on unstable electrogenerated electrophilic and radical species.
