Electrochemistry and its analytics are essential in a variety of scientific and technological fields where properties related to reduction‐oxidation reactions, so‐called redox properties, are to be explored. While methodological standards for experiments are well established at room temperature, this is still untrue at sub‐zero/cryogenic temperatures, the conditions required for the survey of (ultra−)rapid processes and their intermediates. Problems due to “hand‐waving” temperature regulation/conditioning and common usage of pseudo‐reference electrodes renders cryo‐electrochemistry a great challenge. Herein, we describe a robust setup for performing reliable cryo‐electrochemical experiments down to −80 °C. It combines highly stable but flexible temperature conditioning with gas‐tight sealing of the electrochemical cell setup. Modification of a commercial palladium hydride reference electrode (PdH RE) allows for rapid temperature cycling under cryogenic conditions in aprotic organic solvents. Validation of the setup with the well‐known Ferrocene|Ferrocenium (Fc|Fc+) redox couple gave good compliance with literature data at room temperature in a range of organic solvent‐based electrolytes. Evaluation of temperature‐dependent diffusion kinetic parameters, such as diffusion coefficients (D) and diffusional activation energies (Ea,D) from CVs at multiple potential scan‐rates and temperature levels emphasize the reliability of the presented cryo‐electrochemical setup.

Dedicated to Prof. Wolfgang Beck on the occasion of his 90th birthday.The aggregation behavior of an amphiphilic copper(II) complex was studied in solution by means of UV-Vis and EPR spectroscopy. While dilute solutions in polar media do not give indication of relevant intermolecular interactions, concentrated solutions in nonpolar media clearly do not reflect the molecular properties of [CuL] (H 2 L: N 2 O 2 ligand of the Jäger-type with bulky head-group and long alkoxy tailing). Massive broadening of EPR-lines is prevalent in non-polar media, such as n-heptane and iso-octane. In combination with DFT-modelling, the solvent-dependence of the EPR response (line widths and Cuhyperfine coupling) could be associated with the formation of oligomers with weak anti-ferromagnetically coupled copper centers. Weak anti-ferromagnetic coupling becomes evident also by SQUID magnetometry at T < 10 K of solid samples of [CuL]. The tendency towards supramolecular aggregation is unequivocally shown by electron microscopy of dried (TEM) and frozen samples (cryo-TEM). While the former approach gives evidence of the formation of extended 2D sheet-like structures with extensions on the micrometer scale, the latter technique identifies the formation of 1D thread-like structures with lengths of several hundred nanometers.