The Cover Feature shows the color changes achieved, upon oxidation, by newly synthesized electrochromic oxygen‐doped small molecules. The crucial moieties are furano and pyrano. Incorporation of these groups into other organic molecules can be used to greatly expand the library of electrochromic small molecules, giving very good control over color transition observed. Such controlled color changes could take electrochromism from the niche applications it currently occupies, to the wider world. Cover design by Adriana Lopez‐Biagi. More information can be found in the Full Paper by D. Bonifazi et al.

In this work, we report the synthesis of O‐doped naphthalene‐based electrochromes. Exploiting the CuO‐mediated Pummerer oxidative cycloetherification reaction, a series of 1,4‐ and 1,5‐disubstituted naphthalene‐cored dipyrano, difurano, and furano‐pyrano polycyclic aromatic hydrocarbons (PAHs) have been prepared. Steady‐state UV‐Vis absorption and emission investigations showed that the spectroscopic profile strongly depends on the O‐doping topology, with the dipyrano and the difurano derivatives demonstrating the most red‐shifted and blue‐shifted electronic transition, respectively. Computational investigations revealed that the cycloetherification reaction raises the HOMO energy level (while the LUMO remains largely unaffected), with the dipyrano derivatives displaying the highest values. Spectroelectrochemical measurements showed that, depending on the O‐topology and the type of O‐ring, different electrochromic responses could be obtained with colour transitions featuring high contrasts involving yellow, pink, orange or blue colours.

A custom-built dual mode EPR resonator was used to study the radical chemistry of AIBN thermal decomposition. This resonator enables both simultaneous in situ heating using microwaves and EPR measurements to be performed. The thermal decomposition of AIBN was compared following conventional heating methods and microwave induced (or dielectric) heating methods. Under both heating conditions, the radicals formed and detected by EPR include the 2-cyano-2-propyl (CP●) and 2-cyano-2-propoxyl (CPO●) radicals. Under aerobic conditions, the observed relative distribution of these radicals as observed by EPR is similar following slow heating by conventional or dielectric methods. In both conditions, the kinetically favored CPO● radicals and their adducts dominate the EPR spectra up to temperatures of approximately 80-90 °C. Under anaerobic conditions, the distribution can be altered as less CPO● is available. However, the observed results are notably different when rapid heating (primarily applied using a MW induced T-jump) is applied. As the higher reaction temperatures are achieved on a faster time scale, none of the ST●-CPO adducts are actually visible in the EPR spectra. The more rapid and facile heating capabilities created by microwaves may therefore lead to the non-detection of radical intermediates compared to experiments performed using conventional heating methods.

A custom-built dual-mode EPR resonator was used to study the radical chemistry of AIBN thermal decomposition. This resonator enables both simultaneous in situ heating using microwaves and EPR measurements to be performed. The thermal decomposition of AIBN was compared following conventional heating methods and microwave-induced (or dielectric) heating methods. Under both heating conditions, the radicals formed and detected by EPR include the 2-cyano-2-propyl (CP●) and 2-cyano-2-propoxyl (CPO●) radicals. Under aerobic conditions, the observed relative distribution of these radicals as observed by EPR is similar following slow heating by conventional or dielectric methods. In both conditions, the kinetically favoured CPO● radicals and their adducts dominate the EPR spectra up to temperatures of approximately 80–90 °C. Under anaerobic conditions, the distribution can be altered as less CPO● is available. However, the observed results are notably different when rapid heating (primarily applied using a MW-induced T-jump) is applied. As the higher reaction temperatures are achieved on a faster timescale, none of the ST●-CPO adducts are actually visible in the EPR spectra. The more rapid and facile heating capabilities created by microwaves may therefore lead to the non-detection of radical intermediates compared to experiments performed using conventional heating methods.