Preface—JES Focus Issue on Organic and Inorganic Molecular Electrochemistry

The Organic & Bioelectrochemistry technical area for the Journal of The Electrochemical Society presents a timely issue focused on organic and inorganic molecular electrochemistry. The work of the collaborating technical editor, John N. Harb (Brigham Young University) and guest editors for the focus issue, Sylvain Canesi, (Université du Québec à Montréal), Jean-Philip Lumb (McGill University), Song Lin (Cornell University), John N. Harb (Brigham Young University), Matthew Graaf (AbbVie), the numerous reviewers and the selected authors are gratefully acknowledged.

Organic chemists increasingly appreciate the ability of electrochemistry to perform chemoselective and efficient syntheses, while also providing a powerful analytical tool to investigate reaction mechanisms.

Electroorganic chemistry/synthesis has been studied for nearly 200 years. Faraday and Kolbe pioneered the first organic electrochemical transformation, developing the venerable Kolbe reaction between 1830 to 1850. later (1898), Haber published an important paper on the electroreduction of nitrobenzene leading to the development of an electrochemical process for the synthesis of azo dyes. In 1964, Manuel Baizer published a seminal paper demonstrating the influence of the double layer on the outcome of an electrochemical reaction. This led to the development of the Baizer-Monsanto electrosynthesis of adiponitrile in a continuous flow reactor Up to 180 000 MT/year were produced world wide with this process . Although it is no longer used, it provides an attractive illustration of reaction discovery and its scale-up, which is facilitated by electrochemical processes. The first half of the twentieth century saw the invention of polarography by Heyrovský (Nobel prize, 1959) (reported in 1920) and of the potenstiostat by Hickling (reported in 1942), two important devices which contributed to the development of organic electrochemistry. Further development of tools and the theoretical foundations for the study of reaction kinetics and mechanism continued actively in the 1960s–1990s: cyclic voltammetry with macro- and microelectrodes, linear sweep voltammetry at rotating disk and rotating ring-disk electrodes, pulse voltammetry (normal and differential), square wave voltammetry, spectro-electrochemistry, computational simulation of voltammograms. These tools played and continue to play an important role in the development of organic electrochemistry.

In the last 20 years, there has been a remarkable renaissance in the field of organic electrosynthesis, which is leaving its mark in mainstream synthetic organic chemistry laboratories. This is in part because recent electrochemical instrument advances provide several advantages over traditional synthetic methodologies including portability, user-friendliness, and low cost to carry various types of electrolyses (i.e., voltammetric, potenstiostatic, or galvanostatic).

The use of electrochemistry also offers "clean" electrons capable of replacing dangerous and toxic reagents via safer, straightforward, and energy efficient in situ electrogeneration. Electrosynthesis likewise enables atom economy and elimination of waste by using, for example, homogeneous electrocatalytic reactions, where the catalyst or the mediator (coordination complex, chiral molecule, or enzyme) is regenerated directly at the electrode (redox catalysis). Non-trivial chemical transformations can also be accessible via electrosynthesis due to precise control of the working electrode potential. Scaling up of electrolyses is relatively easy. This feature has stimulated its use in areas of fine chemicals, environmental mitigation, pharmaceuticals, agrochemicals, and others at the industrial scale.

With the growing need to develop efficient, environmentally friendly and selective (chemo-, regio- stereo-) chemical transformations, more and more synthetic organic chemists are considering electrochemistry. This need calls for increased collaborative efforts between synthetic organic chemists and experts in electroanalytical tools, electrode design and materials, spectroelectrochemistry, and in other fields of electrochemistry (energy conversion, batteries, sensors) with the hopes of inspiring the invention of new reactions, and of providing an increased number of large-scale organic electrosynthetic processes.