Fred Wudl. A giant in π-conjugated materials

This themed issue of Materials Chemistry Frontiers is a tribute to Professor Fred Wudl, one of the pioneers of organic electronics, on the occasion of his 80th birthday. Wudl's contributions in the design of new π-conjugated molecules and materials have defined this field, through numerous milestone discoveries, ranging from small-molecules-based organic metals, ferromagnets and superconductors, to fullerene acceptors and low bandgap polymers. Fred's remarkable creativity and perpetual scientific curiosity have received wide international recognition and led to many awards including the Arthur C. Cope Scholar Award, the Chemistry of Materials Award and the Tolman Medal from the American Chemical Society; the Wheland Medal from the University of Chicago; the Spiers Memorial Award and Stephanie L. Kwolek Award from the Royal Society of Chemistry; and Seaborg Medal from the University of California, Los Angeles.

Wudl's work continues to inspire many scientists to push the advance of materials chemistry. In this themed issue, you will find 24 reviews, communications and full articles covering the synthesis of new conjugated molecules and polymers, the study of structure–properties relationships, and applications in various devices including solar cells, organic field-effect transistors (OFETs), organic light-emitting diodes (OLEDs) and sensors.

Many papers in this themed issue evolve from Fred's early work in materials chemistry and have been presented by many of his former coworkers and colleagues. The diversity of the presented contributions reflect that of Fred's own career. These include the review on azaacenes by Zhang and Zhang (DOI: 10.1039/C9QM00656G), propellant-based electron acceptors by Zhang et al. (DOI:10.1039/D0QM00279H), anthracene-based liquid crystals by Meng et al. (DOI: 10.1039/D0QM00305K), stable radicals by Zheng et al. (DOI: 10.1039/D0QM00122H), and polymers by Wei and Wang (DOI: 10.1039/D0QM00309C); and papers on conjugated polyelectrolytes by Nguyen et al. (DOI: 10.1039/D0QM00073F) and by Chiechi et al. (DOI: 10.1039/D0QM00278J), pyridine/selenophene copolymers by Yang et al. (DOI: 10.1039/C9QM00739C), 2D perovskites by Dou et al. (DOI: 10.1039/D0QM00233J), chemical and biological sensors based on OFETs by Miao et al. (DOI: 10.1039/D0QM00202J), non-fullerene acceptor by Chen et al. (DOI: 10.1039/D0QM00287A), thermally activated delayed fluorescence (TADF) by Bryce, Monkman et al. (DOI: 10.1039/D0QM00429D), donor–acceptor co-crystals by Coropceanu, Brédas et al. (DOI: 10.1039/D0QM00420K) and by Perepichka et al. (DOI: 10.1039/D0QM00500B), doping of organic and perovskite semiconductors by Chabinyc et al. (DOI: 10.1039/D0QM00442A), rylene diimides by Guldi, Prato et al. (DOI: 10.1039/D0QM00407C). One of these papers builds on Fred's famous isothianaphthene motif to create new n-type semiconductors and has been co-authored by Fred (DOI: 10.1039/D0QM00137F).

During the preparation of this themed issue, we received a hugely enthusiastic response from researchers in the organic electronics community, which was not surprising given Fred's pioneering role in the field. We hope that you will enjoy reading through this issue.

Although Professor Wudl has now retired, he remains an active member of the scientific community (Fig. 1). His “what's the story?” (addressed daily to his students and post-docs) will be remembered for many years. Happy Birthday, Fred, and many more to come!

Fig. 1 Professor Fred Wudl at the International Symposium on Optoelectronics, Materials, and Energy (iSOME-2014) in Nanjing 2014, and the following social activities with his wife Dr Linda Wudl.

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