Spotlight collection on inorganic molecular electronics

It is a privilege to welcome the readers of Dalton Transactions to this Spotlight Collection “Inorganic Molecular Electronics”. This collection aggregates several studies published between 2018 and 2023 discussing the structural, optical, electronic, magnetic and electrical properties of coordination and organometallic complexes in the context of molecular electronics. Emphasis was given to complexes that have been incorporated into electrode|molecule|electrode molecular junctions, aiming at the development of molecular components such as wires, rectifiers, transistors, on/off switches and memory elements. The collection also encompasses broader studies directed to applications of metal complexes in spintronics, single-molecule sensing systems, and an increasingly wide array of materials science applications including thermoelectrics.

Research towards inorganic molecular electronics first appeared in the late 1990s and early 2000s, and attracted a relatively small community, due to its demanding multidisciplinary nature and requirements that encompass theoretical, synthetic, analytical, and physical methods in order to deliver unique molecular systems with customized and controlled properties. The 16 articles published in this themed issue represent a common effort by groups from 24 universities located in Australia, China, France, India, Japan, Poland, Spain, the UK, and the USA selected following the usual rigorous peer review advocated by the Royal Society of Chemistry, to serve as an inspiring go-to collection to get an understanding of the field.

We include 2 Perspectives, 4 Frontiers, 1 communication and 9 full papers in this collection, with topics ranging from molecular-scale electronics, electron transport and rectification, switching, and optical, electronic, and stability properties. Molecular-scale electronics in porphyrins and phthalocyanines and in ligand-protected nanostructured surfaces, are reported in two papers by Cao et al. (https://doi.org/10.1039/D3DT01518A, https://doi.org/10.1039/D0DT02822C), and in photo-responsive and conductive coordination polymers in two other papers by Mir et al. (https://doi.org/10.1039/D3DT02768F, https://doi.org/10.1039/D0DT03222K). Electron transport is represented in phosphindole-fused pyrroles by Mathey et al. (https://doi.org/10.1039/C9DT01299K), in polyoxovanadates adsorbed on Au by de Graaf et al. (https://doi.org/10.1039/D1DT00731A), in metal acetylide and diethynylbenzene-bridged metal wires in two papers by Low et al. (https://doi.org/10.1039/C8DT02103A, https://doi.org/10.1039/D0DT01794A), in ferrocene-(ethynylphenyl) thioacetate wires by Bennett and Long (https://doi.org/10.1039/D3DT02954A); while current rectification through iron(III)- and ruthenium(II)-based metallosurfactants was discussed in three papers by Verani et al. (https://doi.org/10.1039/C8DT02891E, https://doi.org/10.1039/D3DT01797D, https://doi.org/10.1039/D2DT00938B) and in a eutectic GaIn|LB monolayer|Au sandwiches by Metzger et al. (https://doi.org/10.1039/C8DT00562A). Molecular switches based on luminescent porphyrins are studied by Rigaut et al. (https://doi.org/10.1039/C8DT01493K). Other studies include the optical and electronic properties of pyridinium-based bismuth iodide complexes and the air-stability of metal terpyridine complexes on surfaces, respectively discussed by the groups of Szaciłowski et al. (https://doi.org/10.1039/D3DT02910G) and Inkpen et al. (https://doi.org/10.1039/D3DT00955F).

Beyond the scientific breadth and depth, we have strived to be representative of the research community in terms of gender, racial, and regional diversity. We hope to inspire the need for continuing diversity in the field.

We want to express our gratitude to every person who contributed to this issue, starting with the authors, and expanding to the reviewers and the dedicated staff at Dalton Transactions. We hope the reader will enjoy this Spotlight Collection as much as we enjoyed working on it.

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