The quest for single component molecular metals within neutral transition metal complexes

Abstract

Twenty years ago, the molecular materials community accomplished a major breakthrough with the report of the first single component molecular metal (SCMM). Previously it was believed that molecular metals had...

Proton–electron-coupled functionalities of conductivity, magnetism, and optical properties in molecular crystals

“…This results in richer and multiple electronic functionalities, such as magnetic and optical properties, and electrical conductivity, which are based on stable multi-redox activities and smaller HOMO-LUMO gaps. [46][47][48][49][50][51][52][53][54] In terms of proton-electron coupling, stable multi-redox activities are especially advantageous for realizing (de)protonation-responsive functionalities. Additionally, transitionmetal complexes offer facile modification routes based on various combinations of central metals and organic ligands.…”

Comparative Structural Studies of Ni vs. Au Metal Bis‐dithiolene Complexes with a Thiazole Backbone [M(R‐thiazdt)2]

“…[19] For all the investigated complexes three redox processes can be observed on the cyclic voltammogram. Upon anodic scan, the mononanion radical is reversibly oxidized to the neutral species at E 2 (À 1/0) and then to the monocationic complex at E pa 3 . The later process is not fully reversible as can be seen in Figure 1.…”

“…Thus, the lack of counterion can increase the intermolecular interactions between the electroactive components and generate highly conducting materials. [1][2][3][4][5] These neutral complexes, despite their neutral structure, present some differences as the neutral gold bis(dithiolene) complexes are open-shell species while the neutral nickel complexes are closed-shell species. Another interesting point is their organization in the solid state.…”

“…In the two last decades, nickel and gold bis(dithiolene) complexes have received a special attention as precursors of single component molecular conductors [1][2][3] especially after the discovery of highly conducting complexes involving two TTFdithiolate ligands around the metal center. [4][5] This active research topic is motivated by the advantages that singlecomponent materials can bring, compared to multi-component materials (ion radical salts, charge transfer salts) where one of the components, the counterion, rather plays a spectator role.…”

“…This active research topic is motivated by the advantages that single‐component materials can bring, compared to multi‐component materials (ion radical salts, charge transfer salts) where one of the components, the counterion, rather plays a spectator role. Thus, the lack of counterion can increase the intermolecular interactions between the electroactive components and generate highly conducting materials [1–5] . These neutral complexes, despite their neutral structure, present some differences as the neutral gold bis(dithiolene) complexes are open‐shell species while the neutral nickel complexes are closed‐shell species.…”