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Two‐dimensional conjugated metal–organic frameworks (2D c‐MOFs) are emerging as promising electrode materials for electrochemical energy storage devices. However, a viable path to realize superior dual‐ion storage in 2D c‐MOFs has remained elusive. Here, we report the synthesis of Cu2(Nx−OHPTP) 2D c‐MOFs (x=0,1,2; OHPTP=octahydroxyphenanthrotriphenylene) with precise aromatic carbon‐nitrogen arrangements, based on the π‐conjugated OHPTP ligand incorporated with one or two nitrogen atoms. The skeletal nitrogen modification in Cu2(Nx−OHPTP) allows the synergistic introduction of additional redox sites, and thus substantially favors the unique dual‐ion adsorption capacity. Consequently, the Cu2(N2−OHPTP) cathode exhibits a largely enhanced electrochemical performance for dual‐ion storage (i.e., Li+ and Cl‐) with a high specific capacity of 53.8 mAh g−1, which is twice that of Cu2(N0−OHPTP) and 1.3 times that of Cu2(N1−OHPTP). Furthermore, the Cu2(N2−OHPTP) electrode displays a favorable rate performance of 52 % and good cycling stability of 96 % after 1000 cycles. We identify N‐centered redox sites as additional Li+ adsorption sites by combining ex situ and in situ spectroscopy measurements and theoretical calculations. In addition, calculations underline the synergistic enhancement of the Cl− adsorption energy by about 1.0 eV at the more electron‐poor CuO4 linkages after N‐incorporation. This work paves the way for the precise design of 2D c‐MOFs with superior electrochemical properties, advancing their application in dual‐ion storage applications. [ABSTRACT FROM AUTHOR]

Zweidimensionale konjugierte metallorganische Gerüstverbindungen (2D c‐MOFs) gehören zu einer einzigartigen Gruppe elektronischer Materialien. 2D c‐MOFs mit Bandlücken im sichtbaren oder nahen IR‐Bereich und hohen Ladungsträger‐mobilitäten sind jedoch rar. Die meisten literaturbekannten halbleitenden 2D c‐MOFs sind metallisch, was ihre Verwendung in logischen Bauelementen stark einschränkt. Im Folgenden konzipieren wir einen Phenanthrotriphenylen basierten, D2h‐symmetrischen, π‐konjugierten Liganden (OHPTP) und synthetisieren die ersten rhombischen 2D c‐MOF Einkristalle (Cu2(OHPTP)). Kontinuierliche Rotations‐Elektronendiffraktometrie (cRED) belegt die orthorhombische Kristallstruktur mit versschobene AA‐Schichtung auf atomarer Ebene. Cu2(OHPTP) ist ein p‐Typ Halbleiter mit einer indirekten Bandlücke von ≈0.50 eV, einer hohen elektrischen Leitfähigkeit von 0.10 S cm−1 und einer hohen Ladungsträgermobilität von ≈10.0 cm2 V−1 s−1. Theoretische Berechnungen unterstreichen die dominierende Rolle des Ladungstransports zwischen den Schichten in diesem Semichinon verknüpften 2D c‐MOF. [ABSTRACT FROM AUTHOR]

Two‐dimensional conjugated metal–organic frameworks (2D c‐MOFs) are emerging as a unique class of electronic materials. However, 2D c‐MOFs with band gaps in the Vis‐NIR and high charge carrier mobility are rare. Most of the reported conducting 2D c‐MOFs are metallic (i.e. gapless), which largely limits their use in logic devices. Herein, we design a phenanthrotriphenylene‐based, D2h‐symmetric π‐extended ligand (OHPTP), and synthesize the first rhombic 2D c‐MOF single crystals (Cu2(OHPTP)). The continuous rotation electron diffraction (cRED) analysis unveils the orthorhombic crystal structure at the atomic level with a unique slipped AA stacking. The Cu2(OHPTP) is a p‐type semiconductor with an indirect band gap of ≈0.50 eV and exhibits high electrical conductivity of 0.10 S cm−1 and high charge carrier mobility of ≈10.0 cm2 V−1 s−1. Theoretical calculations underline the predominant role of the out‐of‐plane charge transport in this semiquinone‐based 2D c‐MOF. [ABSTRACT FROM AUTHOR]