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Due to their versatility and easy processing, Surface-Anchored Metal–Organic Frameworks (SurMOFs) have gained interest in recent times as promising electrochromic thin films. Herein a step forward in their use and characterization was achieved thanks to the integration of {Zn2(PDICl4)2} SurMOFs in a multi-layer electrochromic device (ECD), based on a membrane-like electrolyte. The optical and electrochemical properties of the ECD were fully characterized, revealing a two-step reduction process localized on the organic ligand and involving subsequent near infra-red (NIR) and cyan absorbing states, leading to optical modulation of the films. The species responsible for this absorption were isolated and identified in the reduced states. In parallel to experimental characterization, quantum chemistry was successfully used to investigate the structure–property relationship of the SurMOF, revealing additional information regarding the structure and the local environment of the electrochromic ligand. [ABSTRACT FROM AUTHOR]

Novel electrochromic hybrid thin films are synthesized following a liquid‐phase epitaxy in a layer‐by‐layer fashion, yielding highly oriented surface‐anchored metal–organic frameworks (SurMOFs). The initial orange color of this {Zn2(PDICl4)2} crystalline thin films is reversibly switched by electrochemical reduction. In a lithium‐based electrolyte, a dark blue color is obtained in few seconds with a color efficiency of 104.8 cm2 C−1 (λ = 645 nm). Interestingly, the color of the reduced state is easily modulated by changing the electrolyte composition. Clearly, two different mechanisms are implicated and the reduced species responsible of the color are identified. Taking advantage of this unusual property, electrochromic devices with a novel configuration are designed leading to an original prototype capable of reversibly switching from a single initial orange color to two different colors simultaneously, namely dark blue and cyan. [ABSTRACT FROM AUTHOR]