Integrated Photoresponsive Alkaline Earth Metal Coordination Networks: Synthesis, Topology, Photochromism and Photoluminescence Investigation

Abstract

Photoresponsive materials are a key part of the age of smart technology that have potential in a broad range of applications. Coordination networks (CNs) are widely used due to their designability and stability. In this work, three novel alkaline earth metal coordination networks (AEM‐CNs): [Mg(CMNDI)(H2O)2], [Ca(CMNDI)(H2O)2]⋅H2O, and [Sr(CMNDI)(H2O)(DMF)] with fsl, cds, and scn topology nets were synthetized via N,N’‐bis(carboxymethyl)‐1,4,5,8‐naphthalenediimide (H2CMNDI); the scn net is not found in the Reticular Chemistry Structure Resource or ToposPro. The reusable and sensitive photochromic properties of the three CNs enable them to be used as secret inks or ultraviolet detectors. In addition, the CNs also exhibited reusable photoluminescent turn‐off toward the drug molecules, balsalazide disodium (Bal.) and colchicine (Col.), with good limits of detection of 0.16 and 0.70 μM. To the best of our knowledge, this is the first study of a fluorescence sensor for Bal. Thus, the AEM‐CNs provide a design idea for integrated photoresponsive materials that could be further improved in the near future by further study.

Stimuli-Responsive Naphthalenediimide Cd-MOFs Tuned by Different Aliphatic Dicarboxylic Acids with Extended Spacers

“…Based on the above properties, we have a reason to believe that complexes 1−9 can serve as secret erasable inks. 27 Generally, complex 2 was drawn on kraft in some character, the color of which was so close to that of complex 2 that it was difficult to visualize with the naked eye (Figure 10a). After it was irradiated for 0.5 h, previously drawn characters were visualized in full (Figure 10b).…”

“…Based on previous studies on NDI derivatives, the NDI moiety is known to be redox-active and capable of generating free radicals after irradiation, and two major absorption bands at 490 and 700 nm are assigned to the photoinduced electron-transfer transition of the NDI derivatives, so we judge that the color change of complexes 1–9 is most likely caused by the photoinduced NDI radical generation of the NDI-A ligand (Scheme ). This conjecture was also revealed in atomic force microscopy (AFM) images (Figures S28–S45). The topography of materials was usually characterized by AFM, and the silicon substrate scanned was covered by the samples and all scanning areas were 20 μm × 20 μm.…”

“…Also, this photochromic behavior of complexes 1 – 9 can be cycled three times or more (Figure S18). Based on the above properties, we have a reason to believe that complexes 1–9 can serve as secret erasable inks . Generally, complex 2 was drawn on kraft in some character, the color of which was so close to that of complex 2 that it was difficult to visualize with the naked eye (Figure a).…”

Photochromic Metal–Organic Framework for High-Resolution Inkless and Erasable Printing

“…Vilogen, 1,4,5,8-naphthalenediimide (NDI) core, and their derived ligands, which possess redox-active cores and exhibit reversible photochromism, are usually used to construct photochromic MOFs. For example, [Zn 4 (CEBPY) 2 (IPA) 3 (OH) 2 ]·2H 2 O and [Ca­(CMNDI) (H 2 O) 2 ]·H 2 O (CEBPY = N -carboxyethyl-4,4′-bipyridinium, H 2 IPA = isophthalic acid, and H 2 CMNDI = N , N ′-bis­(carboxymethyl)-1,4,5,8-naphthalenediimide) have been used for inkless and erasable printing of simple pictures. ,− However, most of them are limited to some simple printing patterns (pictures or photos), and cannot achieve high-resolution printing contents in some practical systems (such as printing texts) because of the short photo-generated color lifetime and poor color contrast before and after light irradiation. , As far as we know, the photochromic [M 2 (BINDI)] (M = Mg II , Ca II , and Sr II ,H 4 BINDI = N , N ′-bis­(5-isophthalic acid)­naphthalenediimide) is the only reported MOF that can be truly used to achieve practical and high-resolution printing contents in texts . However, there is still a significant gap for inkless and erasable printing to achieve the higher-resolution text printing of daily inks and laser printers.…”

Reversible Photochromic Coordination Polymer by Phototriggered Subtle Molecular Conformation Variations

“…In the past few years, photochromic molecules (azobenzene, diarylethene, spiropyran, viologen, etc.) have also been introduced to the poral surfaces as struts or to the pores of CPs as guest molecules in order to control the properties by light, , potentially leading to an on-demand function for molecular storage, anticounterfeiting, sensing, and photooptical switch component separation and catalysis. − However, free radicals cannot be returned to their initial states only under exposure of irradiation, leading to severe reduction of the responsive speed, durability, and reversibility of solid-state photochromic materials. Besides, dramatic structural changes can cause morphology destruction.…”