The impact of metal ions on photoinduced electron-transfer properties: four photochromic metal–organic frameworks based on a naphthalenediimide chromophore

Abstract

Four photochromic MOFs show that electron-withdrawing capabilities of metal ions play a significant role in tuning the photosensitivity of photochromic MOFs.

Coordination Polymers Based on Highly Emissive Ligands: Synthesis and Functional Properties

“…In addition, these compounds exhibited a color change upon exposure to nitrite ions and different solvents (Figure 11). 5) [175]. All of the complexes were photochromic and their photosensitivity increased in the order Ba(II) < Ca(II) < Cd(II) < Zn(II), consistent with the order of electronegativity for these ions.…”

“…•7DMF} (H 4 bindi-N,N -bis(5-isophthalic acid)naphthalenediimide, Table 5) [175]. All of the complexes were photochromic and their photosensitivity increased in the order Ba(II) < Ca(II) < Cd(II) < Zn(II), consistent with the order of electronegativity for these ions.…”

Highly Selective Chloromethanes Detection Based on Quartz Crystal Microbalance Gas Sensors with Ba-MOFs

“…As stated in the crystal structure, the coordination numbers of all Ba 2+ ions in 1 and 2 are 10, while the coordination numbers of the four Ba 2+ ions in 3 are 8, 9, 10, and 9 (Table S5), and all the Ba 2+ ions in 1 – 3 have water molecules involved in the coordination. To our knowledge, the highest coordination number of Ba 2+ is 10, − and chloromethanes possess the ability to dissociate the solvent coordination bonds and coordinate with hard metal ions. , So 1 and 2 with high selectivity to chloromethanes are mainly due to the exchange of coordination water molecules with CH 2 Cl 2 , CHCl 3 , and CCl 4 and possible electrostatic effects between (CH 3 NH 3 ) + cations and chloromethanes with more electronegative chlorine atoms.…”

Structural characterization and photochromic behaviour of a novel compound based on a π-acidic naphthalene diimide derivative and a double hydroxide-bridged dinuclear AlIII aqua ion cluster

“…with the formation of organic radical anions (Leong et al, 2014;Garai et al, 2016;Liao et al, 2017Liao et al, , 2018Fu et al, 2018;Xu et al, 2018). As mentioned above, the abundant noncovalent interactions, such as hydrogen bonding,stacking and lone-pair-interactions, can offer effective pathways for charge transfer.…”

“…5). That is to say, the observed ESR signal stems from the noncovalent interaction-induced charge transfer of the TauNDI 2À anions to generate stable organic radical anions as a result of the reduction of the neutral NDIs species, which leads to a long-lived charge-separated state (Leong et al, 2014;Garai et al, 2016;Liao et al, 2015Liao et al, , 2016Liao et al, , 2017Liao et al, , 2018Fu et al, 2018;Xu et al, 2018). Notably, once the sample is irradiated with additional light, the intensity of the signal of the organic radicals increases obviously, in other words, the degree of charge transfer for these crystals increases with prolonged illumination time (Fig.…”