RESUMEN
Various arylenediimides (ADIs) have been applied to construct photoresponsive coordination polymers (CPs), while the size effect of ADI π-conjugate systems on the photoresponsive behaviors in CPs has been overlooked in the past few years. Herein, we emphasize the size effect of ADI π-conjugate systems on photoinduced electron transfer (ET) in CPs, taking two Eu3+-based CPs, [Eu(H2BINDI)(BINDI)0.5(H2O)2]·NH2(CH3)2·8H2O (1) and [Eu2(BIPMDI)(DMF)4(NO3)2]·H2O·2DMF (2) [H4BINDI = N,N'-bis(5-isophthalic acid)naphthalenediimide; H4BIPMDI = N,N'-bis(5-isophthalic acid)pyromellitic diimide; DMF = N,N-dimethylformamide], as a case. Both 1 and 2 display ET-based photochromic behaviors with distinct photoresponsive rates and coloration contrast, which can contribute to the size effect of diimide cores on the interfacial contacts of electron donors/acceptors. Meanwhile, ET between the neighboring larger NDI cores of the H4BINDI ligands can block ligand-to-metal charge transfer and quench luminescence of the Eu3+ metal center in 1. Therefore, this work will provide a theoretical basis for the development and exploration of photoresponsive materials.
RESUMEN
Two chloroantimonate hybrids with isomeric bipyridyltriazoliums and similar packing patterns, {[2-bpt]2[(SbCl5)Cl2]}n (1) and {[4-bpt]2[(SbCl5)Cl2]}n (2) (2-bpt2+ = protonated 3,5-bis(pyridine-2-yl)-1,2,4-triazole, 4-bpt2+ = protonated 3,5-bis(pyridine-4-yl)-1,2,4-triazole), have been designed and synthesized. Distinct intermolecular electronic interactions and photochromic behaviors are attributed to the remarkable modulation of positional isomeric effect on the electron deficiency of the acceptors and donor-acceptor matching relationship. 1 is the first reported photochromic chloroantimonate hybrid.
RESUMEN
Three isostructural halozincates, [HNH][ZnX4]·H2O (HNH2+ = protonated nicotinohydrazide, X = I (1), Br (2), Cl (3)), have been synthesized and exhibit halogen-dependent photoinduced electron transfer and chromic properties. Due to the different electron-donating nature of halogen atoms, only iodozincate hybrid 1 can easily undergo photoinduced electron transfer and eye-detectable photochromic behavior, revealing a unique matching rule between a moderate electron acceptor and halozincates.
RESUMEN
By using 1-methyl-4-(carbomethoxy)pyridinium (MCMP+) as counterions, two iodoargentate hybrids, 1D [MCMP][AgI2] (1) and 3D [MCMP][Ag3I4] (2) have been synthesized and they exhibit rare electron transfer photochromism with a fast response rate, a wide response range and a long-lived charge-separated state in iodometallate systems. Noteworthily, the marked differences in the structure and photochromic performance of 1 and 2 are largely ascribed to the different aggregating behavior of electron-deficient MCMP+ counterions (C-HO hydrogen bonded trimer in 1 and π-π/C-Hπ chain in 2).
RESUMEN
By employing in situ methylnicotinohydrazide dication (MNH(2+)) as an electron acceptor, we have constructed an iodocuprate(I) hybrid {[MNH][Cu2I3]2}n (1), which exhibits charge transfer (CT) thermochromism due to the intense absorption of CT and electron transfer (ET) photochromism with high photocoloration contrast and fast response to UV irradiation due to the synergetic effect of valence change of copper ions.
RESUMEN
Copolymer of acrylamide and 2-[(methacryloyloxy)ethyl]trimethylammonium chloride [P(AM-DMC)] is found to be effective to combine anionic dyes with strong aqueous solubility. This work aims mainly at revealing the interaction between anionic dyes and [P(AM-DMC)] by running jar test, spectra analysis and equilibrium dialysis experiments. The results show that P(AM-DMC) effectively decolorizes the tested strong water soluble anionic dyes, such as acidic, reactive and direct dyes, from their aqueous solutions under mild acidic and neutral conditions. Higher cationicity and optimal dose of flocculant P(AM-DMC) have to be used to achieve satisfactory and effective decolorization. Comparison of IR spectra of dye, flocculant P(AM-DMC) and the floc formed indicates chemical interaction occurred between sulfonic groups of dye and quaternary ammonium of flocculant. Plots of r-logC suggest cooperative interaction exists evidently for some dyes tested. Addition of KCl or urea reduces binding extent evidently, which shows the importance of electrostatic and hydrophobic interaction. Therefore the interaction between dyes tested and P(AM-DMC) might be controlled by hydrophobic, cooperative interaction and energetic interaction which includes chemical and electrostatic interactions.
