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Various naphthalenediimide (NDI) based electron donor–acceptor coordination polymers (D–A CPs) have been constructed and used to explore charge transfer (CT) and electron transfer (ET) behaviors. Up to now, significant progress has been made in the interface contact and electron donor–acceptor ability matching mechanism, while the electronic density effect of the electron donors on the CT and ET behaviors is still not known. Herein, two NDI-based D–A CPs, [Cd2(H2NDI)(IPA)2(H2O)2] (1) and [Cd2(H2NDI)(IPA-OH)2(H2O)2] (2), are constructed using an NDI-based ligand and two aromatic carboxylic acid ligands (H2NDI = 2,7-bis(3,5-dimethyl) dipyrazol-1,4,5,8-naphthalene tetracarboxydiimide, H2IPA = isophthalic acid; and H2IPA-OH = 5-hydroxyisophthalic acid). UV-vis and EPR spectroscopy and DFT calculations analyses reveal that the occurrence of themal electron transfer (TET) in 1 and 2 results from the HOMO of the IPA and IPA-OH lying higher than the LUMO of the NDI. Meanwhile, compared to 1, the UV-vis absorption spectrum of 2 exhibits a significant red shift, which suggests higher electron density of the donor and more electron transfer pathways are beneficial for the occurrence of intermolecular CT. After UV light irradiation, the comparison of the photochromic behavior of 1 and 2 confirms the negative effect of the stronger CT on photoinduced electron transfer (PET). The present study illustrates the delicate modulating effect of electron density on the CT and ET behaviors in D–A CPs. [ABSTRACT FROM AUTHOR]

Numerous techniques have focused on the ability of p-sulfonated calix[n]arene to form complexes with tryptophan. Scanning electron microscopy and Fourier transform infrared spectroscopy were utilized to study the organization and molecular structure of different layers of the electrode surface. Scanning electron microscopy results showed that SC4A displayed a cubic structure whereas SC6A and SC8A displayed dendrite structures. The electrochemical properties and potential complex formation between SCnA and tryptophan were characterized by cyclic voltammetry and electrochemical impedance spectroscopy. Cyclic voltammetry experiments showed that the gold electrode was successfully functionalized by self-assembled cysteamine and SC4A. Electrochemical impedance spectroscopy results showed the observation of the tryptophan-SCnA interaction and indicated that SC4A had the highest sensitivity to tryptophan and allowed 2.04 µg [L.sup.-1] tryptophan to be detected. Electrochemical impedance spectroscopy analysis and molecular modeling calculation confirmed that SC4A has higher tryptophan sensitivity than SC6A and SC8A. Key words: Fourier transform infrared spectroscopy, molecular modeling calculation, cyclic voltammetry, electrochemical impedance spectroscopy, scanning electron microscopy. De nombreuses techniques ont ete axees sur la capacite des calix[n]arenes p-sulfones a former des complexes avec le tryptophane. La microscopie electronique a balayage et la spectroscopie infrarouge a transformee de Fourier ont ete utilisees pour etudier l'organisation et la structure moleculaire de differentes couches de la surface de l'electrode. Les resultats de la microscopie electronique a balayage ont montre que SC4A presentait une structure cubique alors que SC6A et SC8A possedaient des structures dendritiques. Les proprietes electrochimiques et la formation possible d'un complexe entre SCnA et le tryptophane ont ete caracterisees par voltammetrie cyclique et spectroscopie d'impedance electrochimique. Les experiences de voltammetrie cyclique ont montre que l'electrode en or etait fonctionnalisee avec succes par autoassemblage de cysteamine et de SC4A. Les resultats de la spectroscopie d'impedance electrochimique ont permis d'observer l'interaction tryptophane-SCnA et ont revele que SC4A avait une sensibilite elevee au tryptophane et qu'une concentration en tryptophane de 2,04 µg [L.sup.-1] pouvait etre detectee de cette technique d'analyse. Les calculs de modelisation moleculaire et les resultats de la spectroscopie d'impedance electrochimique ont confirme que SC4A presentait une plus grande sensibilite au tryptophane que SC6A et SC8A. [Traduit par la Redaction] Mots-cles : spectroscopie infrarouge a transformee de Fourier, calculs de modelisation moleculaire, voltammetrie cyclique, spectroscopie d'impedance electrochimique, microscopie electronique a balayage., Introduction As the third major class of host molecules, calixarenes, (1) which are synthesized by the condensation between p-alkylphenol and formaldehyde under basic conditions, have attracted much attention due to [...]

Comprehensive Summary: Better understanding the determining factors of dynamic magnetic relaxation in polynuclear lanthanide based single‐molecule magnets (SMMs) remains a challenge due to the complexity of such architectures involving interactions between the magnetic centers. To address this issue, two structurally related heterometal DyIII2ZnII2 SMMs, [Zn2Dy2(L)4(Ac)2(DMF)(CH3OH)]·CH3OH·2H2O (1) and [Zn2Dy2(L)4(Ac)2(DMF)2]·4CH3CN (2) (H2L = (E)‐2‐((2‐hydroxy‐3‐methoxybenzylidene)amino)‐4‐methyphenol, DMF = N,N‐dimethylformamide), are introduced and investigated. Through modifying the auxiliary ligands on one DyIII site while retaining that on the other DyIII, the intramolecular magnetic interactions and relaxation dynamics in these two heterometallic‐DyIII2ZnII2 SMMs can be tuned, demonstrating a dramatic change in the magnet relaxation behavior with energy barrier changing from a negligible value for 1 to 305 K for 2. Ab initio calculations reveal that changing the coordination geometries on the DyIII sites can significantly affect the magnetic interactions as well as single‐ion anisotropy. [ABSTRACT FROM AUTHOR]

The inclusion complex formation of nereistoxin (NTX) with cucurbit[7] uril (CB[7]) in aqueous solution was investigated by competitive binding of palmatine (PAL) fluorescent probe. The CB[7]-PAL complex exhibited high fluorescence in aqueous solution, which was quenched in the presence of NTX. This is due to the extrusion of PAL from the CB[7] cavity into the aqueous phase by NTX. The association constants (K) for the inclusion complexation of the host and guest were determined. The encapsulation of NTX and PAL as they compete for occupancy of the CB[7] cavity was studied using absorption, spectrofluorimetry, 1H NMR, and molecular modelling calculations. [ABSTRACT FROM AUTHOR]