66749-96-0Relevant articles and documents
A new colorimetric and fluorescent chemosensor based on Schiff base-phenyl-crown ether for selective detection of Al3+ and Fe3+
Dong, Guangcui,Duan, Kaifei,Zhang, Qiang,Liu, Zizhong
, p. 322 - 330 (2019)
A novel chemosensor (L) based on Schiff base-phenyl-crown ether was synthesized and evaluated as a chemoselective Al3+ and Fe3+ sensor in ethanol through “turn-on” fluorescence enhancement and sharp colorimetric responses. Adding 10 equiv. Al3+ or Fe3+ could change the color of the sensor L from colorless to orange yellow, and increase the fluorescence intensity of L at 596 nm by 160-fold or 130-fold, respectively. The selective response of L to Al3+ and Fe3+ was not interfered by other ions, and their bonding was reversible. The results of fluorescence spectral titration data showed that the association constants (lgKs) of L for Al3+ and Fe3+ were 8.95 and 8.67 in ethanol, and the corresponding detection limits were 0.33 and 0.36 μM, respectively. The Job's plot and mass spectrometry revealed that the sensor L formed a 2:1 complex with Al3+ or Fe3+. The proposed binding modes of L with Al3+ and Fe3+ were demonstrated by means of the infrared spectroscopy and 1H NMR titration. The results of DFT/B3LYP calculations showed that the binding with Al3+ and Fe3+ makes the sensor L accompanied a mechanism with the inhibition of C[dbnd]N isomerization (cis-trans) and the activation of chelation enhanced fluorescence (CHEF).
A multi-responsive crown ether-based colorimetric/fluorescent chemosensor for highly selective detection of Al3+, Cu2+ and Mg2+
Zhang, Qiang,Ma, Ruifang,Li, Zhuying,Liu, Zizhong
, (2019/12/09)
A novel multi-response chemosensor L based on coumarin-chalcone-crown ether was designed and synthesized, which exhibited a high selectivity for the colorimetric detecting Al3+ and Cu2+ and fluorescent recognizing Al3+ and Mg2+ in ethanol. L can monitor Al3+ and Cu2+ via distinct color changes from a slight yellow to pink and to orange, respectively. The sensor L can also monitor Al3+ and Mg2+ by fluorescence emission responses at 592 nm and 547 nm with low detection limits of 0.31 μM and 0.23 μM, respectively. The selectivity of L toward Al3+, Cu2+ and Mg2+ was not interfered by a large number of coexisting ions and was found to be reversible. By means of spectrometric titration, Job's plot, mass spectrometry, 1H NMR titration and IR spectroscopy analysis, it was unanimously confirmed that the sensor L had a stoichiometric ratio of 1:1 with Cu2+ and Mg2+, and 1:2 with Al3+. The order of the stability of the complexes formed by L and Al3+, Cu2+, Mg2+ was as follows: L-Al3+ > L-Cu2+ > L-Mg2+. At the same time, some possible bonding modes and sensing mechanisms were further proposed, and the optimized structure of the sensor L and its sensing mechanism for Al3+, Cu2+ and Mg2+ were confirmed by the calculations of DFT/B3LYP and TD-DFT methods in a suite of Gaussian 09 programs.
Precious metal-free molecular machines for solar thermal energy storage
Kandinska, Meglena I.,Kitova, Snejana M.,Videva, Vladimira S.,Stoyanov, Stanimir S.,Yordanova, Stanislava B.,Baluschev, Stanislav B.,Angelova, Silvia E.,Vasilev, Aleksey A.
supporting information, p. 1096 - 1106 (2019/06/08)
Four benzothiazolium crown ether-containing styryl dyes were prepared through an optimized synthetic procedure. Two of the dyes (4b and 4d) having substituents in the 5-position of the benzothiazole ring are newly synthesized compounds. They demonstrated a higher degree of trans-cis photoisomerization and a longer life time of the higher energy forms in comparison with the known analogs. The chemical structures of all dyes in the series were characterized by NMR, UV-vis, IR spectroscopy and elemental analysis. The steady-state photophysical properties of the dyes were elucidated. The stability constants of metal complexes were determined and are in good agreement with the literature data for reference dyes. The temporal evolution of trans-to-cis isomerization was observed in a real-time regime. The dyes demonstrated a low intrinsic fluorescence of their Ba2+ complexes and high yield of E/Z photoisomerization with lifetimes of the higher energy form longer than 500 seconds. Density functional theory (DFT) calculations at the B3LYP/6-31+G(d,p) level were performed in order to predict the enthalpies (H) of the cis and trans isomers and the storage energies (ΔH) for the systems studied.
