18019-52-8Relevant articles and documents
1,3-Bis(phenylamino)squaraine - Photophysical and photochemical properties
Kabatc, Janina,Kostrzewska, Katarzyna,Jurek, Katarzyna,Dobosz, Robert,Orze?, ?ukasz
, p. 179 - 186 (2016)
A novel squarylium dye possessing donor-π-acceptor structure that features a fixed imine phenyl ring as an electron donor and 3,4-dihydroxycyclobut-3-ene-1,2-dione moiety as an electron acceptor was synthesized. The structure of the dye was elucidated by means of NMR and IR spectroscopy and elemental analysis. The compound was studied using steady-state absorption and emission spectroscopy, as well as the time-resolved spectroscopy. The measurements were carried out in solvents of different polarity. The dye absorbs in the visible light region about 400 nm and emits light with low fluorescence quantum yield, below 1 × 10-3 M. An increases polarity of solvent results in a blue-shift of absorption band and red-shift of emission band, respectively. The rate constants of radiative and non-radiative deactivation of excited state depend on the viscosity of solvent used. The bimolecular quenching of excited singlet state of squaraine depends on the rate of diffusion process.
Bis(dicyanomethylene)squarate squaraines in their 1,2- and 1,3-forms: Synthesis, crystal structure and spectroscopic study of compounds containing alkali metals and tetrabutylammonium ions
de Oliveira, Vanessa E.,de Carvalho, Gustavo S.,Yoshida, Maria I.,Donnici, Claudio L.,Speziali, Nivaldo L.,Diniz, Renata,de Oliveira, Luiz Fernando C.
, p. 239 - 249 (2009)
In this paper, we describe a new synthetic methodology and the spectroscopic characterization of two squaraines 1,2- and 1,3-substituted, named sodium 1,2-bis(dicyanomethylene)squarate and sodium 1,3-bis(dicyanomethylene)squarate. The squaraine species are derived from 1,2-dihydroxycyclobuten-3,4-dione, also known as squaric acid. A modification in the synthetic route has been developed in order to improve the yield in the synthesis of the 1,3-derivative: the in situ use of the 1,3-dianilinesquarate intermediate. In both cases, an excess basic medium was added to the solution containing all the reactants. These squaraines consist of a cyanine-type chromophore with high thermal stability and several different spectroscopic properties. In addition, it was made a comparative analysis based on the spectroscopic study of the 1,3- and 1,2-compounds, as well as their derivatives with several metal alkalis (K+, Rb+, Mg2+, Ca2+, Sr2+ and Ba2+), besides tetrabutylammonium ion (TBA). The vibrational spectroscopic data demonstrate the centrosymmetric structure in solid state phase of the 1,3-compound due to non-coincidence between the infrared and Raman bands in the vibrational spectra. The crystal structures were also obtained for Ca2+ and Ba2+ ions with the 1,3-isomer. These salts crystallize in different space groups, also showing very distinct coordination properties and intermolecular interactions. This study provides a sound basis for the future expansion of structural and spectroscopic investigations of this interesting group of metal-ligand compounds as building blocks systems in supramolecular chemistry.
Engineering zwitterionic barrier by squaraine-based porous organic framework fiber for superior lithium-sulfur batteries
Bakenov, Zhumabay,Zhang, Xiaojie,Zhang, Yongguang,Zhao, Jinchen,Zhao, Yan
, (2021/10/04)
The lithium sulfur (Li-S) battery holds great promise in next-generation energy storage technologies. However, the lithium polysulfide (LiPS) shuttle and slow reaction kinetics still limit its commercial development. Here, a squaraine-based porous organic framework (POF) with sulfophilic and lithiophilic moieties was developed as the separator modifications for the first time. The POF coating layer on the common separator builds a strong barrier against the LiPS shuttling, resulting in a robust inhibition on the shuttle effect as well as boosted sulfur reaction kinetics. Therefore, the POF-PP separator demonstrates stable cycling performance with a low capacity attenuation rate of 0.04% over 500 cycles and high areal discharge capacity of 4.67 mAh cm?2 with a sulfur loading of 5 mg cm?2, which show high potential for high loading and practical Li-S battery.
