19654-19-4Relevant articles and documents
Synthesis, photophysics, and reverse saturable absorption of platinum complexes bearing extended π-conjugated C^N^N ligands
Li, Zhongjing,Sun, Wenfang
, p. 14021 - 14029 (2013)
The synthesis of ligands 1-L-6-L that feature the 6-[9,9-di(2-ethylhexyl)- 7-R-9H-fluoren-2-yl]-2,2′-bipyridine (C^N^N) core (R = 4-R′-phenylethynyl with R′ = NO2, benzothiazol-2-yl (BTZ), H and OCH3 or R = 4′-BTZ-phenyl or BTZ) and their platinum complexes 1-6 were reported in this paper. The photophysical properties of these ligands and the Pt(ii) complexes, including the UV-vis absorption spectra, emission characteristics at room temperature and at 77 K, and the triplet transient difference absorption spectra, were systematically investigated in order to understand the effects of the substituent at the 4-position of the 1-ethynylphenyl component and the extension of π-conjugation between the C^N^N core and the BTZ substituent. Reverse saturable absorption (RSA) of complexes 1-6 was demonstrated at 532 nm using 4.1 ns laser pulses. The UV-vis absorption spectra of 1-L-6-L are featured by strong 1π,π* transitions in the blue spectral region, and the absorption bands are effectively red-shifted by substitution at the 4-position of the ethynylphenyl motif and by the extended π-conjugation of the linkage. A similar effect was observed for the fluorescence spectra of these ligands in CH2Cl2 at room temperature, but the nature of the fluorescence varies from 1π,π* fluorescence in 3-L and 6-L, to intraligand charge transfer (1ILCT) fluorescence in 1-L, 2-L and 5-L; while 4-L possesses mixed 1π,π*/ 1ILCT characters. All ligands exhibit moderate triplet transient absorption (TA) in the visible spectral region, with substitution at the 4-position of the ethynylphenyl component broadening of the TA bands, while extended π-conjugation of the linkage inducing red-shifts of the TA bands. For Pt(ii) complexes 1-6, their UV-vis absorption spectra constitute red-shifted 1π,π* transitions and low-energy metal-to-ligand charge transfer (1MLCT/1ILCT) tails. The emission of these complexes at room temperature in CH2Cl2 predominantly originates from the C^N^N core localized 3π,π* state, probably mixed with minor 3MLCT character. 4-Position substitution and extended π-conjugation on the ligands exert a negligible effect on the shape and energy of the emission spectra. Similar to their respective ligands, 1-6 all exhibit broader and red-shifted TA spectra with respect to their ligands and both the 4-position substitution and extended π-conjugation bathochromically shift the TA band maxima. The nonlinear transmission experiments carried out for 1-6 at 532 nm reveal that all complexes exhibit strong reverse saturable absorption (RSA), and the degree of RSA follows this trend: 6 2 and BTZ) and by extending the π-conjugation; while electron-donating substituent (OCH 3 in 4) decreases the RSA at 532 nm.
Mechanochromism and aggregation induced emission in benzothiazole substituted tetraphenylethylenes: A structure function correlation
Jadhav, Thaksen,Dhokale, Bhausaheb,Mobin, Shaikh M.,Misra, Rajneesh
, p. 29878 - 29884 (2015)
The donor-acceptor benzothiazole substituted tetraphenylethylenes (BT-TPEs) 3a-3c were designed and synthesized to examine the effect of the linkage between the BT and the TPE unit on the photophysical, aggregation induced emission (AIE) and mechanochromi
Ultrasound-assisted efficient and green synthesis of 2-substituted benzothiazoles under solvent-free condition using recyclable sulfated tungstate
Pise, Ashok S.,Ingale, Ajit P.,Dalvi, Navnath R.
supporting information, p. 3629 - 3641 (2021/10/12)
Sulfated tungstate catalyzed an efficient and ecofriendly protocol has been described for the synthesis of 2-substituted benzothiazoles. The corresponding benzothiazoles were obtained using a condensation reaction of 2-aminothiophenol with various aldehydes under ultrasound irradiation at room temperature. Various functional groups on the 2-aminothiophenol as well as on the aldehydes were tolerated to provide 2-substituted benzothiazoles derivatives in excellent yields. The faster reaction rate, solvent-free or mild reaction conditions, wide functional group compatibility, excellent yields, easy work-up procedure, and excellent catalyst recyclability are the advantages of this protocol. These advantages make this process more practicable, cost-effective, and environmentally benign.
Fast and high-efficiency synthesis of 2-substituted benzothiazoles via combining enzyme catalysis and photoredox catalysis in one-pot
Yang, Zeng-Jie,Gong, Qing-Tian,Yu, Yuan,Lu, Wei-Fan,Wu, Zhe-Ning,Wang, Na,Yu, Xiao-Qi
supporting information, (2021/01/14)
An efficient and green method, combining enzymatic and visible-light catalysis for synthesis of the widely applicable 2-substituted benzothiazoles, has been developed. This method features a relay catalysis protocol consisting of biocatalytic promiscuity
A TEMPO-Functionalized Ordered Mesoporous Polymer as a Highly Active and Reusable Organocatalyst
Guo, Ying,Wang, Wei David,Li, Shengyu,Zhu, Yin,Wang, Xiaoyu,Liu, Xiao,Zhang, Yuan
supporting information, p. 3689 - 3694 (2021/09/29)
The properties of high stability, periodic porosity, and tunable nature of ordered mesoporous polymers make these materials ideal catalytic nanoreactors. However, their application in organocatalysis has been rarely explored. We report herein for the first time the incorporation of a versatile organocatalyst, 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO), into the pores of an FDU-type mesoporous polymer via a pore surface engineering strategy. The resulting FDU-15-TEMPO possesses a highly ordered mesoporous organic framework and enhanced stability, and shows excellent catalytic activity in the selective oxidation of alcohols and aerobic oxidative synthesis of 2-substituted benzoxazoles, benzimidazoles and benzothiazoles. Moreover, the catalyst can be easily recovered and reused for up to 7 consecutive cycles.
