NLO chromophores containing dihydrobenzothiazolylidene and dihydroquinolinylidene donors with an azo linker: Synthesis and optical properties
摘要:
We report the synthesis of a series of nonlinear optical chromophores containing either - a dihydrobenzothiazolylidene or dihydroquinolinylidene donor with an azo linker. The results demonstrate the versatility of coupling a diazonium salt to a donor-methylidene nucleus in order to access novel materials with good thermal stabilities and high nonlinear optical responses. From hyper-Raleigh scattering studies it was found that the use of the well-known TCF acceptor yields the best performing chromophores, one of which has a dynamic first hyperpolarizability of 1900 x 10(-30) esu at 800 nm. The results from this study suggest the use of pro-aromatic donors such as dihydrobenzothiazolylidene or dihydroquinolinylidene results in compounds with higher nonlinear optical responses than those containing donors based on either indoline or aniline. (C) 2013 Elsevier Ltd. All rights reserved.
The synthesis and spectroscopic characterisation of some representative N-alkyl-substituted quaternaryammoniumsalts derived from benzothiazole, benzoxazole, benzo-selenazole, indole and quinoline are described. These heterocyclic salts, bearing an activated methyl group in the 2-position in relation to the nitrogen atom and N-methyl, -pentyl, -hexyl and -decyl chains, are typical precursors of cyanine
Acridinium‐conjugated aromatic heterocycles as highly potent FtsZ inhibitors: Design, synthesis, and biological evaluation
作者:Di Song、Nan Zhang、Yangchun Ma、Shenyan Zhang、Weijin Chen、Ting Guo、Shutao Ma
DOI:10.1002/ardp.202100400
日期:2022.6
newly synthesized compounds proved to be substrates of the Escherichia coli efflux pump AcrB, thus affecting the activity. Their structure–activity relationships were summarized in detail. The most potent compound 10f quickly eliminated bacteria in a bactericidal mode, with low susceptibility to induce bacterial resistance. Further mechanistic studies with the BsFtsZ protein revealed that 10f functioned
An Insight into Symmetrical Cyanine Dyes as Promising Selective Antiproliferative Agents in Caco-2 Colorectal Cancer Cells
作者:João L. Serrano、Ana Maia、Adriana O. Santos、Eurico Lima、Lucinda V. Reis、Maria J. Nunes、Renato E. F. Boto、Samuel Silvestre、Paulo Almeida
DOI:10.3390/molecules27185779
日期:——
Several cytotoxic approaches have been used over the years to overcome this public health threat, such as chemotherapy, radiotherapy, and photodynamic therapy (PDT). Cyaninedyes are a class of compounds that have been extensively studied as PDT sensitisers; nevertheless, their antiproliferative potential in the absence of a light source has been scarcely explored. Herein, the synthesis of eighteen symmetric
NMR spectroscopy study of 2-methylbenzoxazolium salts hydroxylation in DMSO-d6 solution
作者:Ricardo Santos、Luís M. Fernandes、Renato F. Boto、Rogério Simões、Paulo Almeida
DOI:10.1016/j.tetlet.2006.07.091
日期:2006.9
2-Methylbenzoxazolium salts showed an unexpected transformation at room temperature, promoted by residual water present in dimethyl sulfoxide. This transformation was followed up inside of an NMR sample tube using DMSO-d(6) as solvent, in a series of representative quaternary ammonium salts with carboxymethyl, ethyl, pentyl and decyl N-alkyl chains, resulting in an exclusive product. The corresponding benzothiazolium and benzoselenazolium salts presented a si similar behavior after heating at a temperature of 50 degrees C with the addition of one drop of D2O for the first of these two salts. This reaction could play a very important role in explaining certain secondary reactions occurring in the preparation of compounds where these salts are precursors, classically in cyanine dye synthesis. Four new benzoxazolols were characterized by NMR spectroscopy and HR FAB-MS. (c) 2006 Elsevier Ltd. All rights reserved.