2941-62-0Relevant academic research and scientific papers
Synthesis and photochemical evaluation of iodinated squarylium cyanine dyes
Santos, Paulo F.,Reis, Lucinda V.,Duarte, Isabel,Serrano, Joao P.,Almeida, Paulo,Oliveira, Anabela S.,Ferreira, Luis F. Vieira
, p. 1135 - 1143 (2005)
Several (multiply) iodinated squarylium cyanine dyes of type 1 and 8 (see Scheme and Table), derived from 1,3-benzothiazole and 6-iodo-1,3-benzothiazole, were synthesized as potential new photosensitizers, with absorptions in the 700-nm region. Their ability to generate singlet oxygen (1O 2) was assessed by luminescence-decay measurement in the near-IR. Some of these new dyes show interesting photophysical properties, and may be potentially used in photodynamic therapy (PDT).
Synthesis and photophysical properties of doubly porphyrin-substituted cyanine dye
Ogawa, Kazuya,Nagatsuka, Yasunori,Kobuke, Yoshiaki
, p. 678 - 685 (2011)
New porphyrin-(cyanine dye) composites, in which two porphyrins are bridged by a cyanine dye through triple bonds, were synthesized. In the UV-vis absorption spectra of the composites, the Soret band and Q-band were red-shifted to 436 and 575640 nm, respectively. The absorption originating from the cyanine dye portion was also red-shifted from 710 nm to 764 nm, suggesting the expansion of πconjugation over the porphyrin and cyanine dye parts. Fluorescence studies suggested that energy transfer from the porphyrin portion to the cyanine dye moiety occurred. The fluorescence intensity decreased with increasing dielectric constants of solvents, suggesting intramolecular photoinduced electron transfer from the porphyrin to the cyanine dye parts. The effective two-photon absorption (2PA) cross-section values were measured using a nanosecond open aperture Z-scan method. The maximum effective 2PA cross-section and two-photon excited fluorescence cross-section values were 33,000 GM and 4,800 GM, respectively, at 860 nm in toluene/pyridine (95:5).
Synthesis and characterization of near-infrared absorbing water soluble squaraines and study of their photodynamic effects in DLA live cells
Shafeekh, Kulathinte M.,Soumya, Mohanannair S.,Rahim, Moochikkadavath A.,Abraham, Annie,Das, Suresh
, p. 585 - 595 (2014)
Here, we report the synthesis, photophysical properties and photodynamic effects in DLA live cells of three water soluble squaraine dyes, viz. bisbenzothiazolium squaraine dyes SQMI and SQDI with iodine in one and both benzothiazolium units, respectively, and an unsymmetrical squaraine dye ASQI containing iodinated benzothiazolium and aniline substituents. The diiodinated SQDI showed an anomalous trend in both fluorescence and triplet quantum yields over the monoiodinated SQMI, with SQDI showing higher fluorescence and lower triplet quantum yields compared to SQMI. Nanosecond laser flash photolysis of SQDI and SQMI indicated the formation of triplet excited states with quantum yield of 0.19 and 0.26, respectively. On photoirradiation, both the SQDI and SQMI generate singlet oxygen and it was observed that both dyes undergoing oxidation reactions with the singlet oxygen generated. ASQI which exhibited a lower triplet quantum yield of 0.06 was, however, stable and did not react with the singlet oxygen generated. In vitro cytotoxicity studies of these dyes in DLA live cells were performed using Trypan blue dye exclusion method and it reflect an order of cytotoxicity of SQDI>SQMI>ASQI. Intracellular generation of the ROS was confirmed by dichlorofluorescein assay after the in vitro PDT. Synthesis, photophysical properties and photodynamic effects in DLA live cells of three water soluble squaraine dyes, SQDI, SQMI and ASQI, are presented. On photoirradiation, both the SQDI and SQMI generate singlet oxygen where both the dyes undergoing oxidation reactions with the singlet oxygen generated, whereas ASQI was stable and did not react with the singlet oxygen. In vitro cytotoxicity studies of these dyes in DLA cells were performed using Trypan blue dye exclusion method and intracellular generation of ROS was confirmed using dichlorofluorescein assay after the in vitro PDT.
A charge transfer type pH responsive fluorescent probe and its intracellular application
Liu, Zhipeng,Zhang, Changli,He, Weijiang,Qian, Fang,Yang, Xiaoliang,Gao, Xiang,Guo, Zijian
, p. 656 - 660 (2010)
A new charge transfer pH fluorescent probe BTP has been prepared by the ethylene bridging of benzothiazole and pyridine. The probe exhibits a specific fluorescent response to pH with a large Stokes shift, and the pH-induced emission enhancement factor (EEF) is about 22-fold when the pH is increased from 3.2 to 5.2. The presence of metal cations such as Na+, K +, Ca2+, Mg2+ and other transition metal cations does not interfere with its fluorescent pH response. In addition, the intracellular pH fluorescent imaging ability of the probe has been confirmed on macrophage cells using a confocal microscope. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.
Design, synthesis and photophysical studies of styryl-based push-pull fluorophores with remarkable solvatofluorochromism
Safir Filho, Mauro,Fiorucci, Sebastien,Martin, Anthony R.,Benhida, Rachid
, p. 13760 - 13772 (2017)
A library of 20 styryl-based push-pull dyes derived from 6-amino substituted benzothiazoles were prepared by an efficient and practical synthetic route from low-cost starting materials. The dyes were firstly designed to present an effective anchoring site for subsequent conjugation. A series of aryl scaffolds, from substituted phenyl rings containing electron donating and withdrawing groups to polycyclic aromatic derivatives, were screened. The inductive effect of N-alkyl substituted benzothiazoles was also explored for three different arrangements. The investigation of the structure-photophysics relationship was performed by UV-vis absorption and steady-state fluorescence emission measurements in solution and by TD-DFT calculations. The dyes presented high brightness, absorption bands in the visible range (～370-453 nm) and large solvatofluorochromism comprising all the visible spectrum, as a consequence of the strong intramolecular charge transfer (ICT) nature of their excited state.
Preparation of novel push-pull benzothiazole derivatives with reverse polarity: Compounds with potential non-linear optic application
Hrobarik, Peter,Sigmundova, Ivica,Zahradnik, Pavol
, p. 600 - 604 (2005)
The hitherto unknown 6-dimethylaminobenzothiazole-2-carbaldehyde was prepared as a starting compound for the synthesis of novel push-pull benzothiazole derivatives with reverse polarity. These compounds are substituted at the 2-position by strong electron-acceptor groups and at the 6-position by NMe2 as strong electron-donor. The new method for synthesis of 6-dimethylaminobenzothiazole involved the successful use of sonochemical reductive methylation. Expected non-linear optical properties of target molecules were studied by EFISH method.
Benzothiazole-Schiff base-Tr*ger's base derivative and preparation method and application thereof
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, (2020/08/02)
The structural general formula of a benzothiazole-Schiff base-base derivative is shown as one of the following formulas, and the preparation method of the benzothiazole-Schiff base-base derivative comprises the following steps: selecting p-bromoaniline, paraformaldehyde, n-butyllithium, p-aminobenzoic acid, substituted o-phenylenediamine, benzothiazole and the like as raw materials, and performingmulti-step reaction to obtain the benzothiazole-Schiff base-base derivative. The product emits yellow green light, the Stokes shift is large, the product has obvious aggregation-induced emission, theexcellent solid-state luminescence performance and good thermal stability, and antifungal performance tests prove that part of the compounds have a good antibacterial effect.
Nickel-Catalyzed Cross-Coupling of Ammonia or Primary Alkylamines with (Hetero)aryl Sulfamates, Carbamates, or Pivalates
MacQueen, Preston M.,Stradiotto, Mark
supporting information, p. 1652 - 1656 (2017/08/11)
A catalyst system capable of effecting the cross-coupling of ammonia or primary alkylamines with (hetero)aryl sulfamates, carbamates, or pivalates is reported for the first time. The air-stable nickel(II) pre-catalyst C1 tolerates a broad spectrum of heterocyclic functionality within both reaction partners, as well as ether, nitrile, pyrrole, trifluoromethyl, and boronate ester substituents. In the case of reactions involving primary alkylamines and (hetero)aryl sulfamates and carbamates, room-temperature cross-couplings were achieved.
Emergence through delicate balance between the steric factor and molecular orientation: a highly bright and photostable DNA marker for real-time monitoring of cell growth dynamics
Gaur, Pankaj,Kumar, Ajay,Dalal, Reena,Bhattacharyya, Shalmoli,Ghosh, Subrata
supporting information, p. 2571 - 2574 (2017/03/09)
Due to its remarkable structural and optical stability in biological milieu, a newly developed small molecule based DNA marker with high brightness (Φ = 0.51, brightness = 26?300 M?1 cm?1) and almost zero toxicity has been explored. For the first time to our knowledge, this approach has provided real-time monitoring of growth and reproductive potency of living cells beyond nine days.
Iron-catalysed, general and operationally simple formal hydrogenation using Fe(OTf)3 and NaBH4
MacNair, Alistair J.,Tran, Ming-Ming,Nelson, Jennifer E.,Sloan, G. Usherwood,Ironmonger, Alan,Thomas, Stephen P.
supporting information, p. 5082 - 5088 (2014/07/08)
An operationally simple and environmentally benign formal hydrogenation protocol has been developed using highly abundant iron(iii) salts and an inexpensive, bench stable, stoichiometric reductant, NaBH4, in ethanol, under ambient conditions. This reaction has been applied to the reduction of terminal alkenes (22 examples, up to 95% yield) and nitro-groups (26 examples, up to 95% yield). Deuterium labelling studies indicate that this reaction proceeds via an ionic rather than radical mechanism.
