scholarly journals Benzo[de]naphtho[1,8-gh]quinolines: synthesis, photophysical studies and nitro explosives detection

2021 ◽  
Vol 8 (4) ◽  
pp. 20218415
Author(s):  
Igor L. Nikonov ◽  
Igor A. Khalymbadzha ◽  
Leila К. Sadieva ◽  
Maria I. Savchuk ◽  
Ekaterina S. Starnovskaya ◽  
...  

A rational synthetic approach to substituted naphtho[1,8-gh]quinolines using intramolecular cyclization in the presence of potassium in the series of (naphthalen-1-yl)isoquinolines is described. The photophysical properties of the obtained compounds were studied; in particular, fluorescence emission was detected in the range 454 - 482 nm with a quantum yield of up to 54%. We also calculated the HOMO-LUMO energies and optimized molecular structures for the resulting fluorophores. Based on the results of fluorescence titration, the Stern-Volmer constants (up to 21587 M-1) and the detection limits of nitroanalytes (up to 1.4 ppm) were calculated, confirming the possibility of their use as potential chemosensors for the visual detection of nitro-containing explosives.

2021 ◽  
Vol 8 (4) ◽  
pp. 20218416
Author(s):  
Igor L. Nikonov ◽  
Leila K. Sadieva ◽  
Мaria I. Savchuk ◽  
Еkaterina S. Starnovskaya ◽  
Dmitry S. Kopchuk ◽  
...  

A rational approach to the synthesis of substituted naphtho[1,8-ef]perimidines based on SNH methodology and cyclization  reaction in the series of condensed azines with naphthalene substituents was presented. Photophysical properties of the obtained fluorophores were studied, in particular, green fluorescence in the 485–536 nm range with quantum yield up to 32.4% was detected. HOMO-LUMO energy values and distributions for the new compounds were calculated by the DFT method in comparison with nitroanalytes and perylene. Based on the data obtained, as well as on the results of fluorescence titration, the possibility of using the new diazaperylenes as potential chemosensors for the visual detection of nitro-containing explosives was shown.


2001 ◽  
Vol 05 (05) ◽  
pp. 460-464 ◽  
Author(s):  
JOHN W. OWENS ◽  
MARSHA ROBINS

This study correlates the photophysical properties of aluminum phthalocyanine tetrasulfonate (AlPcTs), zinc phthalocyanine tetrasulfonate (ZnPcTs), and phthalocyanine tetrasulfonate (PcTs) with their ability to kill human embryonic lung (HEL) cells. Photofrin, a proven anti-cancer drug, was used for comparison. The photophysical properties include fluorescence emission spectra, fluorescence quantum yields, singlet state and radiative lifetimes, quantum yield for triplet formation, and fluorescence rate constants. Results indicate that photodynamic efficacy correlates inversely with fluorescence quantum yield and fluorescence lifetime and directly with quantum yield for triplet formation.


1990 ◽  
Vol 206 ◽  
Author(s):  
R. L. Whetten ◽  
M. M. Alvarez ◽  
S. J. Anz ◽  
K. E. Schriver ◽  
R. D. Beck ◽  
...  

Abstract:A report is given on molecular carbon research in Los Angeles, starting with review of the molecular precursor approach to carbon materials.1 Regarding larger molecules, mixtures of carbon molecules, Cn, are extracted2 in 25–40 percent yield from graphite evaporated under helium. Gram quantities of the mixture are then separated into pure fractions – C60, C70, C76/C78, C84, and higher (n > 88),3,4 and characterized by mass spectrometry, liquid chromatography, and 13CNMR spectroscopy. Examination of the spectroscopic and photophysical5 properties of the molecules, with particular focus on C60 in solution, reveals: (i) the first transitions appear at high energy, are electronically forbidden (in C60, the homo-lumo hu - t1u transitions), and exhibit resolved vibronic structure; (ii) the spectra sharpen in cryogenic media, allowing vibronic assignment; and (iii) relaxation occurs with near-unity quantum yield to a long-lived triplet, which also transfers energy efficiently to acceptors including O2.


RSC Advances ◽  
2020 ◽  
Vol 10 (71) ◽  
pp. 43459-43471
Author(s):  
Hussain A. Z. Sabek ◽  
Ahmed M. M. Alazaly ◽  
Dina Salah ◽  
Hesham S. Abdel-Samad ◽  
Mohamed A. Ismail ◽  
...  

Solvation-dependent photophysical properties of two push–pull thiophene-based compounds with donor–π–acceptor (D–π–A) structures were investigated using absorption, fluorescence emission and time resolved spectroscopy, and supported by different solvation models.


2021 ◽  
Vol 14 (2) ◽  
pp. 138
Author(s):  
Bauyrzhan Myrzakhmetov ◽  
Philippe Arnoux ◽  
Serge Mordon ◽  
Samir Acherar ◽  
Irina Tsoy ◽  
...  

Photodynamic therapy (PDT) is an innovative treatment of malignant or diseased tissues. The effectiveness of PDT depends on light dosimetry, oxygen availability, and properties of the photosensitizer (PS). Depending on the medium, photophysical properties of the PS can change leading to increase or decrease in fluorescence emission and formation of reactive oxygen species (ROS) especially singlet oxygen (1O2). In this study, the influence of solvent polarity, viscosity, concentration, temperature, and pH medium on the photophysical properties of protoporphyrin IX, pyropheophorbide-a, and Photofrin® were investigated by UV-visible absorption, fluorescence emission, singlet oxygen emission, and time-resolved fluorescence spectroscopies.


Biosensors ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 128 ◽  
Author(s):  
Rajkamal Balu ◽  
Robert Knott ◽  
Christopher M. Elvin ◽  
Anita J. Hill ◽  
Namita R. Choudhury ◽  
...  

Herein we report the first example of a facile biomineralization process to produce ultra-small-sized highly fluorescent aqueous dispersions of platinum noble metal quantum clusters (Pt-NMQCs) using a multi-stimulus responsive, biomimetic intrinsically disordered protein (IDP), Rec1-resilin. We demonstrate that Rec1-resilin acts concurrently as the host, reducing agent, and stabilizer of the blue-green fluorescent Pt-NMQCs once they are being formed. The photophysical properties, quantum yield, and fluorescence lifetime measurements of the synthesized Pt-NMQCs were examined using UV-Vis and fluorescence spectroscopy. The oxidation state of the Pt-NMQCs was quantitatively analyzed using X-ray photoelectron spectroscopy. Both a small angle X-ray scattering technique and a modeling approach have been attempted to present a detailed understanding of the structure and conformational dynamics of Rec1-resilin as an IDP during the formation of the Pt-NMQCs. It has been demonstrated that the green fluorescent Pt-NMQCs exhibit a high quantum yield of ~7.0% and a lifetime of ~9.5 ns in aqueous media. The change in photoluminescence properties due to the inter-dot interactions between proximal dots and aggregation of the Pt-NMQCs by evaporation was also measured spectroscopically and discussed.


2012 ◽  
Vol 67 (3) ◽  
pp. 213-218 ◽  
Author(s):  
Bihai Tong ◽  
Jiayan Qiang ◽  
Qunbo Mei ◽  
Hengshan Wang ◽  
Qianfeng Zhang ◽  
...  

Four cationic Ir(III) complexes, [Ir(dpq)2(bpy)]PF6 (1), [Ir(dpq)2(phen)]PF6 (2), [Ir(tfapq)2- (bpy)]PF6 (3), and [Ir(tfapq)2(phen)]PF6 (4) (dpqH = 2,4-diphenylquinoline, tfapqH = 2-(4ʹ-trifluoroacetylphenyl)- 4-phenylquinoline, bpy = 2,2ʹ-bipyridine, phen = 1,10-phenanthroline) have been synthesized and fully characterized. The structure of 4 was also confirmed by single-crystal X-ray diffraction. The electron-acceptor character of the trifluoroacetyl unit leads to a reduced HOMO-LUMO gap and consequently a red-shift of the UV/Vis absorption and luminescence spectra. The solvophobic character of the trifluoroacetyl unit gives rise to a molecule assembly in solution.


2017 ◽  
Vol 41 (18) ◽  
pp. 9826-9839 ◽  
Author(s):  
Boddula Rajamouli ◽  
Rachna Devi ◽  
Abhijeet Mohanty ◽  
Venkata Krishnan ◽  
Sivakumar Vaidyanathan

The red light emitting diode (LED) was fabricated by using europium complexes with InGaN LED (395 nm) and shown digital images, corresponding CIE color coordinates (red region) as well as obtained highest quantum yield of the thin film (78.7%).


2014 ◽  
Vol 18 (08n09) ◽  
pp. 752-761 ◽  
Author(s):  
Tetsuo Okujima ◽  
Yoichi Shida ◽  
Keishi Ohara ◽  
Yuya Tomimori ◽  
Motoyoshi Nishioka ◽  
...  

A series of O-chelated BODIPYs fused with aromatic rings such as benzene and acenaphthylene at β,β-positions was synthesized as a near-infrared dye. The photophysical properties were examined by UV-vis-NIR absorption and fluorescence measurement. Acenaphthylene-fused O-BODIPYs showed a intense absorption at 750–840 nm with the ε of 105 M-1.cm-1. and a fluorescence emission at 770–850 nm with the high Φ value of 0.06–0.43.


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