absorption and fluorescence spectroscopy
Recently Published Documents


TOTAL DOCUMENTS

139
(FIVE YEARS 12)

H-INDEX

24
(FIVE YEARS 1)

2021 ◽  
Vol 55 (2 (255)) ◽  
pp. 151-157
Author(s):  
Mariam A. Shahinyan ◽  
Zvart H. Movsisyan ◽  
Gohar G. Hovhannisyan ◽  
Poghos H. Vardevanyan

The interaction of methylene blue (MB) and acridine orange (AO) with poly(rA)-poly(rU) was studied using absorption and fluorescence spectroscopy methods. The absorption and fluorescence spectra of complexes of these ligands with a polynucleotide were obtained, similar to those of complexes of these ligands with double-stranded (ds-) DNA. It was revealed that the isosbestic point in the spectra of the AO-poly(rA)-poly(rU) and MB-poly(rA)-poly(rU) complexes is not formed, although the binding of AO and MB with ds-RNA by intercalation mode is not excluded.


Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3305
Author(s):  
Tim Lippold ◽  
Jörg M. Neudörfl ◽  
Axel Griesbeck

A synthetic route to new heterocyclic 1,1-donor–acceptor-substituted alkenes starting with N-methyl-acridone, xanthone, and thioxanthone was investigated, leading to the acridone- and xanthone-derived products methyl 2-methoxy-2-(10-methylacridin-9 (10H)-ylidene)acetate (7) and methyl 2-methoxy-2-(9H-xanthen-9-ylidene)acetate (10) in low yields with the de-methoxylated product methyl 2-(10-methylacridin-9 (10H)-ylidene)acetate (8) and the reduced compound methyl 2-methoxy-2-(9H-xanthen-9-yl)acetate (11) as the major products from N-methyl acridone and xanthone. From thioxanthone, only the rearrangement and reduction products (14) and (15) resulted. The photophysical properties of compounds (7), (8), and (10) were investigated in the presence and absence of the Brønsted acid TFA by NMR, UV–VIS absorption, and fluorescence spectroscopy. Protonation of the acridone-derived alkenes (7) and (8) led to strong bathochromic and hyperchromic fluorescence shifts and a substantial increase in Stokes shift. The photooxygenation experiments with these substrates showed an unusual reactivity pattern in the singlet oxygen processes: whereas the electron-rich enolether (7) was chemically unreactive, (8) and (10) were oxidatively cleaved, presumably via intermediate 1,2-dioxetanes.


Sensors ◽  
2020 ◽  
Vol 20 (10) ◽  
pp. 2973
Author(s):  
Aikohi Ugboya ◽  
Khristal Monroe ◽  
Unodinma Ofulue ◽  
Kayley Yates ◽  
Debanjana Ghosh ◽  
...  

Polymeric chemosensors are vital sensing tools because of higher sensitivity compared to their monomeric counterparts and tunable mechanical properties. This study focuses on the incorporation of a hydroxyaromatic 1,2,3-triazole sensor, 2-(4-phenyl 1H-1,2,3-triazol-1-yl)phenol (PTP), into polymers. By itself, the triazole has a selective, fluorometric response to the fluoride, acetate, and dihydrogen phosphate anions, and is most responsive to fluoride. Current investigations probe the suitability of various polymeric backbones for the retention and enhancement of the triazole’s sensing capabilities. Backbones derived from acrylic acid, methyl methacrylate, divinylbenzene, and styrene were explored. UV-illumination, Nuclear Magnetic Resonance (NMR) titration, and ultraviolet-visible (UV-Vis) absorption and fluorescence spectroscopy studies are used to investigate the performance of newly synthesized polymers and the derivatives of PTP that serve as the polymers’ precursors. Among the polymers investigated, copolymers with styrene proved best; these systems retained the sensing capabilities and were amenable to tuning for sensitivity.


2020 ◽  
Vol 44 (39) ◽  
pp. 17112-17121
Author(s):  
Mohammad Dodangeh ◽  
Ivo Grabchev ◽  
Kamaladin Gharanjig ◽  
Desislava Staneva ◽  
Ren-Cheng Tang ◽  
...  

 Six recently synthesised PAMAM dendrimers from zero, first and second generations curcumin and 2,4-dihydroxybenzophenone have been investigated in water/dioxane (4 : 1) (v/v) solution by absorption and fluorescence spectroscopy in order to determine their photostability.


MRS Advances ◽  
2020 ◽  
Vol 5 (62) ◽  
pp. 3215-3225
Author(s):  
Pasquale Porcu ◽  
Andrea García-Rodriguez ◽  
Juan Carlos Carranza-Cruz ◽  
Javier Illescas ◽  
Ernesto Rivera

AbstractA novel series of copolymers were obtained from the copolymerization of 1-ethynylpyrene (EP) (known as pyrenylacetylene) and ethynylbenzene (EB) (named also phenylacetylene) with WCl6 as catalyst and toluene as solvent, using different monomer molar ratios EP/EB (80:20, 60:40, 50:50; 40:60, 20:80). The optical properties of the obtained copolymers Poly(EP-co-EB) were determined by absorption and fluorescence spectroscopy. Absorption spectra of the copolymers Poly(EP-co-EB) showed that copolymers containing phenylacetylene units possess a lower degree of conjugation than the homopolymer trans-poly(1-ethynylpyrene) (trans-PEP), since they showed a twisted conformation. These results were confirmed by emission spectroscopy showing the formation of excimers for those copolymers containing high pyrene content.


Sign in / Sign up

Export Citation Format

Share Document