scholarly journals New 2,5-bis(2-ethylhexyl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione-2,2’-bipyridine-based co-polymer, synthesis, photophysical properties and response to metal cations

2021 ◽  
Vol 8 (4) ◽  
pp. 20218417
Author(s):  
Alexey P. Krinochkin ◽  
Мaria I. Savchuk ◽  
Еkaterina S. Starnovskaya ◽  
Igor L. Nikonov ◽  
Artem V. Baklykov ◽  
...  
Keyword(s):  
Photophysical Properties ◽  
Bathochromic Shift ◽  
Metal Cations ◽  
Polymer Synthesis ◽  
Sonogashira Reaction ◽  
Absorption And Emission

A new co-polymer based on fragments of 2-(2-pyridyl)monoazatriphenylene and 2,5-bis (2-ethylhexyl)-3,6-di(thiophen-2-yl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione was prepared by using the Sonogashira reaction. The photophysical properties of the polymer were studied. The presence of a strong bathochromic shift of the absorption and emission maxima in comparison with the previously described monomer units is shown. The polymer exhibits an intense “turn-off” response toward Cu2+ cations.

scholarly journals Fluorinated azobenzenes as supramolecular halogen-bonding building blocks

2019 ◽  
Vol 15 ◽  
pp. 2013-2019 ◽  
Author(s):  
Esther Nieland ◽  
Oliver Weingart ◽  
Bernd M Schmidt
Keyword(s):  
Solid State ◽  
Dft Calculations ◽  
Visible Light ◽  
Half Life ◽  
Photophysical Properties ◽  
Bathochromic Shift ◽  
Halogen Bonding ◽  
Building Blocks ◽  
Partial Overlap

ortho-Fluoroazobenzenes are a remarkable example of bistable photoswitches, addressable by visible light. Symmetrical, highly fluorinated azobenzenes bearing an iodine substituent in para-position were shown to be suitable supramolecular building blocks both in solution and in the solid state in combination with neutral halogen bonding acceptors, such as lutidines. Therefore, we investigate the photochemistry of a series of azobenzene photoswitches. Upon introduction of iodoethynyl groups, the halogen bonding donor properties are significantly strengthened in solution. However, the bathochromic shift of the π→π* band leads to a partial overlap with the n→π* band, making it slightly more difficult to address. The introduction of iodine substituents is furthermore accompanied with a diminishing thermal half-life. A series of three azobenzenes with different halogen bonding donor properties are discussed in relation to their changing photophysical properties, rationalized by DFT calculations.

Effect of substituents on absorption and fluorescence properties of pyrazolo[3,4-b]pyrrolo[2,3-d]pyridines

2008 ◽  
Vol 86 (11) ◽  
pp. 1070-1076 ◽  
Author(s):  
Bhausaheb K Ghotekar ◽  
Muddassar A Kazi ◽  
Madhukar N Jachak ◽  
Raghunath B Toche
Keyword(s):  
Good Yield ◽  
Substituent Effect ◽  
Photophysical Properties ◽  
Fluorescence Properties ◽  
Absorption And Emission ◽  
Effect Of Substituents ◽  
Convenient Route

A convenient route was successfully developed for the synthesis of novel heterocycles such as pyrazolo[3,4-b]pyrrolo[2,3-d]pyridines (PPP) from pyrazolo[3,4-b]pyridines in good yield. The PPP derivatives synthesized were further studied for their photophysical properties, and it was observed that absorption and emission λmax changed, owing to the substituent effect at 4 positions. These compounds were obtained from highly reactive starting materials, 5-aminopyrazoles and α-acetyl γ-butyrolactone.Key words: α-acetyl γ-butyrolactone, pyrazolo[3,4-b]pyrrolo[2,3-d] pyridine, absorption, emission, fluorescence.

scholarly journals Unsymmetrically functionalized 5,5″-diaryl- and 5,6,5″-triaryl-2,2′:6′,2″-terpyridines: an efficient synthetic route and photophysical properties

2017 ◽  
Vol 95 (8) ◽  
pp. 851-857 ◽  
Author(s):  
Alexey P. Krinochkin ◽  
Dmitry S. Kopchuk ◽  
Albert F. Khasanov ◽  
Nikolay V. Chepchugov ◽  
Igor S. Kovalev ◽  
...  
Keyword(s):  
Organic Solvents ◽  
Photophysical Properties ◽  
Emission Spectra ◽  
Side Chain ◽  
Synthetic Route ◽  
Absorption And Emission ◽  
Efficient Approach ◽  
Absorption And Emission Spectra ◽  
Acetonitrile Solutions ◽  
Intense Emission

An efficient approach for the synthesis of 5,5″- or 5,6,5″-aryl substituted 2,2′:6′,2″-terpyridines, bearing an anneleted cyclopentene unit in one of the side-chain pyridine rings for the improved solubility in organic solvents, via their 1,2,4-triazine analogues has been developed. By using this approach, various aromatic substituents were introduced in the 2,2′:6′,2″-terpyridine core. Depending on the nature of the aromatic substituents, the obtained terpyridines exhibited an intense emission in a range of ca. 344–394 nm in acetonitrile solutions. For the most representative compounds, pronounced bathochromic shifts in both absorption and emission spectra were observed compared with previously reported substituted terpyridines.

scholarly journals Synthesis, photophysical properties and photodynamic antimicrobial activity of meso 5,10,15,20-tetra(pyren-1-yl)porphyrin and its indium(III) complex

2021 ◽  
pp. A-F
Author(s):  
Jackline Khisa ◽  
Solomon Derese ◽  
John Mack ◽  
Edith Amuhaya ◽  
Tebello Nyokong
Keyword(s):  
Mass Spectrometry ◽  
Antimicrobial Activity ◽  
Fluorescence Quantum Yield ◽  
Photophysical Properties ◽  
Bathochromic Shift ◽  
Intersystem Crossing ◽  
Free Base ◽  
H Nmr ◽  
Solvent Systems ◽  
Dose Dependent

In this study, free-base meso 5,10,15,20-tetra(pyren-1-yl)porphyrin (H2TPyP) and its corresponding indium(III) complex (InClTPyP) were synthesized and characterized on the basis of mass spectrometry, 1H NMR spectroscopy and elemental analysis. InClTPyP was obtained in good yield by treating the free base H2TPyP with indium(III) chloride. Purification of these compounds was achieved through column chromatography using different solvent systems. Metallation of the free base to form a metallo-porphyrin afforded improved photophysical properties. There was a bathochromic shift in wavelength of absorption from the parent free base H2TPyP ([Formula: see text] = 431 nm) to metallated indium(III) complex ([Formula: see text] = 443 nm). The fluorescence quantum yield in H2TPyP was higher ([Formula: see text] = 0.131) than in InClTPyP ([Formula: see text] = 0.017) due to efficient intersystem crossing to the triplet manifold in the metallated porphyrin. Upon illumination, both H2TPyP and InClTPyP show effective dose dependent antimicrobial activity against Staphylococcus aureus with photoinactivation IC[Formula: see text] values of 27.89 and 16.67 [Formula: see text]M, respectively.

scholarly journals Tritolylporphyrin dimer as a new potent hydrophobic sensitizer for photodynamic therapy of melanoma.

2001 ◽  
Vol 48 (1) ◽  
pp. 277-282 ◽  
Author(s):  
A Drzewiecka ◽  
K Urbańska ◽  
Z Matuszak ◽  
M Pineiro ◽  
L G Arnaut ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Quantum Yield ◽  
Singlet Oxygen ◽  
Biological Effect ◽  
Photophysical Properties ◽  
Red Light ◽  
Human Melanoma ◽  
Oxygen Production ◽  
Absorption And Emission ◽  
Emission Properties

We report the synthesis, photochemical and photophysical properties and preliminary studies on biological effect of a new tritolylporphyrin dimer (T-D). Absorption and emission properties of T-D suggest its possible use in photodynamic therapy. T-D is capable of singlet oxygen production with 0.8 quantum yield. It also has a high photostability. The photodynamic properties of the dimer were examined following the growth of SKMEL 188 (human melanoma) cells irradiated with red light (cut off < 630 nm). The surviving fraction of the cells decreased about 3-fold (vs. non-irradiated cells) for an 81 J/cm dose. Our results suggest that tritolylporphyrine dimer T-D may be an interesting hydrophobic sensitizer for photodynamic therapy.

scholarly journals Photophysical characterization of 3-acyl-4-quinolones

2020 ◽  
Author(s):  
Karine N. de Andrade ◽  
Amanda R. P. Costa ◽  
Rodolfo I. Teixeira ◽  
Micaeli L. da S. Moreira ◽  
José Walkimar M. Carneiro ◽  
...  
Keyword(s):  
Experimental Data ◽  
Acidic Medium ◽  
Photophysical Properties ◽  
Bathochromic Shift ◽  
Fluorescent Properties ◽  
Polarization Model ◽  
Emission Profile ◽  
Aromatic Character ◽  
Intramolecular Hydrogen ◽  
Homo Lumo

4-quinolones derivatives can present fluorescent properties, depending on their substituents and on the chemical environment (e.g., acidic medium), allowing their application as ion sensors. We theoretically evaluated the photophysical properties of previously synthesized 3-acyl-4-quinolones to verify how different substituents (R1=H, NH2 and R2 = OEt, OH, NHPh) affect their absorption profiles and the emission profile of a reference compound, PB3. All DFT and TD-DFT calculations were performed at B3LYP-D3/6-311++G(d,p) level and continuum polarization model for simulated acetonitrile as solvent. For PB2 (R1 = H, R2 = OEt), we observed hypsochromic shift compared to PB3 due to the increase of the gap between HOMO/LUMO (absence of electron-donating group), in accordance with experimental data. For R1=NH2 and R2=OH, NHPh (PB6 and PB10, respectively), the gap between HOMO/LUMO increases, resulting in a soft bathochromic shift for the simulated absorption spectra. In addition, we evaluated the effect of acid addition on the absorption and emission profile of PB3 and the results were compared with experimental data. Our thermodynamic results suggest that protonation occurs on the endocyclic carbonyl of the quinolone moiety, probably due to an increased aromatic character, as suggested by our NICS calculations. Finally, we associate the increase of the fluorescence in the acidic medium to the establishment of an intramolecular hydrogen bond and, thus, increased rigidity.

scholarly journals Syntheses and Characterizations of Platinum Complexes with New Pyrene-based Salicylaldiminato-type Ligand Substituted at 7-Position of Pyrene

2021 ◽  
Vol 10 (2) ◽  
pp. 26-35
Author(s):  
Dien Luong Xuan
Keyword(s):  
Photophysical Properties ◽  
Emission Spectra ◽  
Platinum Complexes ◽  
X Ray Diffraction ◽  
Absorption And Emission ◽  
Absorption And Emission Spectra ◽  
Tert Butyl ◽  
Imine Group ◽  
Butyl Group ◽  
Tert Butyl Group

Many experimental data show that bulky substituents on the molecules enhance solubility, catalytic activity, and photophysical properties due to the prevention of π-π stacking in metal salicylaldimines. In order to understand the effect of bulkiness of substituents on the properties of the obtained molecules, the author researched and synthesized two new pyrene-based salicylaldiminato-type ligands that were substituted at 7-position and functionalized on imine group with bulky substituents. After the introduction of  the tert-butyl group at 7-position of pyrene by Friedel-Crafts reaction, the syntheses of new ligands 1-hydroxy-2-[((2,6-dimethylphenyl)-imino)methyl]-7-(tert-butyl)-pyrene 3, 2-hydroxy-1- [((2,6-dimethylphenyl)imino)methyl]-7-(tert-butyl)-pyrene 4 and corresponding platinum complexes 3(Pt), 4(Pt) were performed in the different ways with the synthetic processes of the complexes 1(Pt) and 2(Pt). The new ligands and complexes were characterized by 1H NMR, IR spectroscopy, mass spectroscopy, elemental analysis and X-ray diffraction, only for 3(Pt). In addition to measurements of the absorption and emission spectra, TDDFT calculations using the B3LYP functions were also performed. The complexes 3(Pt) and 4(Pt) exhibit good solubility and red-shift in absorption and emission spectra because of tert-butyl group at 7-position of pyrene and extension of the delocalized π-orbitals to the 2,6-dimethylphenyl on imine group. The change of functional groups also induces the upfield shift of the protons affected by ring currents of phenyl groups Ar-3, Ar-4 on imine groups. Introduction of t-butyl groups in pyrene moieties can stabilize radical forms in oxidation processes.

scholarly journals Styryl-based new organic chromophores bearing free amino and azomethine groups: synthesis, photophysical, NLO, and thermal properties

2020 ◽  
Vol 16 ◽  
pp. 2282-2296
Author(s):  
Anka Utama Putra ◽  
Deniz Çakmaz ◽  
Nurgül Seferoğlu ◽  
Alberto Barsella ◽  
Zeynel Seferoğlu
Keyword(s):  
Schiff Base ◽  
Schiff Bases ◽  
Free Amino ◽  
Second Harmonic ◽  
Photophysical Properties ◽  
Bathochromic Shift ◽  
Visible Region ◽  
Amino Derivative ◽  
Quantum Yields ◽  
Thermal Stabilities

Herein we report the synthesis and characterization of a new series of styryl-based push-pull dyes containing a free amino group and their Schiff base derivatives. The dyes include the dicyanomethylene group as an acceptor and different para-substituted alkylamines as donors. Morever as a proton-sensitive group a pyridin-2-yl substituent was attached to the para-position of the phenyl moiety in both series of compounds. The photophysical properties of the dyes were examined in various solvents with different polarities and showed absorption in the visible region and green-red emission with low quantum yields. The absorption and the emission maxima were shifted bathocromically by increasing the solvent’s polarity. However, there was no correlation with the polarity parameters of the solvents. The pH-sensitive properties of all prepared Schiff bases were examined against TBAOH in DMSO, via deprotonation of the OH group in the salicylidene moiety and their reverse protonation was also investigated using TFA. The Schiff bases exhibited a bathochromic shift upon the addition of TBAOH to their solutions in DMSO. Therefore, they showed potential to be utilized as colorimetric and luminescence pH sensors. The second-order nonlinear optical (NLO) responses of the dyes were measured by the electric field-induced second harmonic (EFISH) generation method. The highest μβ values were obtained for the dyes bearing the julolidine donor as 1430 × 10−48 esu (for free amino derivative) and 1950 × 10−48 esu (for Schiff base derivative), respectively. The structural and electronic properties of the dyes as well as their NLO properties were further studied using DFT calculations. The thermal stabilities of all dyes were evaluated by thermogravimetric analysis (TGA). The TGA data showed that all dyes were thermally stable up to 250 °C.

On the photophysical properties of IrIII, PtII, and PdII (phenylpyrazole) (phenyldipyrrin) complexes

2020 ◽  
Vol 22 (6) ◽  
pp. 3217-3233 ◽  
Author(s):  
Jelena Föller ◽  
Daniel H. Friese ◽  
Stefan Riese ◽  
Jeremy M. Kaminski ◽  
Simon Metz ◽  
...  
Keyword(s):  
Photophysical Properties ◽  
Emission Characteristics ◽  
Absorption And Emission ◽  
Theory And Experiment

The absorption and emission characteristics of (ppz)2(dipy)IrIII, (ppz)(dipy)PtII and (ppz)(dipy)PdII, where ppz stands for a phenylpyrazole and dipy for a phenyl meso-substituted dipyrrin ligand, have been investigated by theory and experiment.

Novel Cyclometalated Iridium(III) Xanthate Complexes and Their Phosphorescence Behavior in the Presence of Metal Ions

2012 ◽  
Vol 67 (9) ◽  
pp. 865-871
Author(s):  
Bihai Tong ◽  
Yaqing Xu ◽  
Jiayan Qiang ◽  
Man Zhang ◽  
Qunbo Mei ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Metal Ions ◽  
Single Crystal ◽  
Photophysical Properties ◽  
Metal Cations ◽  
X Ray Diffraction ◽  
Red Emission ◽  
X Ray ◽  
Emission Lifetime ◽  
Phosphorescence Quantum Yield

Two cyclometalated iridium(III) complexes, Ir(dpppz)(ppz)(ipx) and Ir(ppz)2(ipx) (dpppzH=1- (2,6-dimethylphenoxy)-4-phenylphthalazine, ppzH=4-phenylphthalazinone, ipx=isopropyl xanthate), have been synthesized and characterized by single-crystal X-ray diffraction. The photophysical properties of the two complexes were also investigated. Ir(dpppz)(ppz)(ipx) shows orange-red emission at around 606 nm with a phosphorescence quantum yield of ca. 0.0032 and an emission lifetime of 188 ns, while Ir(ppz)2(ipx) shows orange-red emission at around 599 nm with a phosphorescence quantum yield of ca. 0.00318 and an emission lifetime of 259 ns. The phosphorescence behavior of Ir(ppz)2(ipx) towards different metal cations has also be studied. Its strong phosphorescence is quenched by Hg2+, Cu2+ and Ag+ cations. The interaction ratio with Hg2+ is 1:1

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