scholarly journals Thiophene-forming one-pot synthesis of three thienyl-bridged oligophenothiazines and their electronic properties

2016 ◽  
Vol 12 ◽  
pp. 2055-2064 ◽  
Author(s):  
Dominik Urselmann ◽  
Konstantin Deilhof ◽  
Bernhard Mayer ◽  
Thomas J J Müller
Keyword(s):  
Cyclic Voltammetry ◽  
Helical Structure ◽  
Quantum Yields ◽  
Absorption Bands ◽  
One Pot ◽  
Fluorescence Quantum Yields ◽  
Oxidation Potentials ◽  
Td Dft ◽  
Lower Oxidation ◽  
Stokes Shifts

The pseudo five-component Sonogashira–Glaser cyclization synthesis of symmetrically 2,5-diaryl-substituted thiophenes is excellently suited to access thienyl-bridged oligophenothiazines in a one-pot fashion. Three thienyl-bridged systems were intensively studied by UV–vis and fluorescence spectroscopy as well as by cyclic voltammetry. The oxidation proceeds with lower oxidation potentials and consistently reversible oxidations can be identified. The Stokes shifts are large and substantial fluorescence quantum yields can be measured. Computational chemistry indicates lowest energy conformers with sigmoidal and helical structure, similar to oligophenothiazines. TD-DFT and even semiempirical ZINDO calculations reproduce the trends of longest wavelengths absorption bands and allow the assignment of these transitions to possess largely charge-transfer character from the adjacent phenothiazinyl moieties to the central thienyl unit.

Chlorination vs. fluorination: a study of halogenated benzo[c][1,2,5]thiadiazole-based organic semiconducting dots for near-infrared cellular imaging

2020 ◽  
Vol 44 (19) ◽  
pp. 7740-7748
Author(s):  
Daize Mo ◽  
Li Lin ◽  
Pengjie Chao ◽  
Hanjian Lai ◽  
Qingwen Zhang ◽  
...  
Keyword(s):  
Near Infrared ◽  
Cellular Imaging ◽  
Quantum Yields ◽  
Fluorescence Quantum Yields ◽  
Stokes Shifts

The chlorinated dots based on chlorinated benzo[c][1,2,5]thiadiazole unit possess higher fluorescence quantum yields, larger Stokes shifts, and better photostability than the fluorinated dots.

Synthesis and Photophysical Properties of 3-(Trifluoromethyl)-2H-imidazo[5,1-a]isoquinolinium Chloride Derivatives

Synlett ◽  
2017 ◽  
Vol 29 (03) ◽  
pp. 296-300 ◽  
Author(s):  
Ali Darehkordi ◽  
Fariba Rahmani ◽  
Mahin Ramezani ◽  
Alireza Bazmandegan-Shamili
Keyword(s):  
Blue Light ◽  
Uv Radiation ◽  
Photophysical Properties ◽  
Molecular Probes ◽  
Quantum Yields ◽  
Light Emitting ◽  
Fluorescence Studies ◽  
Fluorescence Quantum Yields ◽  
Fluorescent Molecular Probes ◽  
Stokes Shifts

A series of novel blue-light-emitting 2H-imidazo[5,1-a]isoquinolinium chloride derivatives were synthesized by the reaction of isoquinoline with trifluoroacetimidoyl chlorides and isocyanides in dry CH2Cl2 in excellent yields. Fluorescence studies showed that the compounds absorb UV radiation and then emit blue light at about 481 nm with moderate to good fluorescence quantum yields. These compounds also showed high Stokes shifts, and can be used to develop ­ultrasensitive fluorescent molecular probes to study a variety of biological events and processes.

FLUORESCENCE QUANTUM YIELDS OF 124-kDa PHYTOCHROME FROM OAT UPON EXCITATION WITHIN DIFFERENT ABSORPTION BANDS

1990 ◽  
Vol 52 (1) ◽  
pp. 19-22 ◽  
Author(s):  
Claudio G. Colombano ◽  
Silvia E. Braslavsky ◽  
Alfred R. Holzwarth ◽  
Kurt Schaffner
Keyword(s):  
Quantum Yields ◽  
Absorption Bands ◽  
Fluorescence Quantum Yields

Synthesis of A2B-type 22-oxacorroles bearing two different five-membered heterocycles at meso positions

2020 ◽  
Vol 24 (01n03) ◽  
pp. 432-439
Author(s):  
Umasekhar Booruga ◽  
Mangalampalli Ravikanth
Keyword(s):  
2D Nmr ◽  
Quantum Yields ◽  
Electrochemical Studies ◽  
2D Nmr Spectroscopy ◽  
Nmr Studies ◽  
Absorption Bands ◽  
Aryl Group ◽  
Fluorescence Quantum Yields ◽  
Acid Catalyzed ◽  
Mild Acid

A series of 22-oxacorroles containing mixed substituents such as either two five-membered heterocycles and one six-membered aryl group or three five-membered heterocycles at three meso positions were synthesized by 3 + 2 oxidative coupling of appropriate 16-oxatripyrrane and meso-substituted dipyrromethane under mild acid catalyzed conditions. The identities of the 22-oxacorroles were confirmed by the respective molecular ion peaks in HR-MS spectra and the structures were deduced by detailed 1D and 2D NMR spectroscopy. NMR studies clearly showed upfield or downfield shifts of core pyrrole and furan protons and inner NH protons depending on the type of substituent present at the meso positions. All 22-oxacorroles absorb in the 410–655 nm region, and the position of the absorption bands depends on the type of meso substituents. The A2B oxacorroles showed one broad and weak fluorescence band in the 600–700 nm region with low fluorescence quantum yields in the 0.05–0.12 range. Electrochemical studies revealed that the A2B-type 22-oxacorroles are easier to oxidize and also easier to reduce than triphenyl 22-oxacorroles. Thus, the electronic properties of 22-oxacorroles were significantly altered when six-membered aryl groups were replaced with five-membered heterocycles as reflected in spectral and electrochemical measurements.

Synthesis and photophysical properties of meso-aryloxy linked BODIPY monomers, dimers, and trimer

2016 ◽  
Vol 20 (01n04) ◽  
pp. 475-489 ◽  
Author(s):  
Changjiang Yu ◽  
Qinghua Wu ◽  
Zhonghua Tian ◽  
Tingting Li ◽  
Erhong Hao ◽  
...  
Keyword(s):  
Photophysical Properties ◽  
Spatial Arrangement ◽  
Nucleophilic Aromatic Substitution ◽  
Quantum Yields ◽  
Aromatic Substitution ◽  
Polar Solvents ◽  
Fluorescence Quantum Yields ◽  
Species Formation ◽  
The Relationship ◽  
Stokes Shifts

A series of meso-aryloxy linked BODIPY monomers, dimers and trimer were synthesized by nucleophilic aromatic substitution (SNAr) reaction from phenols with meso-chloro BODIPY and their photophysical properties were systematically studied by UV-vis and fluorescence spectroscopy. The relationship between their photophysical properties and the spatial arrangement of meso-aryloxy linked BODIPYs has been discussed. The monomers exhibited different extent solvent-dependent fluorescence, and fluorescence quenching in polar solvents were found relative to the HOMO energies of the donor (meso-phenols), indicating possible PET effect from meso-phenols to the BODIPY fluorophore. Ortho-dimer showed unusual broad red-shifted emission bands centered at 550 nm with a larger Stokes shifts at the range of 2900–3400 cm[Formula: see text], and low fluorescence quantum yields, which was in sharp contrast to those of other dimers and trimer, indicating of possible excimeric species formation due to slipped cofacial arrangement ofortho-dimer.

Fluoreszenz von Distyrylbenzolen und Distyrylstilbenen / Fluorescence of Distyrylbenzenes and Distyrylstilbenes

1982 ◽  
Vol 37 (11) ◽  
pp. 1472-1480 ◽  
Author(s):  
R. Erckel ◽  
H. Frühbeis
Keyword(s):  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Emission Spectra ◽  
Quantum Yields ◽  
Fluorescence Quantum Yields ◽  
Stokes Shifts

Absorption, corrected emission spectra, fluorescence quantum yields, and preparation are reported for distyrylbenzene, distyrylstilbene and substituted derivatives. The Stokes shifts are measured in three solvents and correlated with quantum chemical calculations.

scholarly journals One-pot three-component synthesis and photophysical characteristics of novel triene merocyanines

2014 ◽  
Vol 10 ◽  
pp. 599-612 ◽  
Author(s):  
Christian Muschelknautz ◽  
Robin Visse ◽  
Jan Nordmann ◽  
Thomas J J Müller
Keyword(s):  
Charge Transfer ◽  
Solid State ◽  
Sonogashira Coupling ◽  
Absorption Bands ◽  
One Pot ◽  
Red Emission ◽  
Long Wavelength ◽  
Dft Computations ◽  
Td Dft ◽  
Intense Absorption

Novel triene merocyanines, i.e. 1-styryleth-2-enylidene and 4-(1,3,3-trimethylindolin-2-ylidene)but-2-en-1-ylideneindolones are obtained in good to excellent yields in a consecutive three-component insertion Sonogashira coupling–addition sequence. The selectivity of either series is remarkable and has its origin in the stepwise character of the terminal addition step as shown by extensive computations on the DFT level. All merocyanines display intense absorption bands in solution and the film spectra indicate J-aggregation. While 1-styryleth-2-enylideneindolones show an intense deep red emission in films, 4-(1,3,3-trimethylindolin-2-ylidene)but-2-en-1-ylideneindolones are essentially nonemissive in films or in the solid state. TD-DFT computations rationalize the charge-transfer nature of the characteristic broad long-wavelength absorptions bands.

scholarly journals A Convenient Synthesis of Diketopyrrolopyrrole Dyes

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4758
Author(s):  
Vitor A. S. Almodôvar ◽  
Augusto C. Tomé
Keyword(s):  
High Performance ◽  
Coupling Reaction ◽  
Quantum Yields ◽  
Reaction Conditions ◽  
Fluorescence Quantum Yields ◽  
Cross Coupling Reaction ◽  
Convenient Synthesis ◽  
Organic Optoelectronic ◽  
High Fluorescence ◽  
Stokes Shifts

Diketopyrrolo[3,4-c]pyrroles (DPP) are high-performance organic optoelectronic materials. They have applications in solar cells, fluorescent probes, bioimaging, photodynamic/photothermal therapy, and in many other areas. This article reports a convenient two-step synthesis of various DPP dyes from Pigment Red 254, an inexpensive commercial pigment. The synthesis includes a Suzuki–Miyaura cross-coupling reaction of a bis(4-chlorophenyl)DPP derivative with aryl and hetaryl boronic acids under mild reaction conditions. The new dyes show large Stokes shifts and high fluorescence quantum yields, important features for their potential use in technical and biological applications.

Synthesis and Photophysical Properties of 1,4-Dihydro-2H,5H-chromeno[4,3-d][1,3]oxazin-5-ones, and Derivatives Containing Tethered 1,2,3-Triazoles, from 4-Aminocoumarins

Synthesis ◽  
2019 ◽  
Vol 51 (15) ◽  
pp. 2965-2976
Author(s):  
Marina C. Dilelio ◽  
Nathan P. Brites ◽  
Larissa A. Vieira ◽  
Bernardo A. Iglesias ◽  
Teodoro S. Kaufman ◽  
...  
Keyword(s):  
Nitrogen Atom ◽  
Click Chemistry ◽  
Photophysical Properties ◽  
Quantum Yields ◽  
One Pot ◽  
Alkyl Aryl ◽  
Triazole Derivatives ◽  
High Quantum ◽  
Stokes Shifts

A facile protocol for the unprecedented one-pot H2SO4-mediated hydroxymethylation/cyclative N,O-acetalization of 4-aminocoumarins to 1,4-dihydro-2H,5H-chromeno[4,3-d][1,3]oxazin-5-ones, in moderate to good yields, was developed and optimized. The scope and limitations of the transformation, which takes place in water or water/THF mixtures, were also studied. The nitrogen atom of the resulting tricycles was used to tether alkyl, aryl and 1,2,3-triazolylmethyl moieties, employing a two-step click chemistry approach for the latter. The photophysical properties of the heterocycles, as well as of their 1,2,3-triazole derivatives, were also examined. The N-aryl derivatives exhibited high quantum yields of fluorescence (up to Φf = 0.69) and very large Stokes shifts (up to 201 nm).

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