scholarly journals Optical Characteristics and Applications of AIE Racemic C6-Unsubstituted Tetrahydropyrimidines

2021 ◽  
Vol 9 ◽  
Author(s):  
Qiuhua Zhu
Keyword(s):  
Optical Properties ◽  
Molecular Packing ◽  
Molecular Structures ◽  
Optical Characteristics ◽  
Quantum Yields ◽  
Central Ring ◽  
Strong Emission ◽  
Aryl Ring ◽  
Fluorescence Quantum Yields

Racemic C6-unsubstituted tetrahydropyrimidines (THPs) are the products of an efficient five-component reaction that we developed. THPs show strong AIE characteristics, that is, completely no fluorescence in different solvents but strong emission with fluorescence quantum yields (ΦF) up to 100% upon aggregation. However, the ΦF values of their pure enantiomers are lower than 46%. Unlike common AIE compounds with crowded aryl rotors on a π-bond or on an aryl ring, THPs have three completely non-crowded aryl rotors on a non-aromatic chiral central ring (tetrahydropyrimidine). In this mini review, we first discuss the AIE characteristics of THPs and the influences of molecular structures on their molecular packing modes and optical properties, and then present their applications and forecast the development of other racemic AIE compounds.

1,4,7,10-Tetraisoalkyltetracenes: Tuning of Solid-State Optical Properties and Fluorescence Quantum Yields by Peripheral Modulation (Eur. J. Org. Chem. 16/2010)

2010 ◽  
Vol 2010 (16) ◽  
pp. 2987-2987
Author(s):  
Chitoshi Kitamura ◽  
Hideki Tsukuda ◽  
Akio Yoneda ◽  
Takeshi Kawase ◽  
Takashi Kobayashi ◽  
...  
Keyword(s):  
Optical Properties ◽  
Solid State ◽  
Quantum Yields ◽  
Fluorescence Quantum Yields

scholarly journals Synthesis and properties of 5,10,15,20-tetra[4-(3,5-dioctoxybenzamidephenyl] porphyrin and its metal complexes

2012 ◽  
Vol 77 (3) ◽  
pp. 335-348 ◽  
Author(s):  
Wenhui Lian ◽  
Yuanyuan Sun ◽  
Binbin Wang ◽  
Ning Shan ◽  
Tongshun Shi
Keyword(s):  
Metal Complexes ◽  
Raman Spectra ◽  
Metal Ion ◽  
Spectroscopic Properties ◽  
Molecular Structures ◽  
Photoelectron Spectra ◽  
Quantum Yields ◽  
Xps Spectra ◽  
Fluorescence Quantum Yields ◽  
Porphyrin Ligand

A novel 5,10,15,20-tetra[4-(3,5-dioctoxybenzamide)phenyl]porphyrin and its transition metal complexes are reported in this paper. Their molecular structures were characterized by elemental analysis, IR spectra, 1HNMR spectra and UV-Vis spectra. Their spectroscopic properties were studied by Raman spectra, fluorescence spectra and X-ray photoelectron spectra (XPS). The fluorescence quantum yields have been measured at room temperature. The fluorescence intensity of porphyrin ligand was stronger than that of the complexes. In Raman spectra, there was much difference between porphyrin ligand and its metal complexes due to changes of the symmetry of porphyrin plane. In the XPS spectra, the replacement of the free-base protons by a metal ion to form the metalloporphyrin increases the symmetry of the molecule also introduces an electron with-drawing group into the center of the porphyrin ligand which increases the N1s binding energy.

scholarly journals 1,4,7,10-Tetraisoalkyltetracenes: Tuning of Solid-State Optical Properties and Fluorescence Quantum Yields by Peripheral Modulation

2010 ◽  
Vol 2010 (16) ◽  
pp. 3033-3040 ◽  
Author(s):  
Chitoshi Kitamura ◽  
Hideki Tsukuda ◽  
Akio Yoneda ◽  
Takeshi Kawase ◽  
Takashi Kobayashi ◽  
...  
Keyword(s):  
Optical Properties ◽  
Solid State ◽  
Quantum Yields ◽  
Fluorescence Quantum Yields

Synthesis of π-extended B ← N coordinated phenanthroimidazole dimers and their linear and nonlinear optical properties

2020 ◽  
Vol 49 (23) ◽  
pp. 7737-7746
Author(s):  
Mukundam Vanga ◽  
Shreenibasa Sa ◽  
Anupa Kumari ◽  
Anna Chandrasekar Murali ◽  
Prakash Nayak ◽  
...  
Keyword(s):  
Optical Properties ◽  
Nonlinear Optical ◽  
Photon Absorption ◽  
Quantum Yields ◽  
Conjugation Length ◽  
Absorption Properties ◽  
Two Photon Absorption ◽  
Fluorescence Quantum Yields ◽  
Two Photon ◽  
Linear And Nonlinear

B ← N coordinated phenanthroimidazole dimers exhibit excellent fluorescence quantum yields in solution and conjugation length dependant two-photon-absorption properties.

scholarly journals New electroactive asymmetrical chalcones and therefrom derived 2-amino- / 2-(1H-pyrrol-1-yl)pyrimidines, containing an N-[ω-(4-methoxyphenoxy)alkyl]carbazole fragment: synthesis, optical and electrochemical properties

2017 ◽  
Vol 13 ◽  
pp. 1583-1595 ◽  
Author(s):  
Daria G Selivanova ◽  
Alexei A Gorbunov ◽  
Olga A Mayorova ◽  
Alexander N Vasyanin ◽  
Igor V Lunegov ◽  
...  
Keyword(s):  
Optical Properties ◽  
Electrochemical Properties ◽  
Electrochemical Oxidation ◽  
Free Electron ◽  
Quantum Yields ◽  
Synthetic Approach ◽  
Fluorescence Quantum Yields ◽  
Starting Compound ◽  
Positive Solvatochromism

In this paper we present a synthetic approach to six new D–π–A–D conjugated chromophores containing the N-[ω-(4-methoxyphenoxy)alkyl]carbazole fragment. Such readily functionalizable heterocycle as carbazole was used as a main starting compound for their preparation. The investigation of the optical properties has shown that the positive solvatochromism is inherent to the chromophores containing an electron-withdrawing prop-2-en-1-one fragment, while the compounds containing a 2-aminopyrimidine moiety exhibit both positive and negative solvatochromism. The fluorescence quantum yields were experimentally determined for some of the synthesized chromophores; e.g., 1-(5-arylthiophen-2-yl)ethanones quantum yields were found to lie in an interval of 60–80%. Electrochemical oxidation of the synthesized chromophores has resulted in the formation of colored thin oligomeric films that became possible due to the presence of carbazole or pyrrole fragments with free electron-rich positions.

Synthesis and investigation of BODIPYs with restricted meso-8-aryl rotation

2020 ◽  
Vol 24 (05n07) ◽  
pp. 869-877
Author(s):  
Guanyu Zhang ◽  
Maodie Wang ◽  
Caroline Ndung’U ◽  
Petia Bobadova-Parvanova ◽  
Frank R. Fronczek ◽  
...  
Keyword(s):  
Dihedral Angle ◽  
Quantum Yields ◽  
Methyl Groups ◽  
Free Rotation ◽  
Aryl Group ◽  
Chlorine Atoms ◽  
Aryl Ring ◽  
X Ray ◽  
Fluorescence Quantum Yields ◽  
High Fluorescence

Three BODIPYs bearing 1,3,5,7-tetramethyl substituents and a meso-8-aryl group were synthesized and investigated, both experimentally and computationally. The presence of the 1,7-methyl groups and of ortho-substituents on the meso-8-aryl ring prevent free rotation of the meso-8-aryl group, resulting in high fluorescence quantum yields. Substitution at the 2,6-positions of these BODIPYs with chlorine atoms causes pronounced red-shifted absorptions and emissions, and in the case of 2,6-dichloro-1,3,5,7-tetramethyl-8-(2,4,6-triphenylphenyl)-BODIPY 2c increases its fluorescence quantum yields to 0.93 in dichloromethane and 0.98 in toluene. The X-ray structure of 1,3,5,7-tetramethyl-8-(2,4,6-triphenylphenyl)-BODIPY shows increased deviation from planarity and smaller dihedral angle of the meso-8-aryl group compared with the meso-8-phenyl- and meso-8-mesityl-BODIPY analogs. The presence of 2,6-chlorine atoms was found to not significantly affect the rotational barriers of the meso-8-aryl-groups.

scholarly journals Photodynamic Activity of Tribenzoporphyrazines with Bulky Periphery against Wound Bacteria

2020 ◽  
Vol 21 (17) ◽  
pp. 6145 ◽  
Author(s):  
Magdalena Stolarska ◽  
Arleta Glowacka-Sobotta ◽  
Dariusz T. Mlynarczyk ◽  
Jolanta Dlugaszewska ◽  
Tomasz Goslinski ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Optical Properties ◽  
Singlet Oxygen ◽  
Streptococcus Pyogenes ◽  
Staphylococcus Epidermidis ◽  
Quantum Yields ◽  
Resistant Bacteria ◽  
Methicillin Resistant ◽  
Fluorescence Quantum Yields ◽  
Photodynamic Activity

Magnesium(II) tribenzoporphyrazines with phenoxybutylsulfanyl substituents were evaluated as photosensitizers in terms of their optical properties against wound bacteria. In the UV-vis spectra of analyzed tribenzoporphyrazines, typical absorption ranges were found. However, the emission properties were very weak, with fluorescence quantum yields in the range of only 0.002–0.051. What is important, they revealed moderate abilities to form singlet oxygen with the quantum yields up to 0.27. Under irradiation, the macrocycles decomposed via photobleaching mechanism with the quantum yields up to 8.64 × 10−5. The photokilling potential of tribenzoporphyrazines was assessed against Streptococcus pyogenes, Staphylococcus epidermidis, as well as various strains of Staphylococcus aureus, including methicillin-sensitive and-resistant bacteria. Both evaluated photosensitizers revealed high photodynamic potential against studied bacteria (>3 logs). S.aureus growth was reduced by over 5.9 log, methicillin-resistant S. aureus by 5.1 log, S.epidermidis by over 5.7 log, and S. pyogenes by over 4.7 log.

Fluorenylethynylpyrene derivatives with strong two-photon absorption: influence of substituents on optical properties

2015 ◽  
Vol 3 (15) ◽  
pp. 3730-3744 ◽  
Author(s):  
C. Lavanya Devi ◽  
K. Yesudas ◽  
Nikolay S. Makarov ◽  
V. Jayathirtha Rao ◽  
K. Bhanuprakash ◽  
...  
Keyword(s):  
Optical Properties ◽  
Cross Sections ◽  
Photon Absorption ◽  
Quantum Yields ◽  
Absorption Cross ◽  
Two Photon Absorption ◽  
Fluorescence Quantum Yields ◽  
Two Photon ◽  
Influence Of Substituents

A series of fluorenylethynylpyrene derivatives with large two-photon absorption cross-sections (≈250–2500 GM) and good fluorescence quantum yields (Φfl = 0.55–0.98) and with high two-photon brightness were synthesized.

Regioselective Oxidative Cross-Coupling Reaction: Synthesis of Imidazo[1,2-a]pyridine Fluorophores

Synthesis ◽  
2021 ◽  
Author(s):  
Xianglong Chu ◽  
Yadi Niu ◽  
Chen Ma ◽  
Xiaodong Wang ◽  
Yunliang Lin ◽  
...  
Keyword(s):  
Photophysical Properties ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Quantum Yields ◽  
Fluorescence Quantum Yields ◽  
Cross Coupling Reaction ◽  
Color Tunable ◽  
Palladium Catalyzed ◽  
Structure Relationship ◽  
High Fluorescence

AbstractA rapid access to a series of N-heteroarene fluorophores has been developed on the basis of the palladium-catalyzed direct oxidative C–H/C–H coupling of imidazo[1,2-a]pyridines with thiophenes/furans. The photophysical properties–structure relationship was systematically investigated. The resulting N-heteroarene fluorophores present color-tunable emissions (λem: 431–507 nm in CH2Cl2) and high fluorescence quantum yields (up to 91% in CH2Cl2).

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