scholarly journals Deconstructive Cycloaromatization Strategy towards N,O-Bidentate Ligands and Their Four-Coordinate Organoboron Complexes

2022 ◽  
Author(s):  
Jinlei Zhou ◽  
Xiaotian Shi ◽  
Huitao Zheng ◽  
Guangxian Chen ◽  
Chen Zhang ◽  
...  
Keyword(s):  
Material Science ◽  
Functional Group ◽  
Scale Up ◽  
Quantum Yields ◽  
Bidentate Ligands ◽  
Bright Fluorescence ◽  
Boron Complexes ◽  
Homo Lumo ◽  
Stokes Shifts ◽  
Straightforward Approach

Abstract The innovative construction of novel N,O-bidentate ligands and N,O π-conjugated four-coordinate organoboron complexes represent a long-standing challenge for chemists. Here, we report an unprecedented and straightforward approach for the construction of N,O-bidentate ligands and their organoboron complexes via the merge of ring deconstruction with cycloaromatization of indolizines and cyclopropenones. Without any catalysts, our method is able to deliver a series of polyaryl 2-(pyridin-2-yl)phenol ligands, N,O π-conjugated organoboron (BF2 and BAr2) complexes with good functional-group compatibility which are difficult or even impossible to synthesize with previous methods. Importantly, the formed N,O-bidentate ligands were easy to scale up and derive with valuable drugs and active molecules. In addition, the photoluminescence measurements and the HOMO/LUMO gap have been investigated, the results have revealed that N,O π-conjugated tetracoordinate boron complexes display bright fluorescence, large Stokes shifts, and good quantum yields (Φlum = 0.15–0.45). The method proposed by the paper will inspire the development of various N,O-bidentate metal and boron complexes, which is expected to move the area of catalysis chemistry and material science forward.

scholarly journals Aminomaleimide fluorophores: a simple functional group with bright, solvent dependent emission

2015 ◽  
Vol 51 (47) ◽  
pp. 9733-9736 ◽  
Author(s):  
Anne B. Mabire ◽  
Mathew P. Robin ◽  
Wen-Dong Quan ◽  
Helen Willcock ◽  
Vasilios G. Stavros ◽  
...  
Keyword(s):  
Functional Group ◽  
Quantum Yields ◽  
New Class ◽  
High Quantum ◽  
Stokes Shifts

Amino-substituted maleimides form a new class of highly emissive compounds, with large Stokes shifts (>100 nm) and high quantum yields (up to ∼60%).

Novel Dual BODIPY-Carbazole Conjugates with Various Linkers

2017 ◽  
Vol 70 (7) ◽  
pp. 806 ◽  
Author(s):  
Qiao Zong ◽  
Hongbin Zhao ◽  
Weinan Zhou ◽  
Wentao Zhang ◽  
Junxu Liao ◽  
...  
Keyword(s):  
Energy Levels ◽  
Molecular Geometry ◽  
Quantum Yields ◽  
Visible Absorption ◽  
Fluorescence Quantum Yields ◽  
Photovoltaic Applications ◽  
Shoulder Peak ◽  
Membered Heterocycle ◽  
Homo Lumo ◽  
Stokes Shifts

Four dual BODIPY-carbazole conjugates (BDPa–d, BODIPY is 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene), with various π bridges, including none, phenyl, thiophene, and furan, were designed and synthesized. The results suggest that the π bridges have significant effect on the thermal, photophysical, and electrochemical properties of the conjugates. BDPc and BDPd, with a five-membered heterocycle as a π bridge possessing more coplanar molecular geometry, exhibit broader and red-shifted absorption with an obvious charge transfer shoulder peak, as well as red-shifted emission. UV-visible absorption spectroscopy and cyclic voltammetry results show that the extension of the π-conjugated system leads to a reduction in the optical gap with a decrease of the LUMO level. All conjugates display remarkable Stokes shifts (107–216 nm) and low fluorescence quantum yields. BDPc and BDPd, which essentially possess broad and intense absorption, and suitable HOMO–LUMO energy levels, are potential candidates for light-harvesting and photovoltaic applications.

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.

Visible-Light-Induced Radical Polynitration of Arylboronic Acids: Synthesis of Polynitrophenols

Synthesis ◽  
2018 ◽  
Vol 50 (15) ◽  
pp. 2891-2896 ◽  
Author(s):  
Jinna Song ◽  
Xihe Bi ◽  
Qi Zhang ◽  
Kaki Raveendra Babu ◽  
Zhouliang Huang
Keyword(s):  
Visible Light ◽  
Aromatic Compounds ◽  
Functional Group ◽  
Simple Procedure ◽  
One Pot ◽  
Arylboronic Acids ◽  
Mild Conditions ◽  
Conventional Methods ◽  
Straightforward Approach

We report a visible light-assisted one-pot method for the synthesis of polynitrophenols through radical tandem hydroxylation and nitration of arylboronic acids by utilizing copper(II) nitrate tri­hydrate as the nitro source. This method features mild conditions, a simple procedure, and good functional group tolerance. Compared to conventional methods, this work provides a straightforward approach for the polynitration of aromatic compounds.

scholarly journals Decagram Synthesis of Dimethyl 1,4-Cubanedicarboxylate Using Continuous-Flow Photochemistry

Synthesis ◽  
2020 ◽  
Author(s):  
Bruno Linclau ◽  
Diego E. Collin ◽  
Edward H. Jackman ◽  
Nicolas Jouandon ◽  
Wei Sun ◽  
...  
Keyword(s):  
Residence Time ◽  
Continuous Flow ◽  
Scale Up ◽  
Process Time ◽  
Materials Chemistry ◽  
Highly Strained ◽  
Straightforward Approach

AbstractThe highly strained cubane system is of great interest as a scaffold and rigid linker in both pharmaceutical and materials chemistry. A straightforward approach is reported for the scale-up of a [2+2] photocycloaddition step using convenient home-made flow photoreactors to access dimethyl 1,4-cubanedicarboxylate on decagram-scale in 33–40% yield over 8 steps. The process is demonstrated on 3.4 g·h–1 input with 30 minutes residence time, enabling to reduce the process time and to avoid the use of batch photoreactors. Completion of the characterisation of the photocycloadduct and its hydrates is reported.

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.

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.

Synthesis, X-ray diffraction analysis, and chemical–optical characterizations of boron complexes from bidentate ligands

Polyhedron ◽  
2012 ◽  
Vol 43 (1) ◽  
pp. 194-200 ◽  
Author(s):  
Mario Rodríguez ◽  
José Luis Maldonado ◽  
Gabriel Ramos-Ortíz ◽  
Oscar Domínguez ◽  
Ma. Eugenia Ochoa ◽  
...  
Keyword(s):  
Diffraction Analysis ◽  
Bidentate Ligands ◽  
X Ray Diffraction ◽  
X Ray ◽  
Boron Complexes

scholarly journals Copper-Catalyzed Simultaneous Activation of C–H and N–H Bonds: Three-Component One-Pot Cascade Synthesis of Multi­substituted Imidazoles

Synthesis ◽  
2017 ◽  
Vol 50 (02) ◽  
pp. 361-370 ◽  
Author(s):  
Lucio Melone ◽  
Atul Chaskar ◽  
Sachin Pardeshi ◽  
Pratima Sathe ◽  
Kamlesh Vadagaonkar
Keyword(s):  
Copper Sulfate ◽  
Functional Group ◽  
One Pot ◽  
Modular Synthesis ◽  
Simultaneous Activation ◽  
Arylacetic Acids ◽  
The One ◽  
Straightforward Approach

A copper-catalyzed expedient, practical, and straightforward approach for the one-pot three-component modular synthesis of multisubstituted imidazoles has been described by using arylacetic acids, N-arylbenzamidines, and nitroalkanes. The reaction involves simultaneous activation of C–H and N–H bonds of arylacetic acids and N-arylbenzamidines, respectively. The use of inexpensive copper sulfate as a catalyst, readily available starting materials, and Celite-free workup makes this protocol economically viable. Multisubstituted imidazoles were obtained in moderate to good yields with significant functional group tolerance and high regioselectivity.

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