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.

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.

scholarly journals New chromophores based on combination of ethylenedioxythiophene and carbazole fragments: synthesis and optoelectronic properties

2016 ◽  
Vol 4 (1) ◽  
Author(s):  
A.N. Bakiev ◽  
O.A. Mayorova ◽  
A.A. Gorbunov ◽  
I.V. Lunegov ◽  
E.V. Shklyaeva ◽  
...  
Keyword(s):  
Band Gap ◽  
Visible Spectrum ◽  
Band Gap Energy ◽  
Gap Energy ◽  
Good Solubility ◽  
Film Forming ◽  
Photovoltaic Applications ◽  
Key Steps ◽  
Homo Lumo ◽  
Stokes Shifts

AbstractTwo new D-π-A chromophores composed of an electron-donating carbazole unit linked through π- bridges, bearing 3,4-ethylenedioxythiophene (EDOT) moiety, with an electron withdrawing dicyanovinyl group (DCV) were successfully synthesized involving Suzuki or Heck cross-coupling and Knöevenagel reactions as the key steps. The obtained compounds absorb light over a broad spectral range, including the visible spectrum. The HOMO/LUMO energies and band gap energy values (Eg) were calculated on the basis of the experimental optical and electrochemical data: HOMO, LUMO, Eg (eV), −5.51, −3.14, 2.37 (4), −5.34, −3.14, 2.20 (7). The presence of the HC=CH unit in compound 7 resulted in the increase of the HOMO energy level, the decrease of a band gap value and red shifts of the absorption and emission bands in comparison with those of 4. Large Stokes shifts and broadband luminescence inherent to both chromophores suggest their use as materials for luminescent solar collectors (LSCs). The obtained compounds demonstrated good solubility and suitable thin-film forming properties. For this reason, they may be suitable for solution-processable photovoltaic applications.

Ground- and Excited-State Absorption Spectra of 9-Acetoxy-10(4´-Acetoxy)phenylanthracenes

1986 ◽  
Vol 41 (10) ◽  
pp. 1200-1209
Author(s):  
Janina R. Heldt
Keyword(s):  
Mirror Symmetry ◽  
Energy Levels ◽  
Bathochromic Shift ◽  
Heavy Atom ◽  
Excited State Absorption ◽  
Spectroscopic Properties ◽  
Quantum Yields ◽  
Fluorescence Quantum Yields ◽  
Ring Molecules ◽  
Meso Position

The ground-(S0) and excited -(S1 and T1) state spectra of seven derivatives o f 9-acetoxy- 10(4´-acetoxy)phenylanthracene were determined in the region 50000 - 15000 cm -1 (200 - 660 nm). Comparison of these spectra to the unsubstituted molecule (anthracene) indicates the presence o f bathochromic shift and the steric effect. The substituents cause changes of positions of the energy levels (bigger shifts are noticed for low lying states) and also changes of the absorption intensities of some transitions. The steric hindrances between the phenyl-substituents and the anthracene skeleton are more pronounced if the - OAc(- Me) group or a heavy atom is introduced at position 2´o f the phenyl ring. Molecules possessing such substituents at the meso-position exhibit spectroscopic properties characteristic for a plane molecule in the S0 and S1 states; they show a better preservation of the mirror symmetry between the absorption and fluorescence spectra, lower Stokes shifts and the destabilization energies and bigger fluorescence quantum yields.

New D–π-A push–pull chromophores as low band gap molecular semiconductors for organic small molecule solar cell applications

2018 ◽  
Vol 5 (5) ◽  
pp. 777-787 ◽  
Author(s):  
Abbasriyaludeen Abdul Raheem ◽  
Santhosh Kamaraj ◽  
Veeman Sannasi ◽  
Chandrasekar Praveen
Keyword(s):  
Solar Cell ◽  
Band Gap ◽  
Energy Levels ◽  
Organic Photovoltaic ◽  
Lumo Energy ◽  
Low Band Gap ◽  
Photovoltaic Applications ◽  
Pull Systems ◽  
Molecular Semiconductors ◽  
Homo Lumo

Low band gap molecular semiconductors based on push–pull systems with appropriate HOMO–LUMO energy levels for organic photovoltaic applications were accomplished.

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.

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.

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