Origins of Large Stokes Shifts in a Pyrene–Styrene-Based Push–Pull Organic Molecular Dyad in Polar Solvents and Large Electron Mobility in the Crystalline State: A Theoretical Perspective

2021 ◽  
Author(s):  
Raka Ahmed ◽  
Arun K Manna
Keyword(s):  
Electron Mobility ◽  
Crystalline State ◽  
Theoretical Perspective ◽  
Polar Solvents ◽  
Stokes Shifts

Fluorescence of Cyclic Adducts of Fullerene

1994 ◽  
Vol 359 ◽  
Author(s):  
Tsung-I Lin ◽  
Syh-Kun Lin ◽  
Lung-Lin Shiu ◽  
Kuo-Ming Chien ◽  
Tien-Yau Luh
Keyword(s):  
Spectral Properties ◽  
Fluorescence Spectra ◽  
Room Temperature ◽  
Parent Compound ◽  
Molar Absorptivity ◽  
Absorption Bands ◽  
Polar Solvents ◽  
Peak Broadening ◽  
Stokes Shifts ◽  
Cyclic Adducts

ABSTRACTFive cyclic adducts C60C4H6, C60C5H6, C60NHCO2, C60NCO2Et, and C60CHCO2Et have been synthesized and their absorption and fluorescence spectral properties investigated and compared with those of the parent. Breaking the structural symmetry of C60 apparently resulted in enhancing the quantum yield two to three-folds in some adducts and thus made fluorescence much easier to be measured at room temperature. New absorption bands and altered fluorescence spectra were observed in the adducts. The Stokes' shifts of the adducts were small, about 4-5 nrm, compared to 68 nm for the parent compound. All the adducts exhibited a single fluorescence lifetime about the same as C60 (ca. 1.3 ns). Aliphatic solvents had little influence on the absorption or fluorescence spectral profile except on the molar absorptivity whereas aromatic and polar solvents strongly interacted with the adducts causing a peak broadening effect.

Dependence of the laser two-photon ionization signal of anthracene on the electron mobility and the excess energy in non-polar solvents

1995 ◽  
Vol 299 (3) ◽  
pp. 355-360 ◽  
Author(s):  
Teiichiro Ogawa ◽  
Miki Sato ◽  
Makoto Tachibana ◽  
Kazuhiko Ideta ◽  
Takanori Inoue ◽  
...  
Keyword(s):  
Electron Mobility ◽  
Excess Energy ◽  
Polar Solvents ◽  
Two Photon ◽  
Ionization Signal ◽  
Photon Ionization

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.

scholarly journals Intriguing Heteroleptic ZnII bis(dipyrrinato) Emitters in the Far-Red Region With Large Pseudo-Stokes Shift for Bioimaging

2021 ◽  
Vol 9 ◽  
Author(s):  
Roberta Tabone ◽  
Dominik Feser ◽  
Enrico D. Lemma ◽  
Ute Schepers ◽  
Claudia Bizzarri
Keyword(s):  
Cell Imaging ◽  
Photophysical Properties ◽  
Stokes Shift ◽  
Nonradiative Transition ◽  
Excitation Spectra ◽  
Polar Solvents ◽  
Heteroleptic Complexes ◽  
Intense Emission ◽  
Characteristic Features ◽  
Stokes Shifts

Novel heteroleptic ZnII bis(dipyrrinato) complexes were prepared as intriguing emitters. With our tailor-made design, we achieved far-red emissive complexes with a photoluminescence quantum yield up to 45% in dimethylsulfoxide and 70% in toluene. This means that heteroleptic ZnII bis(dipyrrinato) complexes retain very intense emission also in polar solvents, in contrast to their homoleptic counterparts, which we prepared for comparing the photophysical properties. It is evident from the absorption and excitation spectra that heteroleptic complexes present the characteristic features of both ligands: the plain dipyrrin (Lp) and the π-extended dipyrrin (Lπ). On the contrary, the emission comes exclusively from the π-extended dipyrrin Lπ, suggesting an interligand nonradiative transition that causes a large pseudo-Stokes shift (up to 4,600 cm−1). The large pseudo-Stokes shifts and the emissive spectral region of these novel heteroleptic ZnII bis(dipyrrinato) complexes are of great interest for bioimaging applications. Thus, their high biocompatibiliy with four different cell lines make them appealing as new fluorophores for cell imaging.

scholarly journals Photophysical, photostability, and ROS generation properties of new trifluoromethylated quinoline-phenol Schiff bases

2021 ◽  
Author(s):  
Inaiá O Rocha ◽  
Yuri G Kappenberg ◽  
Wilian C Rosa ◽  
Clarissa P Frizzo ◽  
Nilo Zanatta ◽  
...  
Keyword(s):  
Schiff Bases ◽  
Fluorescence Yield ◽  
Good Stability ◽  
Ros Generation ◽  
White Led ◽  
Polar Solvents ◽  
Alkyl Aryl ◽  
Yield Values ◽  
Stokes Shifts ◽  
Led Irradiation

A new series of ten examples of (E)-2-(((2-alkyl(aryl/heteroaryl)-4-(trifluoromethyl)quinolin-6-yl)imino)methyl)phenols (Schiff bases), was easy synthesized at yields up to 91% from the reactions involving a series of 2-(R-substituted) 6-amino-4-(trifluoromethyl)quinolines and 4(5)-R1-substituted salicylaldehydes – in which alkyl/aryl/heteroaryl for 2-(R)-substituents are Me, Ph, 4-MeC6H4, 4-FC6H4, 4-NO2C6H4, and 2-furyl, and (R1)-substituents are 5-NEt2, 5-OCH3, 4-Br, and 4-NO2. Complementarily, the Schiff bases showed low to good quantum fluorescence yield values both in CHCl3 (Φf = 0.12-0.80), DMSO (Φf = 0.20-0.75) and MeOH (Φf = 0.13-0.85). Higher values of Stokes shifts (SS) ​​were observed in more polar solvents (DMSO; 65-150 nm and MeOH; 65-130 nm) than in CHCl3 (59-85 nm). Also, compounds 3 confirmed to present good stability under white-LED irradiation conditions and moderate ROS generation properties were observed.

Synthesis structural and spectroscopic properties of quinoxaline-bridged bisBODIPYs

2018 ◽  
Vol 22 (09n10) ◽  
pp. 899-907
Author(s):  
Changjiang Yu ◽  
Tingting Li ◽  
Qinghua Wu ◽  
Wenbo Hu ◽  
Erhong Hao ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Intramolecular Charge Transfer ◽  
Spectroscopic Properties ◽  
Knoevenagel Reaction ◽  
X Ray Diffraction ◽  
Absorption Bands ◽  
Polar Solvents ◽  
Broad Absorption ◽  
X Ray ◽  
Stokes Shifts

Two novel quinoxaline-bridged bisBODIPYs have been synthesized by the condensation of 2,3-bis(5-formylpyrrol-2-yl)quinoxaline with 3-ethyl-2,4-dimethylpyrrole followed by a modification using a Knoevenagel reaction. They were well characterized by X-ray diffraction, NMR, HRMS UV-vis and fluorescence spectroscopy. These two quinoxaline-bridged bisBODIPYs have unusual broad absorption bands, which are different from those of typical BODIPYs They exhibit broad red-shifted emission bands centered at around 610 nm and 730 nm respectively with larger Stokes shifts at the range of 1421–2136 cm[Formula: see text] Both bisBODIPYs show different extent solvent-dependent fluorescence and exhibit fluorescence quenching in polar solvents due to the existence of possible intramolecular charge transfer.

scholarly journals Photophysical, photostability, and ROS generation properties of new trifluoromethylated quinoline-phenol Schiff bases

2021 ◽  
Vol 17 ◽  
pp. 2799-2811
Author(s):  
Inaiá O Rocha ◽  
Yuri G Kappenberg ◽  
Wilian C Rosa ◽  
Clarissa P Frizzo ◽  
Nilo Zanatta ◽  
...  
Keyword(s):  
Schiff Bases ◽  
Fluorescence Yield ◽  
Good Stability ◽  
Ros Generation ◽  
White Led ◽  
Polar Solvents ◽  
Alkyl Aryl ◽  
Yield Values ◽  
Stokes Shifts ◽  
Led Irradiation

A new series of ten examples of Schiff bases, namely (E)-2-(((2-alkyl(aryl/heteroaryl)-4-(trifluoromethyl)quinolin-6-yl)imino)methyl)phenols 3, was easily synthesized with yields of up to 91% from the reactions involving a series of 2-(R-substituted) 6-amino-4-(trifluoromethyl)quinolines 1 and 4(5)-R1-substituted salicylaldehydes 2 – in which alkyl/aryl/heteroaryl for 2-R-substituents are Me, Ph, 4-MeC6H4, 4-FC6H4, 4-NO2C6H4, and 2-furyl, and R1-substituents are 5-NEt2, 5-OCH3, 4-Br, and 4-NO2. Complementarily, the Schiff bases showed low to good quantum fluorescence yield values in CHCl3 (Φf = 0.12–0.80), DMSO (Φf = 0.20–0.75) and MeOH (Φf = 0.13–0.85). Higher values of Stokes shifts (SS) were observed in more polar solvents (DMSO; 65–150 nm and MeOH; 65–130 nm) than in CHCl3 (59–85 nm). Compounds 3 presented good stability under white-LED irradiation conditions and moderate ROS generation properties were observed.

The role of nursing in the rehabilitation of acute stroke patients: Toward a unified theoretical perspective

Pflege ◽  
1999 ◽  
Vol 12 (1) ◽  
pp. 21-27
Author(s):  
Marit Kirkevold
Keyword(s):  
Acute Stroke ◽  
Theoretical Perspective ◽  
Stroke Patients ◽  
Role Of Nursing ◽  
Rolle Der Pflegenden

Eine Übersicht der bestehenden Literatur weist auf Unsicherheiten bezüglich der spezifischen Rolle der Pflegenden in der Rehabilitation von Hirnschlagpatientinnen und -patienten hin. Es existieren zwei unterschiedliche Begrifflichkeiten für die Rolle der Pflegenden, keine davon bezieht sich auf spezifische Rehabilitationsziele oder Patientenergebnisse. Ein anfänglicher theoretischer Beitrag der Rolle der Pflege in der Genesung vom Hirnschlag wird als Struktur unterbreitet, um die therapeutischen Aspekte der Pflege im Koordinieren, Erhalten und Üben zu vereinen. Bestehende Literatur untermauert diesen Beitrag. Weitere Forschung ist jedoch notwendig, um den spezifischen Inhalt und Fokus der Pflege in der Genesung bei Hirnschlag zu entwickeln.

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