Design of diethynyl porphyrin derivatives with high near infrared fluorescence quantum yields

2015 ◽  
Vol 19 (01-03) ◽  
pp. 205-218 ◽  
Author(s):  
Kimihiro Susumu ◽  
Michael J. Therien
Keyword(s):  
Radiative Decay ◽  
Near Infrared ◽  
Design Strategy ◽  
Oscillator Strengths ◽  
Quantum Yields ◽  
High Quantum Yield ◽  
Radiative Decay Rate ◽  
Near Infrared Fluorescence ◽  
Fluorescence Quantum Yields ◽  
Porphyrin Derivatives

A design strategy for (porphinato)zinc-based fluorophores that possess large near infrared fluorescence quantum yields is described. These fluorophores are based on a (5,15-diethynylporphinato)zinc(II) framework and feature symmetric donor or acceptor units appended at the meso-ethynyl positions via benzo[c][1,2,5]thiadiazole moieties. These (5,15-bis(benzo[c][1′,2′,5′]thiadiazol-4′-ylethynyl)-10,20-bis[2′,6′-bis(3″,3″-dimethyl-1″-butyloxy)phenyl]porphinato)zinc(II) (4), (5,15-bis[4′-(N,N-dihexylamino) benzo[c][1′,2′,5′]thiadiazol-7′-ylethynyl]-10,20-bis[2′,6′-bis(3″,3″-dimethyl-1″-butyloxy)phenyl]porphinato)zinc(II) (5), (5,15-bis([7′-(4″-n-dodecyloxyphenylethynyl)benzo[c][1′,2′,5′]thiadiazol-4′-yl]ethynyl)-10,20-bis[2′,6′-bis(3″,3″-dimethyl-1″-butyloxy)phenyl]porphinato)zinc(II) (6), (5,15-bis([7′-([7″-(4″ ′-n-dodecyloxyphenyl)benzo[c][1″,2″,5″]thiadiazol-4″-yl]ethynyl)benzo[c][1′,2′,5′]thiadiazol-4′-yl]ethynyl)-10,20-bis[2′,6′-bis(3″,3″-dimethyl-1″-butyloxy)phenyl]porphinato)zinc(II) (7), 5,15-bis ([7′-(4″-N,N-dihexylaminophenylethynyl)benzo[c][1′,2′,5′]thiadiazol-4′-yl]ethynyl)-10,20-bis[2′,6′-bis(3″,3″-dimethyl-1″-butyloxy)phenyl]porphinato)zinc(II) (8), and (5,15-bis([7′-(4″-N,N-dihexylaminophenylethenyl)benzo[c][1′,2′,5′]thiadiazol-4′-yl]ethynyl)-10,20-bis[2′,6′-bis(3″,3″-dimethyl-1″-butyloxy)phenyl]porphinato)zinc(II) (9) chromophores possess red-shifted absorption and emission bands that range between 650 and 750 nm that bear distinct similarities to those of the chlorophylls and structurally related molecules. Interestingly, the measured radiative decay rate constants for these emitters track with the integrated oscillator strengths of their respective x-polarized Q-band absorptions, and thus define an unusual family of high quantum yield near infrared fluorophores in which emission intensity is governed by a simple Strickler–Berg dependence.

Fluorescence behaviour of some 4-substituted halobenzenes

1985 ◽  
Vol 50 (8) ◽  
pp. 1753-1763 ◽  
Author(s):  
Bohumír Koutek ◽  
Lubomír Musil ◽  
Jiří Velek ◽  
Milan Souček
Keyword(s):  
Decay Rate ◽  
Radiative Decay ◽  
Mean Value ◽  
Quantum Yields ◽  
Intersystem Crossing ◽  
Radiative Decay Rate ◽  
Fluorescence Quantum Yields ◽  
Band Position ◽  
Fluorescence Characteristics ◽  
Acetonitrile Solutions

The fluorescence characteristics of 4-substituted chloro and fluorobenzenes I and II were studied in isooctane and acetonitrile solutions. It was found that all compounds exhibit a weak (substituent and solvent dependent) fluorescence in the range 305-370 nm with quantum yields 1.2 . 10-2-2.3 . 10-1. The relation between the substituent nature and fluorescence band position may be quantified by log νf~ = ρσp + log νf~0, the magnitude of the shift paralleling the donor strength of the substituent. Fluorescence quantum yields are increased approximately by a factor 2 on going from isooctane to acetonitrile and solvent-induced shifts are proportional to the static dipole moment change Δμ which occurs upon excitation. Radiative decay rate varies only slightly around a mean value of 5 . 107 s-1 and shows no substantial difference between chloro (I) and fluoro (II) derivatives. The non-radiative decay rate (of the order ~ 109 s-1) was found to be about 5 times higher in the case of chloro compounds due to the more efficient S1 - Tn intersystem crossing.

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.

scholarly journals Inverted energy gap law for the nonradiative decay in fluorescent floppy molecules: larger fluorescence quantum yields for smaller energy gaps

2019 ◽  
Vol 6 (12) ◽  
pp. 1948-1954 ◽  
Author(s):  
Junqing Shi ◽  
Maria A. Izquierdo ◽  
Sangyoon Oh ◽  
Soo Young Park ◽  
Begoña Milián-Medina ◽  
...  
Keyword(s):  
Radiative Decay ◽  
Energy Gap ◽  
Quantum Yields ◽  
Nonradiative Decay ◽  
Fluorescence Quantum Yields ◽  
Energy Gaps ◽  
Energy Gap Law ◽  
Solution Increase ◽  
Floppy Molecules ◽  
Franck Condon

The non-radiative decay of substituted dicyano-distyrylbenzenes in solution increase with the Franck–Condon energy, being opposite to the conventional energy gap law.

The influence of phenylethynyl linkers on the photo-physical properties of metal-free porphyrins

2000 ◽  
Vol 04 (07) ◽  
pp. 669-683 ◽  
Author(s):  
GARY A. BAKER ◽  
FRANK V. BRIGHT ◽  
MICHAEL R. DETTY ◽  
SIDDHARTH PANDEY ◽  
COREY E. STILTS ◽  
...  
Keyword(s):  
Excited State ◽  
Radiative Decay ◽  
Phenyl Group ◽  
Quantum Yields ◽  
Fluorescence Lifetimes ◽  
Strongly Coupled ◽  
Metal Free ◽  
Fluorescence Quantum Yields ◽  
Porphyrin Core ◽  
Absorbance Spectra

Series of 5,10,15,20-tetraarylporphyrins 1 and 5,10,15,20-tetrakis[4-(arylethynyl)phenyl]porphyrins 2 were prepared via condensation of pyrrole with the appropriate benzaldehyde or 4-(arylethynyl)benzaldehyde derivative (3). Condensation of meso-phenyldipyrromethane with mixtures of benzaldehyde and 4-(trimethylsilyl-ethynyl)benzaldehyde gave a separable mixture of mono- (6), bis- (both cis-7 and trans-8) and tris[4-(trimethylsilylethynyl)phenyl]porphyrin (9). Following removal of the trimethylsilyl groups of 6–9, the 4-ethynylphenyl groups of 11–14 were coupled to 1-iodo-3,5-di(trifluoromethyl)benzene with Pd ( OAc )2 to give 15–18 bearing one, two (both cis- and trans-) and three 4-[bis-3,5-(trifluoromethyl)phenylethynyl]phenyl groups respectively. Coupling of 11 and 1-iodo-4-nitrobenzene with Pd ( OAc )2 gave porphyrin 19 with one 4-(4-nitrophenylethynyl)phenyl group. Porphyrin 24 with a p-quinone linked to the porphyrin core via a phenylethynyl group was prepared via similar chemistry. The absorbance spectra, emission maxima, excited-state fluorescence lifetimes, quantum yields of fluorescence, rates of fluorescence and rates of non-radiative decay were measured for each of the porphyrins. Absorbance spectra and emission maxima were nearly identical for all the porphyrins of this study, which suggests that the aryl groups and 4-(arylethynyl)phenyl groups are not strongly coupled to the porphyrin core in these metal-free compounds. Fluorescence quantum yields and rates of radiative decay were larger for porphyrins bearing 4-(arylethynyl)phenyl groups, while excited-state fluorescence lifetimes were somewhat shorter. These effects were additive for each additional 4-(arylethynyl)phenyl group.

scholarly journals Free Rotor Styrylcyanine Chromogens

1986 ◽  
Vol 6 (6) ◽  
pp. 381-389 ◽  
Author(s):  
M. M. Habashy ◽  
M. S. Antonious ◽  
M. Abdel-Kader ◽  
M. S. A. Abdel-Mottaleb
Keyword(s):  
Radiative Decay ◽  
Decay Channel ◽  
Stokes Shift ◽  
Solvent Polarity ◽  
Quantum Yields ◽  
Excitation Wavelength ◽  
Charge Densities ◽  
Fluorescence Quantum Yields ◽  
Organized Assemblies ◽  
Sensitive Function

Fluorescence spectra (maximum wavelength λF) and fluorescence quantum yields (φF) were measured for four structurally related styrylcyanine chromogens of the pyridinium and quinolinium type (1–4) in different solvents at ambient temperature and 77 K. The response of λF and φF values to changes in solvent polarity, solvent hydrogen bonding donor strength, viscosity and temperature was a sensitive function of chromogen structure. The sensitivities of the λF and φF values correlate with the degree of charge transfer character of the S1,CT state; Stokes shift of fluorescence was progressively decreased while φF value was enhanced as the CT character of S1,CT state increases. Moreover, a large edge-excitation red shift was observed in ethanol glass at 77 K. The dominant photophysical features for these dyes are discussed in terms of strong emission from an intramolecular CT state characterized by different solvation sites indicated by the observation of the excitation-wavelength dependent phenomenon in ethanol at 77 K and an important non-radiative decay channel involving rotation of the different parts of molecules leading to a more relaxed weakly fluorescent S1,CT created in fluid media. The viscosity dependence of fluorescence properties (a marked increase in φF was observed with increasing viscosity) suggests that these dyes can be useful reporters of microviscosity for different sites in various organized assemblies. Moreover, it was suggested that increasing H-bonding donor strength of the solvent activates a rotatory non-radiative decay channel probably by localizing charge densities and decreasing CT nature of the S1,CT state.

Near-infrared Ag2Se quantum dots with distinct absorption features and high fluorescence quantum yields

RSC Advances ◽  
2016 ◽  
Vol 6 (44) ◽  
pp. 38183-38186 ◽  
Author(s):  
Li-Juan Shi ◽  
Chun-Nan Zhu ◽  
He He ◽  
Dong-Liang Zhu ◽  
Zhi-Ling Zhang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Near Infrared ◽  
Quantum Yields ◽  
Extinction Coefficients ◽  
Fluorescence Quantum Yields ◽  
High Fluorescence ◽  
Absorption Features ◽  
Molar Extinction Coefficients

Near-infrared Ag2Se QDs with distinct absorption features ranging between 830–954 nm and fluorescence quantum yields up to 23.4% were controllably synthesized, and the molar extinction coefficients of the Ag2Se QDs were determined.

ENHANCED NEAR-INFRARED FLUORESCENCE FROM DYE-DOPED CORE-SHELL Ag/SiO2 NANOWIRES

2009 ◽  
Vol 23 (05) ◽  
pp. 709-714 ◽  
Author(s):  
MIN LI ◽  
ZHANG-KAI ZHOU ◽  
YUE-YING ZHAI ◽  
HAO SONG ◽  
ZONG-SUO ZHANG ◽  
...  
Keyword(s):  
Decay Rate ◽  
Radiative Decay ◽  
Near Infrared ◽  
Cyanine Dye ◽  
Metal Particles ◽  
Core Shell ◽  
Photoluminescence Intensity ◽  
Laser Dye ◽  
Radiative Decay Rate ◽  
Nir Laser

We have studied the increase of the radiative decay rate of heptamethine cyanine NIR laser dye within core-shell Ag/SiO 2 nanowires. The photoluminescence intensity and lifetime of the heptamethine cyanine dye are affected by the Ag nanowires. Both the photoluminescence intensity and the decay rate of the heptamethine cyanine dye are greatly enhanced by the Ag nanostructures and are caused by the interactions between the excited-state fluorophore and the local electric field near the metal particles.

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