Experimental and Theoretical Study of O-Substituent Effect on the Fluorescence of 8-Hydroxyquinoline

Zayed, Mohie E. M.; El‐Shishtawy, Reda M.; Elroby, Shaaban A.; Obaid, Abdullah Y.; Alamshany, Zahra M.

doi:10.3390/ijms16023804

Cited by 4 publications

(2 citation statements)

References 29 publications

(30 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this study, the latest revision of the Gaussian 09 program package [ 28 ] was used for all TD-DFT calculations [ 41 , 42 ]. To optimize the ground state geometry of xylene isomers, the PBEPBE functional [ 29 , 30 ] together with the 6-31 + G (d, p) basis set [ 31 ] was employed, which has been used previously for different organic compounds and verified to give certain geometrical structures and normal mode frequencies [ 43 ].…”

Section: Resultsmentioning

confidence: 99%

Fluorescence and photophysical properties of xylene isomers in water: with experimental and theoretical approaches

Khan¹,

Wu²,

Liu³

et al. 2018

R. Soc. open sci.

View full text Add to dashboard Cite

A thorough analysis of the photophysical properties involved in electronic transitions in excitation–emission spectra of xylene isomers has been carried out using the time-dependent density functional theory (PBEPBE/6-31 + G(d,p)) method. For the first time a structural and spectroscopic investigation to distinguish isomers of xylene, a widespread priority pollutant, was conducted experimentally and theoretically. The fluorescence properties of xylene isomers (sole and mixture (binary and ternary)) in water were studied. The fluorescence peak intensities of xylenes were linearly correlated to concentration, in the order of p-xylene > o-xylene > m-xylene at an excitation/emission wavelength (ex/em) of 260 nm/285 nm for o-, m-xylene and ex/em 265 nm/290 nm for p-xylene at the same concentration. The theoretical excitation/emission wavelengths were at ex/em 247 nm/267 nm, 248 nm/269 nm and 251 nm/307 nm for o-, m- and p-xylene, respectively. The vertical excitation and emission state energies of p-xylene (ex/em 4.94 eV/4.03 eV) were lower and the internal conversion energy difference (0.90 eV) was higher than those of m-xylene (ex/em 5.00 eV/4.60 eV) (0.4 eV) and o-xylene (ex/em 5.02 eV/4.64 eV) (0.377 eV). The order of theoretical emission and oscillator strength (0.0187 > 0.0175 > 0.0339) for p-xylene > o-xylene > m-xylene was observed to be in agreement with the experimental fluorescence intensities. These findings provide a novel fast method to distinguish isomers based on their photophysical properties.

show abstract

Section: Resultsmentioning

confidence: 99%

Fluorescence and photophysical properties of xylene isomers in water: with experimental and theoretical approaches

Khan¹,

Wu²,

Liu³

et al. 2018

R. Soc. open sci.

View full text Add to dashboard Cite

show abstract

“…Studied compounds were varied with two different donors, e.g., methyl and anisole. The optimized structures (see Figure S1) were used to calculate the spatial distribution of HOMO and LUMO levels (see Figure ), transition energies (using TD-DFT), and natural transition orbitals − (NTOs, see Figure ). The distribution of HOMO and LUMO energy levels is shown in Figure .…”

Section: Resultsmentioning

confidence: 99%

Exploring an Emissive Charge Transfer Process in Zero-Twist Donor–Acceptor Molecular Design as a Dual-State Emitter

et al. 2016

View full text Add to dashboard Cite

The present work reports a new concept on how to diminish dark twist intramolecular charge transfer (TICT) states with the zero-twist D−A systems in order to design frameworks with dual solution and solid-state emission property. The study began with theoretical calculations to understand the structural needs followed by the chemical synthesis of conceptually new two molecular designs, 1 and 2, with zero-twist angle between electron donor and acceptor units linked through a covalent bond and finally their applications in OLED devices. Oxazole was used as an acceptor in combination with the phenothiazene core as the donor, and the effect of enhanced electron donation was studied using methyl and anisole donor groups. DFT studies indicated a partial segregation of HOMO−LUMO levels in molecular designs, and the photophysics of these planar charge transfer molecules have been investigated. Natural transition orbital (NTO) calculations were carried out to understand excited-state transition character in these D−A molecules. Molecular level studies through single-crystal analysis revealed the importance of steric factor in controlling other molecular parameters, particularly short-range molecular forces. The synthesized compounds were eventually utilized in green-emitting OLED devices as a pristine emitting layer. Compound 2 showed better device efficiency than 1 in unoptimized devices largely due to the presence of the anisole group which prevented stacking of molecules. Solution-state emission and electroluminescence data of fabricated devices using 1 and 2 pointed out that molecular modification helped to enhance emission efficiency of 2 without shifting the emission wavelength.

show abstract

Exploring the antioxidant “cut-off effect” of gallic acid alkyl esters in dried oysters (Crassostrea gigas) during storage

Zhao,

Luo,

et al. 2023

Food Bioscience

View full text Add to dashboard Cite

Experimental and Theoretical Study of O-Substituent Effect on the Fluorescence of 8-Hydroxyquinoline

Cited by 4 publications

References 29 publications

Fluorescence and photophysical properties of xylene isomers in water: with experimental and theoretical approaches

Fluorescence and photophysical properties of xylene isomers in water: with experimental and theoretical approaches

Exploring an Emissive Charge Transfer Process in Zero-Twist Donor–Acceptor Molecular Design as a Dual-State Emitter

Exploring the antioxidant “cut-off effect” of gallic acid alkyl esters in dried oysters (Crassostrea gigas) during storage

Contact Info

Product

Resources

About