Photooxidation of 3,5-diaryl-1-phenyl-2-pyrazolines: Experimental and computational studies

Soltani, Marzieh; Memarian, Hamid Reza; Sabzyan, Hassan

doi:10.1016/j.jphotochem.2019.112285

Cited by 8 publications

(2 citation statements)

References 46 publications

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“…Longer irradiation times lead to a net decrease in the amount of pyrazoline as the pyrazoline absorbance peak starts to decrease again, possibly due to photooxidation of the adduct. 24 Formation of pyrazoline adducts in P3 proceeded similarly to P1, reaching a maximum pyrazoline concentration for P3-G after five hours irradiation at 66% conversion before a decrease of the pyrazoline absorption sets in. This corresponds to 5.4 grafts per chain.…”

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Simultaneously controlling conformational and operational stability of single-chain polymeric nanoparticles in complex media

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confidence: 88%

Simultaneously controlling conformational and operational stability of single-chain polymeric nanoparticles in complex media

et al. 2023

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“…In continuation to our previous studies concerning the elucidation of the steric and electronic effects of substitution of various heterocyclic rings on the thermal [10,11] and photochemical oxidation [12,13], the spectral characteristic [14,15], and cyclic voltammetric and computational studies [16,17], we were interested to investigate these effects on the fluorescence ability of various substituted 2-pyrazolines. In addition to the photo-physical works, the results of the computational study may explain the effect of the electronic and steric effects of the ring substitutions on the energies of the molecular orbitals describing the fluorescence ability of these compounds.…”

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Electronic and steric substituent effects on the fluorescence emission of 2‐pyrazoline derivatives

Memarian,

Rejali,

Soltani

2023

Luminescence

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A series of substituted 2‐pyrazolines were synthesized, and the steric and electronic effects of substituents on the C3‐ and C5‐positions of the heterocyclic ring on their fluorescent ability were investigated. Two different conjugative intramolecular charge transfer (ICT) and intramolecular charge transfer through space (spiro‐conjugation) affect the fluorescence intensity of these compounds. The extent of the ICT process and spiro‐conjugation depends on the electronic nature of the additional substitution and its position on the attached aryl rings. In addition, the effects of the concentration and the solvent polarity on the fluorescence emission were studied. Density functional theory (DFT) calculations were carried out to gain insight into the geometric, electronic, and spectroscopic properties of the pyrazoline derivatives. The results of both experimental and computational studies explain the effects of the geometrical orientation of the C3‐ and C5‐aryl rings toward the heterocyclic ring and also the electronic nature of their additional substitutions on the fluorescence intensity.

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Photoinduced 1,3‐Dipolar Cycloadditions of Cyclic Enones and 2,5‐Disubstituted Tetrazoles: An Unprecedented Pathway to Polysubstituted Pyrazolines and Pyrazoles

Labassi,

Fournier‐Le Ray,

Gauffre

et al. 2023

Eur J Org Chem

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We report herein the syntheses of original pyrazolines and pyrazoles through 1,3‐dipolar cycloaddition of cyclic enones with 2,5‐disubstituted nitrile imines achieved via photochemical activation of 2,5‐diaryl substituted tetrazoles. Monitoring of the reactions, similar to nitrile imine‐mediated tetrazole‐ene cycloadditions (NITEC), could be performed by means of UV‐vis absorption and emission measurements. The presence or absence of substituents in the alpha position of the ketone function makes it possible to direct these reactions towards the selective formation of pyrazoles or pyrazolines. The choice of the cyclic enones and 2,5‐disubstituted tetrazoles proved crucial for the fluorescence properties of the polycyclic derivatives obtained.

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Photooxidation of 3,5-diaryl-1-phenyl-2-pyrazolines: Experimental and computational studies

Cited by 8 publications

References 46 publications

Simultaneously controlling conformational and operational stability of single-chain polymeric nanoparticles in complex media

Simultaneously controlling conformational and operational stability of single-chain polymeric nanoparticles in complex media

Electronic and steric substituent effects on the fluorescence emission of 2‐pyrazoline derivatives

Photoinduced 1,3‐Dipolar Cycloadditions of Cyclic Enones and 2,5‐Disubstituted Tetrazoles: An Unprecedented Pathway to Polysubstituted Pyrazolines and Pyrazoles

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