Photolysis of quinonediazides in cyclohexane formation of coloured adduct, heavy atom effect

1979 ◽  
Vol 44 (6) ◽  
pp. 1772-1778 ◽  
Author(s):  
Viktor Řehák ◽  
Jaroslav Poskočil ◽  
Ivo Dvořáček
Keyword(s):  
Quantum Yield ◽  
Rate Constants ◽  
Heavy Atom ◽  
Heavy Atom Effect ◽  
Atom Effect ◽  
Influence Of Solvent ◽  
The Way

Photolysis of 1,2-naphthoquinone-1-diazide and 9,10-phenathrenequinonediazide in cyclohexane gives coloured products decomposing on further irradiation. Formation of the products and their concentration depends on the way of irradiation (short, continuous) and on the presence of 1-propanol in the solution. The products are presumed to be adducts of ketene with the starting quinonediazides. Rate constants of their formation have been determined. Influence of solvent containing a heavy atom (1-bromopropane, iodoethane) on quantum yield of the photolysis and influence of oxygen have been investigated.

Halogenated tetraphenylethene with enhanced aggregation-induced emission: an anomalous anti-heavy-atom effect and self-reversible mechanochromism

2019 ◽  
Vol 55 (99) ◽  
pp. 14938-14941 ◽  
Author(s):  
Pengfei Xu ◽  
Qianqian Qiu ◽  
Xinru Ye ◽  
Mengru Wei ◽  
Wenbin Xi ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Fluorescence Quantum Yield ◽  
Heavy Atom ◽  
Aggregation Induced Emission ◽  
Heavy Atom Effect ◽  
Atom Effect

Halogenated tetraphenylethene derivatives show an anomalous anti-heavy-atom effect where introducing heavy halogens into the typical AIEgen greatly improves the fluorescence quantum yield upon aggregation, and a self-reversible mechanochromism.

Changes in the Photophysical Properties with Heavy Atoms and the Effects of Modulus for 4-Phenylphenol in Solid-Matrix Luminescence

1992 ◽  
Vol 46 (6) ◽  
pp. 988-993 ◽  
Author(s):  
Barbara B. Purdy ◽  
Robert J. Hurtubise
Keyword(s):  
Quantum Yield ◽  
Low Temperature ◽  
Young’S Modulus ◽  
Filter Paper ◽  
Room Temperature ◽  
Heavy Atom ◽  
Heavy Atom Effect ◽  
Phosphorescence Quantum Yield ◽  
Atom Effect ◽  
Fluorescence And Phosphorescence

Fluorescence and phosphorescence quantum yields and fluorescence and phosphorescence lifetimes were obtained for 4-phenylphenol adsorbed on filter paper with either NaCl, NaBr, or Nal at 296 and 93 K. From these data several photophysical parameters were calculated and compared. In general, the photophysical data showed that the heavy-atom effect was operative, with NaI showing the greatest effect. However, NaBr at 93 K showed both the heavy-atom effect and another effect which was particular to NaBr. For 4-phenylphenol with NaI, very little increase occurred for the phosphorescence quantum yield from 296 to 93 K, which indicated that almost maximum phosphorescence quantum yield was achieved at room temperature for 4-phenylphenol with NaI present. The increase in phosphorescence lifetime for 4-phenylphenol from room temperature to low temperature was shown to be related to the increase in the Young's modulus of filter paper as the temperature was lowered. Calculated phosphorescence lifetimes at room temperature and at low temperature with equations that included Young's modulus values agreed very well with experimental lifetime values.

Achieving high singlet-oxygen generation by applying the heavy-atom effect to thermally activated delayed fluorescent materials

2021 ◽  
Author(s):  
Ya-Fang Xiao ◽  
Jia-Xiong Chen ◽  
Wen-Cheng Chen ◽  
Xiuli Zheng ◽  
Chen Cao ◽  
...  
Keyword(s):  
Singlet Oxygen ◽  
Heavy Atom ◽  
Synergetic Effect ◽  
Heavy Atom Effect ◽  
Oxygen Generation ◽  
Thermally Activated ◽  
Singlet Oxygen Generation ◽  
Fluorescent Materials ◽  
Atom Effect

Applying the heavy-atom effect to TADF photosensitizers achieves ultra-high 1O2 generation (ФΔ = 0.91) by the synergetic effect of small ΔEST and considerable SOC.

Enhancement of Reverse Intersystem Crossing in Charge‐Transfer Molecule through Internal Heavy Atom Effect

2021 ◽  
pp. 2104646
Author(s):  
Hyung Suk Kim ◽  
Ja Yeon Lee ◽  
Seongjun Shin ◽  
Wonkyo Jeong ◽  
Sang Hoon Lee ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Heavy Atom ◽  
Intersystem Crossing ◽  
Heavy Atom Effect ◽  
Atom Effect

scholarly journals Etude par résonance magnétique nucléaire de composés organiques contenant des chalcogènes. II. L'éther de diphényle et ses analogues soufré, sélénié et telluré

1979 ◽  
Vol 57 (22) ◽  
pp. 2967-2970 ◽  
Author(s):  
Gabriel Llabrès ◽  
Marcel Baiwir ◽  
Léon Christiaens ◽  
Jean-Louis Piette
Keyword(s):  
Crystal Structure ◽  
Theoretical Calculations ◽  
Heavy Atom ◽  
Mesomeric Effect ◽  
Heavy Atom Effect ◽  
Inductive Effects ◽  
Structure Determinations ◽  
Résonance Magnétique ◽  
Atom Effect ◽  
Good Agreement

The 1Hmr study of the title compounds has revealed a screw conformation, with defined interconversion processes, in good agreement with crystal structure determinations and theoretical calculations. The mesomeric effect of the heteroatom is smaller than in the anisole series, due to steric inhibitions.The 13Cmr enhances, to some extent, these conclusions. In the case of Te compounds, a heavy atom effect adds to the classical mesomeric and inductive effects to account for the experimental observations.

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