Acid–base properties in the triplet state of aromatic ketones studied by nanosecond laser flash photolysis

1984 ◽  
Vol 62 (10) ◽  
pp. 2041-2046 ◽  
Author(s):  
Haruo Shizuka ◽  
Ehichi Kimura
Keyword(s):  
Triplet State ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Laser Flash ◽  
Nanosecond Laser ◽  
Acid Base ◽  
Aromatic Ketones ◽  
Acid Base Equilibrium ◽  
Nanosecond Laser Flash Photolysis ◽  
Base Properties

Acid–base properties in the triplet state of aromatic ketones in H2O–CH3CN (4:1) mixtures have been studied by means of nanosecond laser flash photolysis. The acidity constants pKa(T) in the triplet state were determined by the Tn ← T1 absorbance titration curve, the Ware plot, and the Rayner–Wyatt plot. Good agreement among them shows that the acid–base equilibrium in the T1 state of aromatic ketones is established during the triplet lifetime. A linear relation between pKa(T) and the Taft σ* values was obtained for phenyl alkyl ketones.

scholarly journals Structure and Properties of the Triplet State of Styrene Derivatives Studied by Laser-Flash-Photolysis

1984 ◽  
Vol 4 (1-6) ◽  
pp. 151-170 ◽  
Author(s):  
R. Bonneau ◽  
B. Herran
Keyword(s):  
Triplet State ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Laser Flash ◽  
Nanosecond Laser ◽  
Structure And Properties ◽  
Flexible Molecules ◽  
Nanosecond Laser Flash Photolysis ◽  
Styrene Derivatives ◽  
Molecular Framework

The triplet state of a series of compounds, each containing the styrene moiety, has been studied by nanosecond laser flash photolysis. The lifetimes, the TT absorption spectra and the rate constants for deactivation by several quenchers have been determined. It is shown from these results that, in the triplet state of styrene derivatives in their lowest energy conformation, the double bond is twisted by 90° for flexible molecules (perpendicular triplet) or by an angle as large as allowed by the molecular framework of rigid molecules (twisted triplet). There is no equilibrium between planar and perpendicular (or twisted) triplets, in contrast with the case of stilbene. The influence of substituants on the lifetime of the perpendicular triplet and the mechanism of quenching of this species by oxygen have been investigated.

scholarly journals Onium salts improve the kinetics of photopolymerization of acrylate activated with visible light

RSC Advances ◽  
2020 ◽  
Vol 10 (42) ◽  
pp. 24817-24829 ◽  
Author(s):  
Janina Kabatc ◽  
Katarzyna Iwińska ◽  
Alicja Balcerak ◽  
Dominika Kwiatkowska ◽  
Agnieszka Skotnicka ◽  
...  
Keyword(s):  
Steady State ◽  
Visible Light ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Laser Flash ◽  
Nanosecond Laser ◽  
Chemical Mechanisms ◽  
Onium Salts ◽  
Nanosecond Laser Flash Photolysis ◽  
Kinetics Of

The chemical mechanisms were investigated by steady state photolysis and nanosecond laser flash photolysis experiments. A mechanism for initiating polymerization using both onium salts is proposed here.

Photocatalytic Electron Transfer in Hybrid Titania Nanosheets Studied by Nanosecond Laser Flash Photolysis

2005 ◽  
Vol 34 (11) ◽  
pp. 1522-1523 ◽  
Author(s):  
Takashi Tachikawa ◽  
Tatsuto Yui ◽  
Mamoru Fujitsuka ◽  
Katsuhiko Takagi ◽  
Tetsuro Majima
Keyword(s):  
Electron Transfer ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Laser Flash ◽  
Nanosecond Laser ◽  
Nanosecond Laser Flash Photolysis
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