Photochemical Reactions of Diketones. II.^1a,b The 1,2-Addition of Substituted Toluenes to 9,10-Phenanthrenequinone

Influence of solvent polarity on the photoreactivity of 2–4-ring aromatic o-quinones

“…The pseudo-first-order rate constants, k obs , determined experimentally from triplet decays in the presence of any of the above mentioned H-donors are related to the corresponding quenching rate constant k Q according to eqn. (1), where k o is the triplet decay rate constant…”

“…Quenching rate constants were determined according to eqn. (1), and resulting values are summarized in Table 2. Comparison of these k Q values indicates that rate constants for the reduction of 4 triplets decrease as the polarity of the medium also decreases, observations which are consistent with charge transfer processes.…”

A combined laser flash photolysis, density functional theory and atoms in molecules study of the photochemical hydrogen abstraction by pyrene-4,5-dione

“…The photochemistry of ␣-diketones (and the closely related ortho-quinones) has been a subject of interest for a long time and this field of investigation has continued to be very active [6]. Several ortho-quinones have been found to be photoreactive in the presence of hydrogen and electron donors [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24].…”

“…The irradiation of ortho-quinones in the presence of olefins leads to the formation of dihydrodioxins (DHDs) [6][7][8]12,[28][29][30]. These adducts have been used as a photoactivated masking group for DNA cleavage [31].…”

An Annular Center-Line Light Source Photochemical Reactor. Design Equations and Experimental Results

“…Dev., Vol. 15 study was the reaction of 9,10-phenanthrenequinone (PQ) with 1,4-dioxane (solvent) to give the 1:1 adduct This reaction has been studied previously with a monochromatic light source by Rubin (1963Rubin ( , 1969 and Rubin and Zwitkowitz (1964) and is known to be a clean reaction with a quantum efficiency of unity in the absence of oxygen. Absorbance curves for PQ and adduct are shown in Figure 1.…”