Organic photochemistry. 35. Structural effects on the nonradiative decay of alkylbenzenes. The nature of the ".alpha.-substitution effect"

1977 ◽  
Vol 99 (10) ◽  
pp. 3342-3345 ◽  
Author(s):  
W. W. Schloman ◽  
Harry Morrison
Keyword(s):  
Substitution Effect ◽  
Structural Effects ◽  
Nonradiative Decay ◽  
Organic Photochemistry

Substitution effect on the nonradiative decay and trans → cis photoisomerization route: a guideline to develop efficient cinnamate-based sunscreens

2021 ◽  
Author(s):  
Shin-nosuke Kinoshita ◽  
Yu Harabuchi ◽  
Yoshiya Inokuchi ◽  
Satoshi Maeda ◽  
Masahiro Ehara ◽  
...  
Keyword(s):  
Substitution Effect ◽  
Nonradiative Decay

Para-substituted cinnamates are promising sunscreen reagents. They undergo efficient multistep nonradiative decay via the 1nπ* (and/or 3nπ*) and 3ππ* states and finally trans → cis photoisomerization. Para-substitution stabilizes π orbitals and enhances the photoisomerization.

the effects of resonance with Jupiter in the system of short-period comets

1974 ◽  
Vol 22 ◽  
pp. 193-203
Author(s):  
L̆ubor Kresák
Keyword(s):  
Structural Effects ◽  
Order Resonance ◽  
Mean Motion ◽  
Short Period ◽  
The Mean ◽  
Compound Effect ◽  
Low Order

AbstractStructural effects of the resonance with the mean motion of Jupiter on the system of short-period comets are discussed. The distribution of mean motions, determined from sets of consecutive perihelion passages of all known periodic comets, reveals a number of gaps associated with low-order resonance; most pronounced are those corresponding to the simplest commensurabilities of 5/2, 2/1, 5/3, 3/2, 1/1 and 1/2. The formation of the gaps is explained by a compound effect of five possible types of behaviour of the comets set into an approximate resonance, ranging from quick passages through the gap to temporary librations avoiding closer approaches to Jupiter. In addition to the comets of almost asteroidal appearance, librating with small amplitudes around the lower resonance ratios (Marsden, 1970b), there is an interesting group of faint diffuse comets librating in characteristic periods of about 200 years, with large amplitudes of about±8% in μ and almost±180° in σ, around the 2/1 resonance gap. This transient type of motion appears to be nearly as frequent as a circulating motion with period of revolution of less than one half that of Jupiter. The temporary members of this group are characteristic not only by their appearance but also by rather peculiar discovery conditions.

Structural effects on print-through and set-off

2012 ◽  
Vol 27 (3) ◽  
pp. 596-603
Author(s):  
Gary Chinga- Carrasco ◽  
Kenneth Aasarød ◽  
Berit Leinsvang ◽  
Mikael Bouveng ◽  
Per-Åke Johansson
Keyword(s):  
Structural Effects

Vapour-Liquid Equilibria and Excess Thermodynamic Properties in Binary Systems of Cyclopentanone + Chloroalkanes in View of the Disquac and Unifac Group Contribution Models Extention

2008 ◽  
Vol 59 (5) ◽  
Author(s):  
Alexandru Birhala ◽  
Dana Dragoescu ◽  
Mariana Teodorescu
Keyword(s):  
Binary Systems ◽  
Excess Enthalpy ◽  
Group Contribution ◽  
Excess Properties ◽  
Structural Effects ◽  
Liquid Equilibrium ◽  
Excess Thermodynamic Properties ◽  
Different Types ◽  
Thermodynamic Excess Properties ◽  
Thermodynamic Excess

The data available in the literature and our recent data on vapour�liquid equilibrium (VLE), excess Gibbs energy, GE, and excess enthalpy, HE, for the homologous series of cyclopentanone + chloroalkane mixtures are examined in terms of the predictive group contribution models DISQUAC and UNIFAC. In our treatment, we present also how the structural effects and different types of molecular interactions are reflected by the thermodynamic excess properties of the mentioned series mixtures.

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