Substituent-Induced Switch of the Role of Charge-Transfer Complexes in the Diels–Alder Reactions of o-Chloranil and Styrenes

2012 ◽  
Vol 77 (14) ◽  
pp. 5971-5981 ◽  
Author(s):  
Sergiy V. Rosokha ◽  
Vasiliy Korotchenko ◽  
Charlotte L. Stern ◽  
Vladimir Zaitsev ◽  
Jeremy T. Ritzert
Keyword(s):  
Charge Transfer ◽  
Diels Alder ◽  
Charge Transfer Complexes

Self-Assembly of Alkali Lignin in Tetrahydrofuran

2012 ◽  
Vol 550-553 ◽  
pp. 57-61
Author(s):  
Hao Li ◽  
Yong Hong Deng ◽  
Kai Huang
Keyword(s):  
Charge Transfer ◽  
Electrostatic Interaction ◽  
Self Assembly ◽  
The Self ◽  
Charge Transfer Complexes ◽  
Layer By Layer ◽  
Alkali Lignin ◽  
Higher Temperature ◽  
Effects Of Temperature

Alkali lignin (AL) was used as a polyanion to form layer-by-layer self-assembled film with PDAC as a polycation. The effects of temperature and concentration on the adsorption characteristics of AL were investigated. Iodine was added into AL solutions to study the role of π-π interaction in self-assembly of AL and PDAC. Results show that the self-assembly of AL/PDAC is mainly driven by π-π interaction and electrostatic interaction. A higher temperature or a larger concentration can enhance the aggregation of lignin. I2 can form lignin–iodine charge–transfer complexes with AL to reduce the degree of aggregation of AL, so the adsorbed amount of AL decreases significantly with increasing iodine contents.

scholarly journals On the Role of Hydrogen Bond Strength and Charge Transfer of a Diels-Alder Reaction On-Water: Semiempirical and Free Energy Calculations.

2021 ◽  
Author(s):  
Andrés Henao Aristizàbal ◽  
Yomna Gohar ◽  
René Whilhelm ◽  
Thomas D. Kühne
Keyword(s):  
Hydrogen Bond ◽  
Free Energy ◽  
Charge Transfer ◽  
Hydrogen Bonds ◽  
Density Functional ◽  
Alder Reaction ◽  
Free Energy Calculations ◽  
Diels Alder ◽  
Diels Alder Reaction

Accelerated chemistry at the interface with water has received increasing attention. The mechanisms behind the enhanced reactivity On-Water are not yet clear. In this work we use a Langevin scheme in the spirit of second generation Car-Parrinello to accelerate the second-order density functional Tight-Binding (DFTB2) method in order to investigate the free energy of two Diels-Alder reaction On-Water: the cycloaddition between cyclopentadiene and ethyl cinnamate or thionocinnamate. The only difference between the reactants is the substitution of a carbonyl oxygen for a thiocarbonyl sulfur, making possible the distinction between them as strong and weak hydrogen-bond acceptors. We find a different mechanism for the reaction during the transition states and uncover the role of hydrogen bonds along with the reaction path. Our results suggest that acceleration of Diels-Alder reactions do not arise from an increased number of hydrogen bonds at the transition state and charge transfer plays a significant role. However, the presence of water and hydrogen-bonds is determinant for the catalysis of these reactions.

Charge-Transfer Complexes and Reactivity in Diels-Alder Cycloadditions

1987 ◽  
Vol 120 (8) ◽  
pp. 1315-1322 ◽  
Author(s):  
Reiner Sustmann ◽  
Mechthild Dern ◽  
Ronald Kasten ◽  
Willi Sicking
Keyword(s):  
Charge Transfer ◽  
Diels Alder ◽  
Charge Transfer Complexes

ChemInform Abstract: POSSIBLE ROLE OF CHARGE-TRANSFER COMPLEXES IN CATIONIC POLAR CYCLOADDITION

1978 ◽  
Vol 9 (29) ◽  
Author(s):  
C. K. BRADSHER ◽  
G. L. B. CARLSON ◽  
N. A. PORTER ◽  
I. J. WESTERMAN ◽  
T. G. WALLIS
Keyword(s):  
Charge Transfer ◽  
Charge Transfer Complexes
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