The nature of .pi.-.pi. interactions

1990 ◽  
Vol 112 (14) ◽  
pp. 5525-5534 ◽  
Author(s):  
Christopher A. Hunter ◽  
Jeremy K. M. Sanders
Keyword(s):  

2018 ◽  
Author(s):  
David Ascough ◽  
Fernanda Duarte ◽  
Robert Paton

The base-catalyzed rearrangement of arylindenols is a rare example of a suprafacial [1,3]-hydrogen atom transfer. The mechanism has been proposed to proceed via sequential [1,5]-sigmatropic shifts, which occur in a selective sense and avoid an achiral intermediate. A computational analysis using quantum chemistry casts serious doubt on these suggestions: these pathways have enormous activation barriers and in constrast to what is observed experimentally, they overwhelmingly favor a racemic product. Instead we propose that a suprafacial [1,3]-prototopic shift occurs in a two-step deprotonation/reprotonation sequence. This mechanism is favored by 15 kcal mol<sup>-1</sup> over that previously proposed. Most importantly, this is also consistent with stereospecificity since reprotonation occurs rapidly on the same p-face. We have used explicitly-solvated molecular dynamics studies to study the persistence and condensed-phase dynamics of the intermediate ion-pair formed in this reaction. Chirality transfer is the result of a particularly resilient contact ion-pair, held together by electrostatic attraction and a critical NH···p interaction which ensures that this species has an appreciable lifetime even in polar solvents such as DMSO and MeOH.



1995 ◽  
Vol 117 (8) ◽  
pp. 2377-2378 ◽  
Author(s):  
Kazuo Miyamura ◽  
Akiko Mihara ◽  
Takashi Fujii ◽  
Yohici Gohshi ◽  
Youichi Ishii


2019 ◽  
Author(s):  
Rocco Peter Fornari ◽  
Piotr de Silva

Directly linked polyanthraquinones have relatively large electronic couplings between charge-localized states despite near-orthogonality of the monomer units. By using density functional theory (DFT) and ab initio molecular dynamics (AIMD) simulations, we investigate this unusual coupling mechanism and show that this is due to strong lone pair-pi interactions, which are maximized around orthogonal conformations. We find that such materials are largely resilient to dynamic disorder and are promising for organic electronics applications.





2019 ◽  
Vol 43 (48) ◽  
pp. 19318-19330 ◽  
Author(s):  
Syed Ishtiaq Khan ◽  
Sajjad Ahmad ◽  
Ataf Ali Altaf ◽  
Muhammad Khawar Rauf ◽  
Amin Badshah ◽  
...  

This manuscript presents the synthesis of acetylthiourea and triphenylphosphene based hetroleptic copper(i) halides and their biological activities. H-bonding and hydrophobic pi-interactions were found important for their biological activities.



1980 ◽  
Vol 19 (12) ◽  
pp. 3865-3866 ◽  
Author(s):  
John L. Hubbard ◽  
Dennis L. Lichtenberger
Keyword(s):  


1988 ◽  
Vol 110 (13) ◽  
pp. 4117-4120 ◽  
Author(s):  
Rolf. Gleiter ◽  
Wolfgang. Schaefer ◽  
Gerhard. Krennrich ◽  
Hideki. Sakurai
Keyword(s):  


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