Synlett 2023; 34(10): 1159-1168
DOI: 10.1055/s-0042-1751415
cluster
Dispersion Effects

Noncovalent Interactions in Crowded Benzene Systems: How Much Strain Is Too Much? Attractions Overcome Repulsions!

a   Faculty of Interdisciplinary Research, Competence Centre CALOR, University of Rostock, 18059 Rostock, Germany
b   Department of Physical Chemistry, Kazan Federal University, 420008 Kazan, Russian Federation
,
Artemiy A. Samarov
c   Saint Petersburg State University, Peterhof, 198504 Saint Petersburg, Russian Federation
,
Kseniya V. Zherikova
d   Nikolaev Institute of Inorganic Chemistry of Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russian Federation
› Author Affiliations
SPV acknowledge financial support from the Deutsche Forschungsgemeinschaft (DFG) in the frame of the priority program SPP 1807 ‘Control of London Dispersion Interactions in Molecular Chemistry’ (Grant VE 265-9/2). This paper was supported by the Kazan Federal University Strategic Academic Leadership Program (‘PRIORITY-2030’). AAS acknowledges gratefully a research scholarship from the Deutscher Akademischer Austauschdienst (DAAD) and the Committee on Science and Higher Education of the Government of St. Petersburg. Interpretation of dispersion interactions and nonadditive effects (Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences) was financially supported by the Russian Science Foundation and the Government of the Novosibirsk Region (project No. 22-23-20182). Processing of data was supported by the Ministry of Science and Higher Education of the Russian Federation (N 121031700314-5).


Abstract

In molecular design, large alkyl groups are used to introduce bulk and steric crowding of the catalytic center to improve catalytic efficiency and selectivity. The bulky groups are highly polarizable, increasing their ability to participate in stabilizing noncovalent interactions. The rationalization of noncovalent interaction trends is of both fundamental and practical interest as it provides new design concepts for catalysis and synthesis. Highly congested molecules always present challenges to chemists. Crowded benzene systems are an important class of compounds with well-established thermodynamic properties. The latter were used in this work to develop tools to quantify the degree of stabilization or destabilization in benzene systems crowded with bulky isopropyl and tert-butyl substituents. The basic idea was to quantify the delicate balance between repulsive and attractive interactions inherent in crowded benzene systems. The ensemble of experimental thermodynamic data and DFT-D3 calculations enabled the development of quantitative scales of the dispersion contributions and their understanding at the molecular level.



Publication History

Received: 07 November 2022

Accepted after revision: 12 January 2023

Article published online:
10 February 2023

© 2023. Thieme. All rights reserved

Georg Thieme Verlag KG
Rüdigerstraße 14, 70469 Stuttgart, Germany