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Updated: Jul 14, 2025

Synthesis of Esters Via a Greener Steglich Esterification in Acetonitrile
Published on: October 30, 2018
Conformational equilibria and interaction preference in the complex of isoprene-maleic anhydride
Tianyue Gao1, Juncheng Lei1, Siyu Zou1
1Department of Chemistry, School of Chemistry and Chemical Engineering, Chongqing University, Daxuecheng South Rd. 55, 401331 Chongqing, China. xuefang_xu@cqu.edu.cn.
Abstract:
The rotational spectrum of the isoprene-maleic anhydride complex has been investigated by pulsed jet Fourier transform microwave spectroscopy and interpreted with complementary quantum chemical calculations. Theoretical predictions have yielded four plausible isomers, all residing within an energy window of 12 kJ mol-1. However, two distinct isomers characterized by a π-π stacked configuration have been experimentally observed in pulsed jets, which have differed in the orientation of isoprene over maleic anhydride. The relative population ratio of the two detected isomers has been estimated to be NI/NII ≈ 3/1 from rigorous measurements of the relative intensity on a set of μc-type transitions. Remarkably, this study underscores the pivotal role played by the interaction between the CC bonding orbital (π) of isoprene and the CC antibonding orbital (π*) of maleic anhydride in stabilizing the target complex.
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