Skip to Main content Skip to Navigation
Journal articles

The Scent of Maibowle – π Electron Localization in Coumarin from Its Microwave‐Determined Structure

Abstract : The microwave spectra of the natural substance coumarin, a planar aromatic molecule with the specific scent of maibowle, a popular fruit punch served in spring and early summer, were recorded using a molecular jet Fourier transform microwave spectrometer working in the frequency range from 4.0 to 26.5 GHz. The rotational constants and centrifugal distortion constants were determined with high precision, reproducing the spectra to experimental accuracy. The spectra of all singly-substituted 13C and 18O isotopologues were observed in their natural abundances to determine the experimental heavy atom substitution rs and semiexperimental equilibrium re SE structures. The experimental bond lengths and bond angles were compared to those obtained from quantum chemical calculations and those of related molecules reported in the literature with benzene as the prototype. The alternation of the CC bond lengths to the value of 1.39 Å found for benzene reflects the localization of π electrons in coumarin, where the benzene ring and the lactone-like chain −CH=CH−(C=O)−O− are fused. The large, negative inertial defect of coumarin is consistent with out-of-plane vibrations of the fused rings.
Document type :
Journal articles
Complete list of metadata

https://hal.u-pec.fr//hal-03182668
Contributor : Ha Vinh Lam Nguyen <>
Submitted on : Friday, March 26, 2021 - 2:53:54 PM
Last modification on : Thursday, April 15, 2021 - 3:08:17 PM

File

CMR_HAL.pdf
Files produced by the author(s)

Identifiers

Collections

Citation

Ha Vinh Lam Nguyen, Jens-Uwe Grabow. The Scent of Maibowle – π Electron Localization in Coumarin from Its Microwave‐Determined Structure. ChemPhysChem, Wiley-VCH Verlag, 2020, 21 (12), pp.1243-1248. ⟨10.1002/cphc.202000234⟩. ⟨hal-03182668⟩

Share

Metrics

Record views

40

Files downloads

65