Unexpected discovery of estrone in the rotational spectrum of estradiol: a systematic investigation of a CP-FTMW spectrum

We report the reinvestigation of the high-resolution rotational spectrum of estradiol. After removing the known spectral lines corresponding to three conformers of estradiol identified in the gas phase before, a large number of spectral lines remained unassigned in the spectrum. The observation of r...

Full description

Saved in:
Bibliographic Details
Published in:Physical chemistry chemical physics : PCCP 2022-03, Vol.24 (9), p.5539-5545
Main Authors: Pinacho, Pablo, Caliebe, Swantje V. M, Quesada-Moreno, María Mar, Zinn, Sabrina, Schnell, Melanie
Format: Article
Language:English
Subjects:
Atomic properties
Broadband
Estradiol
Estrone
High resolution
Line spectra
Quantum chemistry
Rotational spectra
Sex hormones
Spectroscopy
Spectrum Analysis
Vapor phases
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We report the reinvestigation of the high-resolution rotational spectrum of estradiol. After removing the known spectral lines corresponding to three conformers of estradiol identified in the gas phase before, a large number of spectral lines remained unassigned in the spectrum. The observation of remaining lines is a common feature in spectra obtained by broadband rotational spectroscopy. In our reinvestigation, the detection of certain patterns resulted in two new sets of experimental rotational constants. Here we describe a systematic analysis, which together with quantum-chemical computations culminated in the assignment of two estrone conformers, namely exhibiting the trans - and the cis -arrangement of the hydroxy group attached to the rigid steroid backbone. Estrone and estradiol only differ in two atomic mass units, and they show a dynamic interconversion equilibrium under certain conditions, which might also have been the case in our experiments due to the heating temperature of 195 °C. The results illustrate the potential of high-resolution rotational spectroscopy to discern between structurally related molecules and to provide their gas-phase structures without information beforehand exploiting the benefit of having remaining unassigned rotational transitions in the spectrum. New unassigned spectral lines were found in a reinvestigation of the rotational spectrum of estradiol-17β. Several possibilities were considered leading to the assignment of the transitions to the steroid molecule estrone, a precursor of estradiol.
ISSN:1463-9076
1463-9084
DOI:10.1039/d1cp04903h