Data Set Title: "Conformational data of 2chloropropionic acid"
Data Set Authors:
       Sun, Fufei           University of Bologna;	   ORCID 0009-0000-3136-1341
       Maris, Assimo        University of Bologna;     ORCID 0000-0002-0410-5833
       Evangelisti, Luca    University of Bologna;     ORCID 0000-0001-9119-1057
       Song, Wentao         University of Bologna;     ORCID 0000-0002-3267-710X
       Melandri, Sonia      University of Bologna;     ORCID 0000-0002-0410-5833
       Morán, Jose Ricardo  Universidad de Valladolid; ORCID 0009-0008-6127-1353
       Calabrese, Camilla   Universidad de Valladolid; ORCID 0000-0003-4299-2098
       Lesarri, Alberto     Universidad de Valladolid; ORCID 0000-0002-0646-6341
       Grabow, Jens-Uwe     Gottfried-Wilhelm-Leibniz Universitat; ORCID 0000-0002-2663-8091

Data Set Contact Person:
       Evangelisti, Luca      University of Bologna; ORCID 0000-0001-9119-1057; luca.evangelisti6@unibo.it 

Data Set License: this data set is distributed under Creative Commons Attribution 4.0 International. 
To view a copy of this license, visit https://creativecommons.org/licenses/by/4.0/ 

Publication Year: 2026

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Abstract

The conformational landscape of 3-chloropropionic acid was investigated using quantum-chemical calculations. Three distinct conformers were identified and subsequently optimized at the B3LYP-D3(BJ)/def2-TZVP level of theory. The rotational spectra of the different conformers were analyzed using the SPFIT/SPCAT suite, and the resulting spectroscopic parameters are reported. For each conformer, the most abundant isomer and its 37Cl isotopologue in natural abundance were observed and assigned.
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Data set contents

The dataset consists of a .zip archive, named “Conformational_data_of_2chloropropionic_acid.zip”, containing the following files and folders:

Conformational_data_of_2chloropropionic_acid.zip
|   README.txt
|
+---2ClPA_I_conformer
|       1cl35.fit
|       1cl37.fit
|       conf1Cl35.out
|       conf1Cl37.out
|
|
+---2ClPA_II_conformer
|       2cl35.fit
|       2cl37.fit
|       conf2Cl35.out
|       conf2Cl37.out
|
|
\---2ClPA_III_conformer
        3cl35.fit
        3cl37.fit
        conf3Cl35.out
		conf3Cl37.out

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Dataset documentation

The three different subfolders ("2ClPA_I_conformer", "2ClPA_II_conformer", "2ClPA_III_conformer") are named after the molecules of interest. In each of these subfolders are stored: 

(i)    The experimental fits of the conformer with chlorine-35 isotopologue
       Xcl35.fit (with X=1,2,3)
	   
(ii)   The experimental fits of the conformer with chlorine-37 isotopologue
       Xcl37.fit (with X=1,2,3)

(iii)  Gaussian output optimization files of the conformers at the B3LYP-D3(BJ)/Def2-TZVP level of calculation
       confXClY.out (with X=1,2,3 for conformer identification and Y=35 or 37 for isotopologue identification) 
 
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Methodolology

Computational results were obtained with “Gaussian 16” software, available at https://gaussian.com/
The fit of the experimental rotational transition lines was performed with the SPFIT/SPCAT software available at http://info.ifpan.edu.pl/~kisiel/asym/asym.htm#pickett

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File specifics

All files are in ASCII format and can be opened with a text editor.
The Gaussian output files (.out) can also be opened with special graphical software: 
- gaussview (proprietary software, available at https://gaussian.com/gaussview6/) 
- avogadro (open software, available at https://avogadro.cc/) 
- molden (open software, available at https://www.theochem.ru.nl/molden/, only for .out files)

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Notes

The data are provided to reproduce the results of the article entitled: "The conformational space of 3-chloropropionic acid in gas phase explored by rotational spectroscopy" (submitted). 
