1. Rich Collection of n-Propylamine and Isopropylamine Conformers: Rotational Fingerprints and State-of-the-Art Quantum Chemical Investigation
- Author
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Lorenzo Spada, Qian Gou, Luca Dore, Yang Zheng, Meng Li, Tao Lu, Alessio Melli, Gang Feng, Mattia Melosso, Cristina Puzzarini, Vincenzo Barone, Junhua Chen, Melosso M., Melli A., Spada L., Zheng Y., Chen J., Li M., Lu T., Feng G., Gou Q., Dore L., Barone V., and Puzzarini C.
- Subjects
010304 chemical physics ,010402 general chemistry ,01 natural sciences ,Molecular physics ,Energy, Molecular structure, Energy levels, Spectroscopy ,Article ,Spectral line ,0104 chemical sciences ,chemistry.chemical_compound ,symbols.namesake ,Fourier transform ,chemistry ,0103 physical sciences ,symbols ,Density functional theory ,Rotational spectroscopy ,Isopropylamine ,Physical and Theoretical Chemistry ,Perturbation theory ,Conformational isomerism ,Basis set - Abstract
The conformational isomerism of isopropylamine and n-propylamine has been investigated by means of an integrated strategy combining high-level quantum-chemical calculations and high-resolution rotational spectroscopy. The equilibrium structures (and thus equilibrium rotational constants) as well as relative energies of all conformers have been computed using the so-called "cheap" composite scheme, which combines the coupled-cluster methodology with second-order Møller-Plesset perturbation theory for extrapolation to the complete basis set. Methods rooted in the density functional theory have been instead employed for computing spectroscopic parameters and for accounting for vibrational effects. Guided by quantum-chemical predictions, the rotational spectra of isopropylamine and n-propylamine have been investigated between 2 and 400 GHz with Fourier transform microwave and frequency-modulation millimeter/submillimeter spectrometers. Spectral assignments confirmed the presence of several conformers with comparable stability and pointed out possible Coriolis resonance effects between some of them.
- Published
- 2020