2007/08/31 by Frank Filsinger, Kirstin Wohlfart, Melanie Schnell +2
Chemistry · Earth and Planetary Sciences · Physics and Astronomy · #Ab initio quantum chemistry methods #Atmospheric Ozone and Climate #Conformational isomerism #Coupling constant #Dipole #Hamiltonian (control theory) #Hyperfine structure #Molecular Spectroscopy and Structure #Quadrupole #Rotational spectroscopy #Spectroscopy and Laser Applications #physics.atom-ph #physics.chem-ph
paper · pdf · doi:10.1039/b711888k
published as Phys. Chem. Chem. Phys. 10(5), 666-673 (2008) · 9 pages, 4 tables, 3 figures (RevTeX)
openalex publication_date 2008/01/01 · arxiv created 2008/01/23 · openalex created_date 2016/06/24 · arxiv updated 2016/07/06 · openalex updated_date 2026/08/05
The rotational constants and the nitrogen nuclear quadrupole coupling constants of cis-3-aminophenol and trans-3-aminophenol are determined using Fourier-transform microwave spectroscopy. We examine several J = 2 <-- 1 and 1 <-- 0 hyperfine-resolved rotational transitions for both conformers. The transitions are fit to a rigid rotor Hamiltonian including nuclear quadrupole coupling to account for the 14N nuclear spin. For cis-3-aminophenol we obtain rotational constants of A = 3734.930 MHz, B = 1823.2095 MHz, and C = 1226.493 MHz, for trans-3-aminophenol of A = 3730.1676 MHz, B = 1828.25774 MHz, and C = 1228.1948 MHz. The dipole moments are precisely determined using Stark effect measurements for several hyperfine transitions to micro(a) = 1.7718 D, micro(b) = 1.517 D for cis-3-aminophenol and micro(a) = 0.5563 D, micro(h) = 0.5375 D for trans-3-aminophenol. Whereas the rotational constants and quadrupole coupling constants do not allow to determinate the absolute configuration of the two conformers, this assignment is straightforward based on the dipole moments. High-level ab initio calculations (B3LYP/6-31G* to MP2/aug-cc-pVTZ) are performed providing error estimates of rotational constants and dipole moments obtained for large molecules by these theoretical methods.