Adducts of NH3with the Conformers of Glycidol: A Rotational Spectroscopy Study

Characterizing the lone pair⋯π–hole interaction in complexes of ammonia with perfluorinated arenes

Stronger and more flexible lone pair⋯π–hole interaction of ammonia with respect to water in complexes with perfluorinated arenes.

Structural and dynamical features of the 2,2,2-trifluoroethanol⋯ammonia complex

The preferred conformation of trifluoroethanol⋯ammonia is established experimentally and the effects of large vibrational motions on its properties evaluated.

Average orientation of water in CH2F2⋯H2O from the (17)O quadrupole effects in the rotational spectrum of CH2F2⋯H2(17)O

The rotational spectrum of the CH2F2⋯H2(17)O adduct has been measured in the 6.5-18.5 GHz range using a pulsed jet Fourier-transform microwave spectrometer. The experimental values of the (17)O quadrupole coupling constants have been determined to be χaa=-3.853(6), χbb=-3.259(1) and χcc=7.112(9) MHz, respectively. These data correspond to an average value of the angle between the water plane and the FCF plane of about 23°.

N lone-pair⋯π interaction: a rotational study of chlorotrifluoroethylene⋯ammonia

NH₃ forms an adduct with C₂F₃Cl through a (N)lone pair⋯π interaction.

Rotational spectra of bicyclic decanes: the trans conformation of (-)-lupinine

The conformational and structural properties of the bicyclic quinolizidine alkaloid (-)-lupinine have been investigated in a supersonic jet expansion using microwave spectroscopy. The rotational spectrum is consistent with a single dominant trans conformation within a double-chair skeleton, which is stabilized by more than 10.4 kJ mol(-1) with respect to other conformations. In the isolated conditions of the jet, the hydroxy methyl side chain of the molecule locks in to form an intramolecular O-H···N hydrogen bond to the electron lone pair at the nitrogen atom. Accurate rotational constants, centrifugal distortion corrections, and (14)N nuclear quadrupole coupling parameters are reported and compared to ab initio (MP2) and DFT (M06-2X) calculations. The stability of lupinine is further compared computationally with epilupinine and decaline in order to gauge the influence of intramolecular hydrogen bonding, absent in these molecules.

Rotational spectroscopy meets theory

Rotational spectroscopy is known to be a technique that is widely used to infer information on molecular structure and dynamics. In the last few decades, its role in the field of atmospheric and astrophysical investigations has rapidly grown. However, several are the challenging aspects in rotational spectroscopy, since the detection and analysis of spectra as well as interpretation of obtained results are not at all straightforward. Quantum chemistry has reached such an accuracy that can be used to disentangle these challenging situations by guiding the experimental investigation, assisting in the determination of the spectroscopic parameters, and extracting information of chemical interest. This perspective provides an overview of the theoretical background and computational requirements needed for the accurate evaluation of the spectroscopic parameters of relevance to rotational spectroscopy. The role of theory in guiding and supporting experiment is detailed through a few examples, and the interplay of experiment and theory is discussed in terms of the information of physical and chemical interest that can be derived.