ELECTRON-WITHDRAWING EFFECTS ON THE MOLECULAR STRUCTURE OF 2- AND 3-NITROBENZONITRILE REVEALED BY BROADBAND MICROWAVE SPECTROSCOPY

Nitrobenzonitrile consists of two electron-withdrawing groups, which have negative inductive and mesomeric effects on the phenyl ring resulting in interesting physical properties. The rotational spectra of 2- and 3-nitrobenzonitrile were recorded via chirped-pulse Fourier transform microwave spectroscopy in the frequency range of 2$-$8 GHz. For both molecules, the main isotopologues and all isotopologues of the respective $^{13}$C-, $^{15}$N-, $^{18}$O-monosubstituted species in their natural abundance were assigned. These assignments allowed for the structural determination of 2- and 3-nitrobenzonitrile via Kraitchman's equations as well as a mass-dependent least-squares fitting approach. Structural changes caused by steric interaction and competition for the electron density of the phenyl ring highlight how these strong electron-withdrawing substituents affect one another according to their respective positions on the phenyl ring

Theoretical study of M+ RG2: (M+= Ca, Sr, Ba and Ra; RG= He–Rn)

Ab initio calculations were employed to investigate M+ RG2 species, where M+ = Ca, Sr, Ba and Ra and RG= He–Rn. Geometries have been optimized, and cuts through the potential energy surfaces containing each global minimum have been calculated at the MP2 level of theory, employing triple-ζ quality basis sets. The interaction energies for these complexes were calculated employing the RCCSD(T) level of theory with quadruple-ζ quality basis sets. Trends in binding energies, De, equilibrium bond lengths, Re, and bond angles are discussed and rationalized by analyzing the electronic density. Mulliken, natural population, and atoms-in-molecules (AIM) population analyses are presented. It is found that some of these complexes involving the heavier Group 2 metals are bent whereas others are linear, deviating from observations for the corresponding Be and Mg metal-containing complexes, which have all previously been found to be bent. The results are discussed in terms of orbital hybridization and the different types of interaction present in these species

ELECTRON-WITHDRAWING EFFECTS ON THE MOLECULAR STRUCTURE OF 2- AND 3-NITROBENZONITRILE REVEALED BY BROADBAND MICROWAVE SPECTROSCOPY

Nitrobenzonitrile consists of two electron-withdrawing groups, which have negative inductive and mesomeric effects on the phenyl ring resulting in interesting physical properties. The rotational spectra of 2- and 3-nitrobenzonitrile were recorded via chirped-pulse Fourier transform microwave spectroscopy in the frequency range of 2$-$8 GHz. For both molecules, the main isotopologues and all isotopologues of the respective $^{13}$C-, $^{15}$N-, $^{18}$O-monosubstituted species in their natural abundance were assigned. These assignments allowed for the structural determination of 2- and 3-nitrobenzonitrile via Kraitchman's equations as well as a mass-dependent least-squares fitting approach. Structural changes caused by steric interaction and competition for the electron density of the phenyl ring highlight how these strong electron-withdrawing substituents affect one another according to their respective positions on the phenyl ring

Electron-withdrawing effects on the molecular structure of 2- and 3-nitrobenzonitrile revealed by broadband rotational spectroscopy and their comparison with 4-nitrobenzonitrile

The rotational spectra of 2- and 3-nitrobenzonitrile were recorded via chirped-pulse Fourier transform microwave spectroscopy in the frequency range of 2–8 GHz. These molecules each display large dipole moments, making them viable candidates for deceleration and trapping experiments with AC-electric fields. For both molecules, the main isotopologues and all isotopologues of the respective 13C-, 15N-, 18O-monosubstituted species in their natural abundance were assigned. These assignments allowed for the structural determination of 2- and 3-nitrobenzonitrile via Kraitchman's equations as well as a mass-dependent least-squares fitting approach. The experimentally determined structural parameters are then compared to those obtained from quantum-chemical calculations for these two molecules and 4-nitrobenzonitrile. Structural changes caused by steric interaction and competition for the electron density of the phenyl ring highlight how these strong electron-withdrawing substituents affect one another according to their respective positions on the phenyl ring