The molecular structure of chlorobenzene, determined by the combined analysis of electron diffraction, rotation constant and liquid crystal nuclear magnetic resonance data

Substitution effects in phenyl and N-pyrrole derivatives along the periodic table

“…Taken from references a [27], b [28], c [29], d [30], e [31], f [32], g [33], h [34], i [35], j [36], k [37] Struct Chem (2007) In the case of pyrrole derivatives, the more electropositive atoms, defined as the ones located in the first three columns of the periodic table, present a tendency while the rest have the opposite one for each bond. Thus, the N1-C2 bond tends to increase from the first to the third column of the periodic table, and then it decreases along the periodic table.…”

Accurate structures from combined gas electron diffraction and liquid crystal NMR data; the importance of anisotropy of indirect couplings for 1,4-difluorobenzene

“…It is not possible to draw any firm conclusions as to which set of corrections is better, but it is clear that any set must be treated with appropriate caution. A survey of the results of this and some previous studies of aromatic compounds 4,6,25 indicates that the uncertainties are roughly proportional to the magnitudes of the correction terms, and that 10% of the magnitude, with a lower limit of 0.1 Hz, is a reasonable and safe figure to use in assigning uncertainties. With a force field calculated ab initio at a very high level, one could take a less conservative position, but we would not at present go below 2 or 3% of the ab initio magnitude.…”

“…The latter combination has been particularly successful for aromatic rings, for which the absence of lowfrequency vibrational modes has been a significant beneficial factor. [4][5][6] A systematic study of chlorinated benzenes [6][7][8][9][10][11][12][13] was undertaken primarily to assess the validity of combining gas-phase and solution-phase data, and it has been demonstrated that the accuracy of these combined analyses matches their impressive precision. 14 Interactions between solvents and solutes do not distort the structures significantly.…”

Anisotropy of indirect couplings and accurate molecular structures of 1,2- and 1,3-difluorobenzenes by combined analysis of gas electron diffraction, rotational spectroscopy and liquid crystal NMR data

“…Gas electron-diffraction data and rotation constants are routinely combined, and we have also been able to use dipolar couplings obtained by LCNMR. The latter combination has been particularly successful for aromatic rings, for which the absence of low-frequency vibrational modes has been a significant beneficial factor [4][5][6].…”

“…A systematic study of chlorinated benzenes [6][7][8][9][10][11][12][13] was undertaken primarily to assess the validity of combining gas-phase and solution-phase data, and it has been demonstrated that the accuracy of these combined analyses matches their impressive precision [14], so it is shown that at least for these molecules interactions between solvents and solutes do not distort the structures significantly. The structures of these chlorobenzenes also showed the effects of multiple substitution.…”