DOUBLE-MINIMUM POTENTIAL FOR INTRAMOLECULARLY HYDROGEN-BONDED PROTONS IN ORTHO-SUBSTITUTED ANILINES

1964 ◽  
Vol 42 (2) ◽  
pp. 201-211 ◽  
Author(s):  
P. J. Krueger

The concentration and temperature-independent splitting of the first overtone NH2 symmetric stretching band in 31 ortho-substituted anilines in which intramolecular hydrogen bonding is possible is interpreted in terms of a double-minimum potential for the hydrogen bonded proton. The intensity ratio of the doublet and the extent of the splitting is related to the basicity of the ortho-substituent, modified by the rigid geometrical restrictions of the intramolecular system. The absence of band splitting in the corresponding fundamental mode suggests that the secondary minimum lies in the vicinity of the v = 2 vibrational level. The antisymmetric mode appears to be less sensitive to perturbations.Deuteration studies, the spectra of some o-substituted N-methyl anilines, and the first over-tone bands of N-methyl aniline in very basic solvents support these views.

1970 ◽  
Vol 23 (8) ◽  
pp. 1667 ◽  
Author(s):  
JM Appleton ◽  
BD Andrews ◽  
ID Rae ◽  
BE Reichert

The proton magnetic resonance spectra of deuterochloroform solutions of a number of ortho-substituted anilines and their S-acyl derivatives have been measured. Variations in the acylation shifts of the ring protons are explained in terms of intramolecular hydrogen bonding between the amide proton and the ortho-substituent. Calculations of the contribution made to the acylation shifts by the anisotropy of the amide group were found to be too sensitive to the molecular geometry to be of any real value. Acylation shifts for a series of 4'-substituted 2'-nitroacetanilides correlate well with the σp values of the 4'-substituents.


1976 ◽  
Vol 54 (4) ◽  
pp. 642-646 ◽  
Author(s):  
R. S. Brown

The photoelectron spectra of cis- and trans-2-aminocyclopentanol and cis- and trans-2-(N,N,-dimethylamino)cyclopentanol have been recorded and interpreted. The cis isomers exhibit N lone pair ionizations at higher ionization energy, and O lone pair ionizations at lower ionization energy than their trans isomers.The results are most consistent with the existence and observation of intramolecular hydrogen-bonding in the cis isomers. Infrared data on these systems also show that the cis isomers exist in the intramolecularly hydrogen-bonded state.


1996 ◽  
Vol 49 (11) ◽  
pp. 1251
Author(s):  
CF Carvalho ◽  
DP Arnold ◽  
RC Bott ◽  
G Smith

The crystal structure of the asymmetric 1,3-diol 1,1-diphenylbutane-1,3-diol has been determined and refined to a residual R of 0.039 for 795 observed reflections. Crystals are orthorhombic, space group P212121, with four molecules in a cell of dimensions a 9.625(4), b 16.002(3), c 8.834(3) Ǻ. The compound is unique among the known crystallographically characterized open-chain 1,3-diols in having only intramolecular hydrogen bonding involving the hydroxy groups [O-- -O 2.602(5) Ǻ].


1969 ◽  
Vol 47 (9) ◽  
pp. 1587-1592 ◽  
Author(s):  
A. F. Casy ◽  
M. M. A. Hassan

Hydroxyl stretching frequency data upon 1-dimethylamino-3,3-diphenylhexan-4-ol and related amino-alcohols are reported which give evidence of unusually strong intramolecular hydrogen bonding between the hydroxy and t-amino functions of these compounds. In corresponding salts, concentration independent vOH bands, typical of hydrogen bonded species, also occur and a bonded system comprising anion, OH, and N+H functions is proposed together with probable methadol base and salt conformations.


2018 ◽  
Vol 9 (26) ◽  
pp. 5828-5836 ◽  
Author(s):  
Asia Marie S. Riel ◽  
Daniel A. Decato ◽  
Jiyu Sun ◽  
Casey J. Massena ◽  
Morly J. Jessop ◽  
...  

Intramolecular hydrogen bonding directly to halogen bond donors preorganizes molecular structure and strengthens halogen bonding.


2020 ◽  
Vol 315 ◽  
pp. 113730
Author(s):  
Michael H. Abraham ◽  
Raymond J. Abraham ◽  
Amin Aghamohammadi ◽  
Kamyar Afarinkia ◽  
Xiangli Liu

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