β-Amino ketoximes: a study of basicity, hydrogen bonding and isomerism

1977 ◽  
Vol 30 (7) ◽  
pp. 1467 ◽  
Author(s):  
HK Powell ◽  
JM Russell

The protonation reactions of the diamine dioxime 4,4,9,9-tetramethyl- 5,8-diazadodecane-2,11-dione dioxime and its O-methyl and bis-O-methyl ethers have been studied at 25�, I 0.10 M NaCl. The (substituted) oxime groups cause a marked reduction in the basicity of the secondary amino groups. log K (potentiometric) and ΔH (calorimetric) data are interpreted in terms of inductive effects of the oxime group and possible intramolecular hydrogen bonding, N+-H...N(OR)=, pKa for methoxy-amine, NH2OMe, has been determined (4.62�0.01, I 0.10 M NaCl, 25�). ������ P.m.r. spectra are assigned for β-amino ketoximes having α- methyl and α-methylene groups cis and trans to =N-OR groups. Infrared spectra are reported.

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.


1976 ◽  
Vol 54 (12) ◽  
pp. 1929-1937 ◽  
Author(s):  
R. S. Brown

The photoelectron spectra of several well defined molecules exhibiting intramolecular hydrogen bonding has been determined and the analysis of the spectra is in accord with recent molecular orbital calculations of related systems. The experimentally determined enthalpies of the hydrogen bonds in cis-2-aminocyclopentanol and cis- and trans-2-aminocyclohexanol do not correlate in any simple fashion with the shifts in the ionization energies of the nO and nN orbitals compared to a model which precludes hydrogen bonding. The spectral differences attributed to hydrogen bonding in the cis and trans 2-substituted cyclanols cannot be attributed to differences in the through-bond interaction of the n orbitals on either atom since the cis and trans isomers of 1,2-dimethoxycyclopentane and 1,2-dimethoxycyclohexane show virtually identical pe spectra. A discussion of the applicability of Koopmans' theorem and the effect of the hydrogen bond in both the ion and ground states is presented.


1960 ◽  
Vol 13 (4) ◽  
pp. 456
Author(s):  
A Bryson ◽  
RL Werner

The presence of intramolecular hydrogen bonding in 2-nitro-1-naphthylamine, 1-nitro-2-naphthylamine, 3-nitro-2-naphthylamine, and 8-nitro-1-naphthylamine is inferred from a study of the NH frequencies of the 14 isomeric mononitronaphthylamines in the solvents carbon tetrachloride and pyridine. The NH stretching frequencies are decreased in pyridine as a result of hydrogen bonding between the amino group and the solvent. The extent of this decrease is quite uniform for all nitronaphthylamines except those in which the nitro and amino groups are adjacent, and in these cases the decrease is about half that observed from the remaining compounds. This is interpreted as indicating the presence of intramolecular hydrogen bonding in the latter group, the extent of which reduces the degree of solvent-solute interaction.


1959 ◽  
Vol 81 (24) ◽  
pp. 6472-6477 ◽  
Author(s):  
Emil J. Moriconi ◽  
William F. O'Connor ◽  
Lester P. Kuhn ◽  
Elizabeth A. Keneally ◽  
Frederick T. Wallenberger

10.1002/jcc.2 ◽  
1996 ◽  
Vol 17 (16) ◽  
pp. 1804-1819 ◽  
Author(s):  
Attila Kov�cs ◽  
Istv�n Kolossv�ry ◽  
G�bor I. Csonka ◽  
Istv�n Hargittai

2019 ◽  
Vol 58 (14) ◽  
pp. 9443-9451 ◽  
Author(s):  
Song Xu ◽  
Hyuk-Yong Kwon ◽  
Daniel C. Ashley ◽  
Chun-Hsing Chen ◽  
Elena Jakubikova ◽  
...  

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