Pillar[5]arenes with an introverted amino group: a hydrogen bonding tuning effect

2013 ◽  
Vol 11 (2) ◽  
pp. 248-251 ◽  
Author(s):  
Lei Chen ◽  
Zhiming Li ◽  
Zhenxia Chen ◽  
Jun-Li Hou
Keyword(s):  
Hydrogen Bonding ◽  
Amino Group ◽  
Group A

Special transport and neurological significance of two amino acids in a configuration conventionally designated as D.

1994 ◽  
Vol 196 (1) ◽  
pp. 297-305 ◽  
Author(s):  
H N Christensen ◽  
A A Greene ◽  
D K Kakuda ◽  
C L MacLeod
Keyword(s):  
Amino Acids ◽  
Receptor Site ◽  
Amino Group ◽  
Carboxylate Group ◽  
Gamma Aminobutyric Acid ◽  
Imino Group ◽  
Group A ◽  
The Central Nervous System ◽  
Lower Homolog ◽  
Alpha Amino Acid

We point out an ability of certain amino acids to be recognized at a biological receptor site as though their amino group bore, instead of an alpha relationship to a carboxylate group, a beta, gamma or delta relationship to the same or a second carboxylate group. For aspartate, the unbalanced position of its amino group between a pair of carboxylates allows its occasional biorecognition as a beta-rather than as an alpha-amino acid, whereas for proline and its homologs, their cyclic arrangement may allow the imino group, without its being replicated, to be sensed analogously as falling at either of two distances from the single carboxylate group. The greater separation might allow proline to be seen as biologically analogous to gamma-aminobutyric acid. This more remote positioning of the imino group would allow the D-form of both amino acids to present its amino group in the orientation characteristic of the natural L-form. The dual modes of recognition should accordingly be signalled by what appears to be low stereospecificity, actually due to a distinction in the enantiorecognition of the two isomers. Competing recognition for transport between their respective D- and L-forms, although it does not prove that phenomenon, has been shown for proline and, significantly, even more strongly for its lower homolog, 2-azetidine carboxylate. Such indications have so far revealed themselves rather inconspicuously for the central nervous system binding of proline, reviewed here as a possible feature of a role suspected for proline in neurotransmission.

scholarly journals Crystal structure of 2-(2,4-diphenyl-3-azabicyclo[3.3.1]nonan-9-ylidene)acetonitrile

2015 ◽  
Vol 71 (10) ◽  
pp. o792-o793
Author(s):  
K. Priya ◽  
K. Saravanan ◽  
S. Kabilan ◽  
S. Selvanayagam
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Crystal Packing ◽  
Van Der Waals ◽  
Van Der Waals Forces ◽  
Chair Conformation ◽  
Equatorial Orientation ◽  
Amino Group ◽  
Phenyl Rings

In the title 3-azabicyclononane derivative, C22H22N2, both the fused piperidine and cyclohexane rings adopt a chair conformation. The phenyl rings attached to the central azabicylononane fragment in an equatorial orientation are inclined to each other at 23.7 (1)°. The amino group is not involved in any hydrogen bonding, so the crystal packing is stabilized only by van der Waals forces.

Hydrogen-bonding patterns in the cocrystal 2,4-diamino-6-phenyl-1,3,5-triazine–sorbic acid (1/1)

2007 ◽  
Vol 63 (11) ◽  
pp. o4450-o4451 ◽  
Author(s):  
Kaliyaperumal Thanigaimani ◽  
Packianathan Thomas Muthiah ◽  
Daniel E. Lynch
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Sorbic Acid ◽  
Carboxyl Group ◽  
Amino Group ◽  
Acid Molecule ◽  
Asymmetric Unit ◽  
Graph Set ◽  
Bonding Patterns

In the title cocrystal, C9H9N5·C6H8O2, the asymmetric unit contains one 2,4-diamino-6-phenyl-1,3,5-triazine molecule and a sorbic acid molecule. The triazine molecules are base-paired [with a graph set of R 2 2(8)] on either side via N—H...N hydrogen bonds, forming a supramolecular ribbon along the c axis. Each triazine molecule interacts with the carboxyl group of a sorbic acid molecule via N—H...O and O—H...N hydrogen bonds, generating R 2 2(8) motifs. The supramolecular ribbons are interlinked by N—H...O hydrogen bonds involving the 2-amino group of the triazine molecules and the carboxyl O atom of the sorbic acid molecule.

Hydrogen Bonding in organic compounds. 1. o-Nitroanilines

1958 ◽  
Vol 11 (4) ◽  
pp. 513 ◽  
Author(s):  
LK Dyall ◽  
AN Hambly
Keyword(s):  
Hydrogen Bonding ◽  
Nitro Group ◽  
Organic Compounds ◽  
Intramolecular Hydrogen Bonding ◽  
Amino Group ◽  
Infra Red ◽  
Sterically Hindered ◽  
Intramolecular Hydrogen

The infra-red spectra of o-nitroanilines do not indicate any intramolecular hydrogen bonding unless there are nitro groups in both positions 2 and 6 to the amino group. An examination of the literature shows that there is no unambiguous evidence from other sources of such bonding in simple o-nitroanilines. An explanation is given of the variation of the stretching frequencies of the nitro group in sterically hindered compounds and in those with electron-donating ortho- and para-substituents.

Proton Magnetic Resonance Spectra of Some Amphetamines and Related Compounds and Observations on Rotamer Populations

1971 ◽  
Vol 49 (19) ◽  
pp. 3143-3151 ◽  
Author(s):  
K. Bailey ◽  
A. W. By ◽  
K. C. Graham ◽  
D. Verner
Keyword(s):  
Hydrogen Bonding ◽  
Phenyl Ring ◽  
Proton Magnetic Resonance ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Side Chain ◽  
Amino Group ◽  
Ortho Position ◽  
Electronic Effects ◽  
Related Compounds

Data from the p.m.r. spectra of β-amino-, β-aminohydrochloride-, β-hydroxy-, and β-nitro-α-phenyl-propanes having methyl or methoxy substituants on the phenyl ring (37 compounds in all) are presented. The α and β protons of the side-chain give a pattern usually analyzable as ABX. The data are discussed in terms of correlations of coupling constants and chemical shifts with electronegativity of the substituent groups, steric and electronic effects, and apparent changes in rotamer populations. Hydrogen-bonding between the amino group of amphetamines and a methoxyl function at the ortho position in the phenyl ring is indicated for the salts but not the free bases.

THE STUDY OF HYDROGEN BONDING AND RELATED PHENOMENA BY SPECTROSCOPIC METHODS: PART VIII. THE ULTRAVIOLET AND INFRARED SPECTRA OF SOME 2,4-DINITRODIPHENYLAMINES

1964 ◽  
Vol 42 (12) ◽  
pp. 2674-2683 ◽  
Author(s):  
A. Balasubramanian ◽  
J. B. Capindale ◽  
W. F. Forbes
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Spectral Data ◽  
Intramolecular Hydrogen Bond ◽  
Infrared Spectra ◽  
Positive Charge ◽  
Spectroscopic Methods ◽  
Amino Group ◽  
Strong Type ◽  
Intramolecular Hydrogen

The ultraviolet spectra of a number of 2,4-dinitrodiphenylamines suggest that these compounds are generally non-planar in a number of different solvents. The infrared and ultraviolet spectral data in different solvents also suggest that an intramolecular hydrogen bond is present in these molecules, at least in inert solvents. There is evidence that a p-nitro substituent is necessary to increase the positive charge on the amino group sufficiently to permit it to form this fairly strong type of hydrogen bond.

scholarly journals 3,5-Dinitrosalicylic Acid in Molecular Assembly. III. Proton-Transfer Compounds of 3,5-Dinitrosalicylic Acid with Polycyclic Aromatic and Heteroaromatic Amines, and Overall Series Structural Systematics

2007 ◽  
Vol 60 (4) ◽  
pp. 264 ◽  
Author(s):  
Graham Smith ◽  
Urs D. Wermuth ◽  
Peter C. Healy ◽  
Jonathan M. White
Keyword(s):  
Hydrogen Bonding ◽  
Proton Transfer ◽  
Crystal Structures ◽  
Molecular Assembly ◽  
Lewis Base ◽  
Amino Group ◽  
Π Interactions ◽  
Hydrogen Donors ◽  
Polycyclic Aromatic ◽  
Proton Transfer Compounds

The crystal structures of the 1:1 proton-transfer compounds of 3,5-dinitrosalicylic acid (dnsa) with a series of common polycyclic aromatic and heteroaromatic amines (quinoline, 1-naphthylamine, 1,2,3,4-tetrahydroquinoline, quinaldic acid, benzimidazole, 1,10-phenanthroline, and 2,2′-bipyridine) have been determined and the hydrogen-bonding associations in each analyzed. The compounds are [(C9H8N)+(dnsa)–] 1, [(C10H10N)+(dnsa)–] 2, [(C9H12N)+(dnsa)–] 3, [(C10H8NO2)+(dnsa)–] 4, [(C7H7N2)+(dnsa)–] 5, [(C12H9N2)+(dnsa)–] 6, and [(C10H9N2)+(dnsa)–] 7. In all compounds, protonation of either the substituent amino group or the hetero-N of the Lewis base occurs, with subsequent hydrogen bonding via this and other hydrogen donors variously to the carboxylate, phenate, and nitro oxygen acceptors of the dnsa anions. The result is the formation of primary N+–H···O associations which with secondary peripheral interactions, which within this set of compounds includes an increased incidence of aromatic C–H···O associations, give framework polymer structures. In three of the compounds [1, 4, and 6], cation–anion π–π interactions are also found. The completion of this series of compounds has now allowed the categorization of the molecular assembly modes in the proton-transfer compounds of 3,5-dinitrosalicylic acid.

Intramolecular Hydrogen Bonding in Mononitronaphthylamines

1960 ◽  
Vol 13 (4) ◽  
pp. 456
Author(s):  
A Bryson ◽  
RL Werner
Keyword(s):  
Hydrogen Bonding ◽  
Carbon Tetrachloride ◽  
Intramolecular Hydrogen Bonding ◽  
Amino Group ◽  
Amino Groups ◽  
Solute Interaction ◽  
Intramolecular Hydrogen

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.

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