Guest control of a hydrogen bond-catalysed molecular rotor

2017 ◽  
Vol 53 (92) ◽  
pp. 12469-12472 ◽  
Author(s):  
Gregory T. Rushton ◽  
Erik C. Vik ◽  
William G. Burns ◽  
Roger D. Rasberry ◽  
Ken D. Shimizu
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Intramolecular Hydrogen Bond ◽  
Molecular Rotor ◽  
Intramolecular Hydrogen

A molecular rotor is slowed by a hydrogen bonding guest that disrupts an intramolecular hydrogen bond, thus accelerating the rate of rotation.

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.

Intra- and inter-molecular hydrogen bonding in diphytanylglycerol phospholipids: an infrared spectroscopic investigation

1990 ◽  
Vol 68 (1) ◽  
pp. 266-273 ◽  
Author(s):  
L. C. Stewart ◽  
M. Kates ◽  
P. W. Yang ◽  
H. H. Mantsch
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Intramolecular Hydrogen Bond ◽  
Membrane Lipids ◽  
Head Group ◽  
Exact Nature ◽  
Oh Groups ◽  
Intramolecular Hydrogen ◽  
Phosphate Groups

A series of diphytanylglycerol phospholipids, i.e., diphytanylglycerol phosphate (PA), diphytanylglycerol phosphoglycerophosphate (PGP), the tri- and tetra-methyl derivatives of PGP, and the 2-deoxyglycerol analogue of PGP (dPGP) were studied by Fourier transform infrared spectroscopy. The use of the "deoxy" and methylated analogues of PGP, as well as that of PA and PGP of varying degrees of ionization, allowed the assignment of characteristic infrared bands associated with the phosphate groups. Analysis of these phosphate bands showed that at neutral pH, each of the two phosphate moieties in PGP is singly ionized, whereas in dPGP the phosphomonoester is doubly ionized. This is a consequence of the marked increase in the pK of one of the P-OH groups on the terminal phosphate of PGP (pK > 11), owing to the formation of an intramolecular hydrogen bond between the head group glycerol hydroxyl and the phosphate groups of PGP. Such an intramolecular hydrogen bond can not be formed by the dPGP analogue, and thus both negative charges in dPGP are located at the terminal phosphomonoester group. The O=P—OH groups of PGP also forms a network of intermolecular hydrogen bonds, the exact nature of which depends on concentration and degree of ionization. The possibility of a complex network of hydrogen bonds within (intramolecular) and between (intermolecular) anionic membrane lipids such as that found in PGP, is consistent with the hypothesis that these lipids function as proton-conducting pathways in membranes.Key words: phospholipids, infrared, hydrogen bonding, phosphatidylglycerophosphate, 2-deoxyphosphatidylglycerophosphate.

Hydrogen bonding, configuration and conformation of substituted α-oxo oximes and hydrazones

1979 ◽  
Vol 44 (8) ◽  
pp. 2494-2506 ◽  
Author(s):  
Otto Exner ◽  
Jorga Smolíková ◽  
Václav Jehlička ◽  
Ahmad S. Shawali
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Carbonyl Group ◽  
Intramolecular Hydrogen Bond ◽  
Benzene Solution ◽  
Dipole Moments ◽  
H Nmr ◽  
Intramolecular Hydrogen ◽  
Derivatives Of ◽  
Configuration And Conformation

Substituted 2-bromo-1-phenylglyoxal 2-phenylhydrazones IIIa-f exist in tetrachloromethane or benzene solutions prevailingly in E-configuration and in conformation A with an intramolecular hydrogen bond. The latter was evidenced by the N-H valence frequency at 3 290 cm-1 and by 1H NMR shifts with reference to derivatives without a carbonyl group - α-chlorobenzaldehyde phenylhydrazones V. From dipole moments of IIIa-d, measured in benzene solution, the contribution of the hydrogen bond (μH) was evaluated to 17 . 10-30 C m. This quantity is twice larger than in any other reported compound but the direction of the vector is as usual: approximately from H to N. In structurally similar derivatives of hydroxylamine, substituted 2-phenylglyoxylhydroximoyl chlorides IVa-d, no intramolecular hydrogen bond was detected; the dipole moments found were interpreted in terms of the Z-configuration and the prevailing conformation G.

scholarly journals Separation of planar rotamers through intramolecular hydrogen bonding in polysubstituted 5-nitrosopyrimidines

2014 ◽  
Vol 50 (94) ◽  
pp. 14892-14895 ◽  
Author(s):  
L. Čechová ◽  
E. Procházková ◽  
I. Císařová ◽  
M. Dračínský ◽  
Z. Janeba
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Intramolecular Hydrogen Bond ◽  
Chemical Species ◽  
Intramolecular Hydrogen Bonding ◽  
Nitroso Group ◽  
Group Orientation ◽  
Intramolecular Hydrogen

Unique isolation of pairs of planar rotamers, planamers, as chemical species differing only in nitroso group orientation, separable through the presence of a single intramolecular hydrogen bond, is reported.

Effects of the intramolecular hydrogen bond on intermolecular hydrogen bonding in hydroxybenzene-ether systems

1973 ◽  
Vol 77 (26) ◽  
pp. 3103-3106 ◽  
Author(s):  
J. N. Spencer ◽  
R. A. Heckman ◽  
R. S. Harner ◽  
S. L. Shoop ◽  
K. S. Robertson
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Intramolecular Hydrogen Bond ◽  
Intermolecular Hydrogen Bonding ◽  
Intramolecular Hydrogen

scholarly journals Computational evidence for intramolecular hydrogen bonding and nonbonding X···O interactions in 2'-haloflavonols

2012 ◽  
Vol 8 ◽  
pp. 112-117 ◽  
Author(s):  
Tânia A O Fonseca ◽  
Matheus P Freitas ◽  
Rodrigo A Cormanich ◽  
Teodorico C Ramalho ◽  
Cláudio F Tormena ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Quantum Theory ◽  
Intramolecular Hydrogen Bond ◽  
Natural Bond Orbital ◽  
Intramolecular Hydrogen Bonding ◽  
Nbo Analysis ◽  
Conformational Isomerism ◽  
Intramolecular Hydrogen ◽  
Stereoelectronic Interactions

The conformational isomerism and stereoelectronic interactions present in 2'-haloflavonols were computationally analyzed. On the basis of the quantum theory of atoms in molecules (QTAIM) and natural bond orbital (NBO) analysis, the conformer stabilities of 2'-haloflavonols were found to be dictated mainly by a C=O···H–O intramolecular hydrogen bond, but an unusual C–F···H–O hydrogen-bond and intramolecular C–X···O nonbonding interactions are also present in such compounds.

THE STUDY OF HYDROGEN BONDING AND RELATED PHENOMENA BY ULTRAVIOLET LIGHT ABSORPTION: PART III. THE STRENGTH OF THE DIMERIC HYDROGEN BOND IN SUBSTITUTED BENZOIC ACIDS AS A MEASURE OF ELECTRONIC AND STERIC INTERACTIONS

1960 ◽  
Vol 38 (5) ◽  
pp. 728-735 ◽  
Author(s):  
W. F. Forbes ◽  
A. R. Knight ◽  
D. L. Coffen
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Concentration Dependence ◽  
Intramolecular Hydrogen Bond ◽  
Light Absorption ◽  
Benzoic Acids ◽  
Steric Interactions ◽  
Substituted Benzoic Acids ◽  
Intramolecular Hydrogen ◽  
Methoxybenzoic Acid

The strength of the intermolecular (dimeric) hydrogen bond in substituted benzoic acids, as estimated from the observed concentration dependence of the ultraviolet absorption spectra, is found to vary with the nature and the position of the substituent. The effects of a number of substituents on the strength of the dimeric hydrogen bond can be rationalized in terms of the usual electronic and steric interactions. The data indicate that o-methoxybenzoic acid forms a stronger intramolecular hydrogen bond than o-fluorobenzoic acid.

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