Studies of Hydrogen Bonding. Part V. The Intermolecular Hydrogen Bond Association of Amides with Phenol and Pentachlorophenol.

Gramstad, Thor; Fuglevik, Willy Johannes; Salmenperä, A.; Block-Bolten, A.; Toguri, J. M.; Flood, H.

doi:10.3891/acta.chem.scand.16-1369

Cited by 78 publications

(19 citation statements)

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“…Most carbonyl groups form somewhat weaker hydrogen bonds than ethers, but the OH frequency shift is still substantial. This rises to 6.0 kcaljmol for the same complex in carbon disulphide [86]. The bond strength within a series is a direct function of the basicity of the CO group, so that in p-nitrobenzaldehyde ~vOH is 117 cm -1, and this rises to 260 cm -1 in p-dimethylaminobenzaldehyde.…”

Section: O Bondsmentioning

confidence: 91%

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Associated XH Frequencies, the Hydrogen Bond

Bellamy¹

1980

The Infrared Spectra of Complex Molecules

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Section: O Bondsmentioning

confidence: 91%

“…Gramstad [59,86] gives extensive data on ~v and ~H values for the association of phenol with esters, ketones, aldehydes and amides. Most carbonyl groups form somewhat weaker hydrogen bonds than ethers, but the OH frequency shift is still substantial.…”

Section: O Bondsmentioning

confidence: 99%

Associated XH Frequencies, the Hydrogen Bond

Bellamy¹

1980

The Infrared Spectra of Complex Molecules

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“…were determined mostly by Gramstad and co-workers [49][50][51][52][53][54][55][56][57][58][59] in Norway, mainly between 1960 and 1969, using a near-infrared (NIR) spectroscopic method. This method employs the first overtone of the stretching O H vibration of phenol at 7052 cm −1 (1418 nm).…”

Section: Hydrogen-bond Basicity Scales: Early Workmentioning

confidence: 99%

Thermodynamic and Spectroscopic Scales of Hydrogen‐Bond Basicity and Affinity

2009

Lewis Basicity and Affinity Scales

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Water, alcohols, phenols, hydrogen halides, carboxylic acids, primary and secondary amines and amides, thiols, 1-alkynes and so on constitute a special class of Lewis acids. They all contain an XH group in which the hydrogen atom is bonded to an electronegative atom X and bears a partial positive charge. Therefore, the hydrogen is attracted, by means of electrostatic forces, toward high electron density regions, mainly the lone pairs of Lewis bases B, and a hydrogen bond (HB) X H · · · B is formed. In addition to this electrostatic interaction, there is a charge transfer from the base to the antibonding orbital σ * of the X H sigma bond. The respective contributions of electrostatic forces and charge transfer are a matter of debate. A modern electrostatic model of the hydrogen bond provides a near-quantitative description of structure and properties for a wide range of typical hydrogen bonds [1]. In contrast, NBO analysis suggests that charge transfer of n→σ * type is a characteristic feature of hydrogen bonding [2,3]. In any case, the existence of even a small charge transfer allows the hydrogen-bonding interaction to be considered as Lewis acid/base in nature [4]. The hydrogen-bond donor (HBD) XH is the electron acceptor and the hydrogen-bond acceptor (HBA) B is the electron donor. In the HSAB concept, HBDs are classified as hard Lewis acids [4] from the simple observation that the hydrogen bond is stronger when B is fluorine, oxygen or nitrogen than when it is iodine, sulfur or phosphorus, respectively.The reaction 4.1 of formation of a hydrogen bond between the molecules XH and B:can be used for the construction of a Lewis basicity scale, if a reference HBD is chosen and if the equilibrium constant K of the reaction is measured for a series of bases B under the same conditions: physical state (gas or solution in a given solvent), temperature and pressure. Such a scale, as logK or ∆G, must be named a hydrogen-bond basicity scale.

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“…The limiting condition is that mass and coupling effects are minimised by using compounds with similar structures. [49,50] We therefore completed our database on the hydrogen-bond basicity pK HB (in CCl 4 ) of esters [40] by studying two methyl acetates substituted by electron-attracting atoms on the ether moiety in order to mimic more closely the substituent effect of the positive nitrogen atom in ACh and norACh. The pK HB data reported in Table 6 can be converted into log K values in dichloromethane by using Equation (3), the linear free energy relationship (LFER) relevant to the family of carbonyl compounds studied herein.…”

Section: Hb Basicity Of the Nicotine And Ach Cationsmentioning

confidence: 99%

Hydrogen‐Bond Interactions of Nicotine and Acetylcholine Salts: A Combined Crystallographic, Spectroscopic, Thermodynamic and Theoretical Study

Arnaud

Berthelot

Evain

et al. 2007

Chemistry A European J

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The hydrogen-bond (HB) interactions of the monocharged active forms of nicotine and acetylcholine (ACh) have been compared theoretically by using density functional theory (DFT) calculations and experimentally on the basis of crystallographic observations and the measurement of equilibrium constants in solution. The 2,4,6-trinitrophenolate (picrate) counterion was used to determine the experimental HB basicity of the cations despite its potential multisite HB acceptor properties. The preferred HB interaction site of the ammonium picrate salts was determined from a survey of crystallographic data found in the Cambridge Structural Database (CSD) and is supported by theoretical calculations. Two distinct classes of ammonium groups were characterised depending on the absence (quaternary ammonium) or presence (tertiary, secondary and primary ammoniums) of an N(+)HO hydrogen bond linking the two ions. The crystal structure of nicotinium picrate was determined and compared with that of ACh. This analysis revealed the peculiar behaviour of the ammonium moiety of nicotinic acetylcholine receptor (nAChR) ligands towards the picrate anion. Dedicated methods have been developed to separate the individual contributions of the anion and cation accepting sites to the overall HB basicity of the ion pairs measured in solution. The HB basicities of the picrate anions associated with the two different ammonium classes were determined in dichloromethane solution by using several model ion pairs with non-basic ammonium cations. The experimental and theoretical studies performed on the nicotine and ACh cations consistently show the significant HB ability of the acceptor site of nAChR agonists in their charged form. Both the greater HB basicity of the pyridinic nitrogen over the carbonyl oxygen and the greater HB acidity of the N(+)H unit relative to N(+)CH could contribute to the higher affinity for nAChRs of nicotine-like ligands relative to ACh-like ligands.

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Studies of Hydrogen Bonding. Part V. The Intermolecular Hydrogen Bond Association of Amides with Phenol and Pentachlorophenol.

Cited by 78 publications

References 0 publications

Associated XH Frequencies, the Hydrogen Bond

Associated XH Frequencies, the Hydrogen Bond

Thermodynamic and Spectroscopic Scales of Hydrogen‐Bond Basicity and Affinity

Hydrogen‐Bond Interactions of Nicotine and Acetylcholine Salts: A Combined Crystallographic, Spectroscopic, Thermodynamic and Theoretical Study

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