The Use of the Chemical Shift Parameter for Study of Intramolecular Hydrogen Bonds

Allan, E. A.; Reeves, L. W.

doi:10.1021/j100810a010

Cited by 72 publications

(21 citation statements)

References 1 publication

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“…Moreover, the F---H and F---0 internuclear separations are greater than the values for which intramolecular bonding interactions are observed in the protonated fluoroacetones (Table 2). Our calculations support the claim (17) that there is no hydrogen bonding in o-fluorophenol due to the larger internuclear separation between fluorine and the carbonyl proton. It is interesting to note that in the case of CH2FCOHCH3+, p(rc) of the F---H interaction at the 4-31GflSTO-3G level is more than double that of the F---0 interaction at the 4-3 1G//4-3 1 6 level.…”

Section: Methodssupporting

confidence: 86%

Analysis of intramolecular hydrogen bonding in terms of the topological properties of the charge density. The protonated fluoroacetones

Choi¹,

Boyd²

1986

Can. J. Chem.

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. 64, 2042 (1986). A new method for the analysis of intramolecular hydrogen bonding is proposed and applied to the equilibrium structures of the protonated fluoroacetones. The method, based on a theory of molecular structure due to Bader, uses the topological properties of the charge density to elucidate the types of interactions within a molecule of interest. The calculations show a strong basis set dependence. In particular, the STO-3G optimized geometries exhibit intramolecular hydrogen bonding between a fluorine substituent and the carbonyl proton, whereas some calculations with geometries optimized at the 4-31G and 6-31G* levels indicate a direct bonding interaction between the fluorine and oxygen atoms. Two types of catastrophe point, namely conflict and bifurcation, are possible in protonated monofluoroacetone. Only the latter was located in the present calculations.

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Section: Methodssupporting

confidence: 86%

Analysis of intramolecular hydrogen bonding in terms of the topological properties of the charge density. The protonated fluoroacetones

Choi¹,

Boyd²

1986

Can. J. Chem.

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“…{ dp L I dp L 2 d<92) dp (2) The first term in (2) is the 'static term' and represents the effect of pressure on the static lattice (due to com pression); the second term, the 'dynamic term', respresents the effect of pressure on the amplitudes of the tor sional oscillations.…”

Section: Resultsmentioning

confidence: 99%

“…In contrast to chloroanisoles, phenols have the hydroxyl group. Orthochlorophenols exhibit both inter-and intramolecular hydro gen bonding, the ortho-chlorine playing an important role [1][2][3][4][5][6][7][8][9]. Chloroanisoles do not exhibit any hydrogen bonding [1][2][3][4][5][6][7][8][9][10].…”

Section: Introductionmentioning

confidence: 99%

Pressure Dependence of the Chlorine NQR in Three Solid Chloro Anisoles

Suresh

Ramesh

Rao

et al. 2001

Zeitschrift Für Naturforschung A

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The 35C1 Nuclear Quadrupole Resonance (NQR) frequency ( V q ) and spin lattice relaxation time (T{) in the three anisoles 2,3,4-trichloroanisole, 2,3,6-trichloroanisole and 3,5-dichloroanisole have been measured as a function of pressure upto 5.1 kbar at 300 K, and the data have been analysed to estimate the temperature coefficients of the NQR frequency at constant volume. All the three com pounds show a non linear variation of the NQR frequency with pressure, the rate of which is positive and decreases with increasing pressure. In case of 3,5-dichloroanisole the value becomes negative in the higher range of pressure studied. The spin lattice relaxation time T{ in all the three compounds shows a weak dependence on pressure, indicating that the relaxation is mainly due to the torsional motions.

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“…X distance is fixed by the system. On the basis of n.m.r, spectroscopy Allan and Reeves (21) suggest that the flourine atom is too small to lead to measurable stability of a cis-isomer in o-fluorophenol. Similarly, the ultraviolet spectra of the B-bands of o-fluorophenol (22) and o-fluorobenzoic acid (23) indicate the absence of strong intramolecular hydrogen bonds in these compounds.…”

Section: *For 2-jluoroethanol These Band Widths Were Obtained Front Tmentioning

confidence: 99%

Spectroscopic Studies of Alcohols: Ii. The Conformation of 2-Haloethanols in Carbon Tetrachloride Solution

Krueger¹,

Mettee²

1964

Can. J. Chem.

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Of the five conformers predicted for 2-haloethanols, only tm70 (halogen and OH trails and gauche) can be positively identified by high resolution infrared spectroscopy. From the temperature depelldence of the relative intensities of the fundamental OH stretching bands of the trans and gauche forms of the compouilds XCHZCHaOH, where X = F, C1, Br, and I, the gauche conformers are shown to be energetically favored in dilute carbon tetrachloride solution, with enthalpy differences between the two conforlners of 2.072~0.53, 1.20&0.09, 1.26f 0.08, and 0.8110.09 Ircal/mole respectively. Equilibrium constants and the conformational free energy and eiitropy differences are reported. Inter-and intra-molecular OH. . .X hydrogen-bond interactions are found to be similar in that the enthalpy increases in the order X = I < Br < C1 < F, and is linearly related to a decrease in the fundamental OH band shift, in contrast to the Badger-Bauer relationship. The ~nolecular and thermodyliamic factors governing conformatioiial equilibria involving intramolecular hydrogen bonds are discussed. IYTRODUCTIONSince 1936, when the thermodynamic properties of hydrocarbons calculated on the basis of restricted internal rotation about a single bond were first shown to be in agreement with the experimental values ( I ) , a large amount of inforination has been accumulated about the nature of the potential ininirna which exist for those molecular conforinations in which the bonds to the atonls on the axis of rotation have taken up a staggered orientation (2). As the barriers t o rotation are usually relatively low, aliphatic hydrocarbons and their derivatives exhibit a high degree of conformational heterogeneity in the gaseous or liquid state. In the crystalline state such rotational freedom is lost, and the rnolecule is frozen in its no st stable form. RIuch of the early work in this field involved halogenated ethanes.Recently Xuhn, Luettke, and Aleclte (3).showed that in 2-haloethanols in CC14 solution only two conforn~ers (trans and gauche) could be identified by means of infrared spectra in the OH stretching region obtained with a pris~n spectrophotometer. The two gauche forms in the equilibria are inirror inlages and thus spectros~opically equivalent. The low frequency vex con~ponent is assigned to the gauche forms. NL'Funck's general treatment of rotational isoinerisill in linear polymethylene chains X-(CH2),-Y (4) predicts nine rotational isomers for XCHzCH20H, taking into V a p e r presented at the @tlz Annual

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The Use of the Chemical Shift Parameter for Study of Intramolecular Hydrogen Bonds

Cited by 72 publications

References 1 publication

Analysis of intramolecular hydrogen bonding in terms of the topological properties of the charge density. The protonated fluoroacetones

Analysis of intramolecular hydrogen bonding in terms of the topological properties of the charge density. The protonated fluoroacetones

Pressure Dependence of the Chlorine NQR in Three Solid Chloro Anisoles

Spectroscopic Studies of Alcohols: Ii. The Conformation of 2-Haloethanols in Carbon Tetrachloride Solution

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