Spin–spin coupling between proximate protons on neighbouring aromatic rings and between hydroxyl protons in 2,2′-dihydroxy-4-methoxybenzophenone. Coupling through the hydrogen bond

Schaefer, Ted; Chum, Kalvin

doi:10.1139/v76-316

Cited by 14 publications

(7 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A similar problem arises in the case of through-space coupling constants (usually 19 F-19 F). [74] Scheme 27 contains some old examples that have rarely been revisited though they deserve it: 55, [75] 56, [76] 57, [77] 58, [78] 59 [79] and 60. [80] Note that in compound 59 the coupling is across two hydrogen bonds.…”

Section: Intramolecular Hydrogen Bondsmentioning

confidence: 99%

A review with comprehensive data on experimental indirect scalar NMR spin–spin coupling constants across hydrogen bonds

Alkorta

Elguero

Денисов

2008

Magnetic Reson in Chemistry

View full text Add to dashboard Cite

show abstract

Section: Intramolecular Hydrogen Bondsmentioning

confidence: 99%

A review with comprehensive data on experimental indirect scalar NMR spin–spin coupling constants across hydrogen bonds

Alkorta

Elguero

Денисов

2008

Magnetic Reson in Chemistry

View full text Add to dashboard Cite

show abstract

“…0.02 Hz, is attributable to the proximity of the C-H-3 bond of the disubstituted aromatic ring and the ortho C-H bonds of the two phenyl groups. A similar coupling interaction occurs in a derivative of 2,2'-dihydroxybenzophenone, in which two intramolecular C=O-..HO hydrogen bonds constrain the phenyl groups to a conformation leading to close contacts of the hydrogen atoms of two C-H bonds on neighbouring aromatic rings (40). Models of DPPB imply that the conformation, in which the lone-pair lies near the plane of the disubstituted benzene and is oriented towards the forrnyl group, could have minimum distances as small as 1.3 A between the protons in the relevant C-H bonds.…”

Section: Structural Implications For 4~(~~~ P ) Arzd ~J(cho P )mentioning

confidence: 80%

¹H and ¹³C nuclear magnetic resonance studies of the conformational equilibrium of 2-(diphenylphosphino)benzaldehyde in polar and nonpolar solutions. Signs of the proximate coupling constants, ⁴J(CHO, ³¹P) and ³(¹³CHO, ³¹P)

Schaefer¹,

Sebastian²,

Schurko³

et al. 1993

Can. J. Chem.

Self Cite

View full text Add to dashboard Cite

The analyses of the 'H nuclear magnetic resonance spectra of 2-(dipheny1phosphino)benzaldehyde in CS2/C6Dlz and acetone-d6 solutions yield stereospecific coupling constants from which the populations of the 0-cis and 0-trans conformers are derived. The free energy differences favouring the 0-trans conformer at 300 K are 2.7 and 0.9 kJ/mol, in the polar and nonpolar solutions, respectively; in the crystal only the 0-cis conformer exists. The coupling constant, 'J(CHO, P), is estimated as -7.1(2) Hz in the 0-trans confomer and 3~(~~0 , P) as +29.4(1.3) Hz. Their magnitudes depend on the proximity of the C-H bond to the lone pair on phosphorus. "J(C, P) are reported for triphenylphosphine and for the benzaldehyde derivative as dilute solutions in the two solvents, demonstrating a significant solvent dependence for some of these coupling constants. Some simple relationships are proposed between "J(C, P) and the torsion angle about the C-P bond, estimates of the latter coming from AM1 and S T 0 3G MO computations. "J(C, P) are also sensitive to intrinsic ring substituent perturbations, as are the "J(H, P); for example, 5~(~, P) is negative in the disubstituted ring of 2-(dipheny1phosphino)benzaldehyde but positive in the phenyl groups. The "J(H, P) are also discussed with respect to their dependence on the torsion angles about the C-P bonds. It appears that the conformational properties of the aromatic rings in triphenylphosphine and its formyl derivative are very similar. Further, the phosphorus atom is polarized such that the carbonyl bond is attracted towards the positive region near phosphorus, and the C-H bond of the formyl group more towards the lone-pair region; the actual torsion angles represent a compromise between these attractive forces and the repulsive forces between bonds on neighbouring aromatic moieties. C N D 0 / 2 MO and INDO MO FPT computations of "J(C, P) and "J(H, P) are of mixed utility, although the former bear out the idea that the proximate O=C-H...lone-pair interaction dominates 3~(~~~,~) and 'J(CHO,P). dans la forme cristalline, seul le conformere 0-cis existe. On a CvaluC que la constante de couplage 'lJ(CH0, P) est de -7,1(2) Hz dans le conformere 0-trans alors que la constante 3~( C~0 , P) est de +29,4(1,3) Hz. Leurs amplitudes varient avec la distance entre la liaison C-H et la paire libre du phosphore. On rapporte les constantes "J(C, P) pour la triphenylphosphine et pour le derive benzaldehyde en solutions dilukes dans les deux solvants et on dkmontre ainsi une forte dependence sur le solvant pour quelques-unes de ces constantes. On propose quelques relations simples entre des "J(C, P) et l'angle de torsion autour de la liaison C-P Cvalue par des calculs OM AM1 et S T 0 3G. Comme c'est le cas pour les constantes "J(H, P), les constantes "J(C, P) sont aussi sensibles aux perturbations intrinseques causkes par les substituants du cycle; par exemple, la constante 'J(H, P) est negative dans le cycle disubstitue 2-diphCny1phosphino)-benzaldehyde, mais elle est positive dans les groupes ph...

show abstract

“…Coupling constants (of negative sign) between proximate protons have been measured in several less favorable situations. 40 Note that a negative sign arises for…”

Section: Analysis Of Fc Coupling In Ch· · ·Oh and Oh· · ·Oh Fragmentsmentioning

confidence: 99%

Density functional theory studies of transannular1H?1HJ-coupling in half-cage alcohols and rigid 1,3- and 1,4-diols: conformational dependencies and implications for intramolecular hydrogen bond detection in carbohydrates

Barfield¹,

Bergset²,

O’Leary³

2001

Magn. Reson. Chem.

View full text Add to dashboard Cite

Density functional theory (DFT) methods were used to investigate the conformational dependence of transannular H-H coupling constants in half-cage alcohols and cage diols. Finite perturbation theory (FPT) was used to obtain the Fermi contact (FC) contributions to scalar coupling constants in three halfcage alcohols and the OH· · ·OH coupling between hydroxyl groups sharing 1,4-and 1,3-intramolecular hydrogen bonds. Transannular CH· · ·OH coupling constants in the half-cage alcohols (inner OH) were obtained as a function of the dihedral angle defining the OH orientation. In comparison with the parent compound, chlorine substituents substantially modify the conformational dependence of the transannular H-H coupling and lead to observable coupling in the hexachloro compound. This is an unusual case, wherein the conformationally averaged coupling constants are quite different than those for the minimumenergy conformations. A −1.0 Hz scalar coupling is predicted between the very crowded protons in the half-cage acetate (outer OAc) in comparison with the experimental magnitude <1 Hz. In model 1,4-and 1,3-diols the coupling constants were obtained as functions of the analogous dihedral angles. The primary effects of hydrogen bonding are the stabilization of conformations in which the positive and negative contributions effectively cancel, thereby leading to small, observed values (e.g. ≤0.3 Hz). The DFT/FPT data for transannular coupling constants are consistent with a sum-over-states analysis for the direct mechanisms involving the two bonds containing the coupled nuclei rather than indirect mechanisms associated with oxygen lone pairs. Discussed here are the prospects of using OH· · ·OH scalar coupling for structural studies of carbohydrates.

show abstract

Spin–spin coupling between proximate protons on neighbouring aromatic rings and between hydroxyl protons in 2,2′-dihydroxy-4-methoxybenzophenone. Coupling through the hydrogen bond

Cited by 14 publications

References 10 publications

A review with comprehensive data on experimental indirect scalar NMR spin–spin coupling constants across hydrogen bonds

A review with comprehensive data on experimental indirect scalar NMR spin–spin coupling constants across hydrogen bonds

¹H and ¹³C nuclear magnetic resonance studies of the conformational equilibrium of 2-(diphenylphosphino)benzaldehyde in polar and nonpolar solutions. Signs of the proximate coupling constants, ⁴J(CHO, ³¹P) and ³(¹³CHO, ³¹P)

Density functional theory studies of transannular1H?1HJ-coupling in half-cage alcohols and rigid 1,3- and 1,4-diols: conformational dependencies and implications for intramolecular hydrogen bond detection in carbohydrates

Contact Info

Product

Resources

About

Spin–spin coupling between proximate protons on neighbouring aromatic rings and between hydroxyl protons in 2,2′-dihydroxy-4-methoxybenzophenone. Coupling through the hydrogen bond

Cited by 14 publications

References 10 publications

A review with comprehensive data on experimental indirect scalar NMR spin–spin coupling constants across hydrogen bonds

A review with comprehensive data on experimental indirect scalar NMR spin–spin coupling constants across hydrogen bonds

1H and 13C nuclear magnetic resonance studies of the conformational equilibrium of 2-(diphenylphosphino)benzaldehyde in polar and nonpolar solutions. Signs of the proximate coupling constants, 4J(CHO, 31P) and 3(13CHO, 31P)

Density functional theory studies of transannular1H?1HJ-coupling in half-cage alcohols and rigid 1,3- and 1,4-diols: conformational dependencies and implications for intramolecular hydrogen bond detection in carbohydrates

Contact Info

Product

Resources

About

¹H and ¹³C nuclear magnetic resonance studies of the conformational equilibrium of 2-(diphenylphosphino)benzaldehyde in polar and nonpolar solutions. Signs of the proximate coupling constants, ⁴J(CHO, ³¹P) and ³(¹³CHO, ³¹P)