Calculations of deuterium quadrupole coupling constants employing semiempirical molecular orbital theory

Barfield, Michael; Gottlieb, Hans Peter; Doddrell, David M.

doi:10.1063/1.436440

Cited by 28 publications

(3 citation statements)

References 50 publications

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“…A selection of the matrix elements is compared with results given by Barfield et al [35]. These results together with a 5000-point Diophantine integration are displayed in Table 11.…”

Section: Electric Field Gradientmentioning

confidence: 97%

Three‐dimensional numerical integration for electronic structure calculations

Boerrigter¹,

Velde²,

Baerends³

1988

Int J of Quantum Chemistry

775

388

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Two three-dimensional numerical integration schemes are presented for molecular integrands such as matrix elements of one-electron operators occurring in the Fock operator and expectation values of oneelectron operators describing molecular properties. The schemes are based on a judicious partitioning of space so that product-Gauss integration rules can be used in each region. Convergence with the number of integration points is such that very high accuracy (8-10 digits) may be obtained with a modest number of points. The use of point group symmetry to reduce the required number of points is discussed. Examples are given for overlap, nuclear potential, and electric field gradient integrals.

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“…A selection of the matrix elements is compared with results given by Barfield et al [35]. These results together with a 5000-point Diophantine integration are displayed in Table 11.…”

Section: Electric Field Gradientmentioning

confidence: 97%

Three‐dimensional numerical integration for electronic structure calculations

Boerrigter¹,

Velde²,

Baerends³

1988

Int J of Quantum Chemistry

775

388

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“…Of course, we expect the latter to be the larger. Both y0(D) and D0(H,F), the effective values in the free H F/D F molecule, will be reduced in magnitude if the H -F bond length increases on dimer formation, because it is known (Shea & Flygare 1982; Barfield et al 1978) that dy0(D)/dr = -3 3 kHz/0.01 A and, from (2), dD0/dr = 9.2 kHz/0.01 A.…”

Section: Rotational Spectrum and Properties Of H C N ---H F (B) The Lengthening Of The H-f Bond On Dimer Formation From Hyperjine Couplinmentioning

confidence: 99%

Spectroscopiċ investigations of hydrogen bonding interactions in the gas phase. X. Properties of the hydrogen-bonded heterodimer HCN∙ ∙ ∙HF determined from hyperfine coupling and centrifugal distortion effects in its ground-state rotational spectrum

Legon

Millen

Willoughby

1985

Proc. R. Soc. Lond. A

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The rotational spectra of six isotopic species of HCN∙ ∙ ∙HF in their vibrational ground states have been observed by pulsed-nozzle, Fourier-transform, microwave spectroscopy and have been analysed to yield the rotational constants B 0 , centrifugal distortion constants D J and various hyperfine coupling constants X i (D), X 3 ( 14 N) and D 4, 5 as follows (subscripts refer to the numbering scheme H (1) C (2) N (3) ∙ ∙ ∙H (4) F (5) ). isotopic species B 0 / MH Z D J /kH Z X i (D)/kH Z X 3 ( 14 N)/MH Z D 4, 5 (H, F)/kH Z HC 15 N∙ ∙ ∙HF 3573 5874(2) 6.97(2) ─ ─ –242(6) HC 15 N∙ ∙ ∙DF 3551.5110 6.83 269(4)( i = 4) ─ ─ HC 14 N∙ ∙ ∙HF 3591.1552 6.99 ─ –4.098(4) –218(6) HC 14 N∙ ∙ ∙DF 3569.6576 6.86 259(2)( i = 4) –4.096(1) ─ DC 15 N∙ ∙ ∙HF 3360.3549 5.85 186(5)( i = 1) ─ –244(4) DC 15 N∙ ∙ ∙DF 3338.0824 5.81 { 181(10) ( i = 1) ─ ─ 283(7) ( i = 4) The B 0 values lead to conclusions about the dimer geometry, the D J values allow the hydrogen bond stretching force constant k σ to be determined and the hyperfine coupling constants provide information about the internal dynamics of the subunits. An analysis of the D nuclear quadrupole coupling and H, F nuclear spin nuclear-spin coupling constants demonstrates that the H—F bond lengthens by 0.14 Å when the heterodimer HCN∙ ∙ ∙HF is formed. (1 Å = 10 –10 m = 10 –1 nm.)

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“…The only significant differences are that the COH angle has decreased by 0.7" and the C1-C7 (HO) bond length has decreased by 0.02 A in salicylaldehyde. At this level of theory there is no evidence for an 0-H bond as long as 1.15 A, apparently foynd in the 3-methoxy derivative (33,34) or as long as 1.16 A, suggested for salicylaldehyde itself (35,36). In a correlation of 0-H and 0 --.…”

Section: St0 3g Mo Calculations Of Geometry and Energymentioning

confidence: 99%

Spin–spin coupling between hydroxyl and aldehydic protons in some salicylaldehyde derivatives. Correlation with the hydroxyl proton chemical shift

Schaefer¹,

Sebastian²,

Laatikainen³

et al. 1984

Can. J. Chem.

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. J. Chem. 62, 326 (1984).'H nmr spectral parameters are reported for salicylaldehyde and 15 of its derivatives in dilute CCI, solutions. In those compounds in which sufficiently large substituents are placed ortho to either of the functional groups or in which substituents enhance the charge density in the carbonyl group, a positive spin-spin coupling is observed between the two sidechain protons. This coupling, formally over five bonds, correlates with the chemical shift of the hydroxyl proton. ' The coupling mechanism is discussed from various viewpoints. S T 0 3G MO calculations give an optimized planar structure for salicylaldehyde. Nonplanar structures are less stable than the planar form. The energy of the hydrogen bond in salicylaldehyde lies near 30 kJ/mol and increases to 36 kJ/mol in the 4,6-dimethoxy derivative. Other small long-range spin-spin coupling constants in these compounds are also discussed.TED SCHAEFER, RUDY SEBASTIAN, REINO LAATIKAINEN et SALMAN R. SALMAN. Can. J. Chem. 62, 326 (1984).On rapporte les paramtttres spectraux du salicylaldChyde et de 15 de ses dCrivCs en solution diluCe dans le CCL. On observe un couplage spin-spin positif entre les protons des chaines laterales des composCs dans lesquels des substituants assez volumineux sont en position ortho par rapport aux groupes fonctionnels ou dans lesquels les substituants augmentent la densite de charge du groupe carbonyle. Ce couplage, formellement Ctabli h travers plus de 5 liaisons, est en accord avec les dCplacements chimiques du proton hydroxylique. On discute du mtcanisme du couplage h partir de diverses considkrations. Les calculs S T 0 3G OM donnent une structure plane optimisCe pour le salicylaldChyde. Les structures non planes sont moins stables que la forme plane. L'Cnergie de la liaison hydrogttne du salicylaldChyde est d'environ 3 0 kJ/mol et augmente jusqu'h 36 kJ/mol dans le dCrivk dimCthoxy-4,6. On discute Cgalement d'autres faibles constantes d e couplage spin-spin h longue distance observts dans ces composCs.[Traduit par le journal] Introduction At 308 K the chemical shift of the hydroxyl proton in phenol, FjOH/(ppm), at infinite dilution in CC1, is 4.26 (1). In salicylaldehyde FjOH is near 11 (2), reflecting the presence of a normal3 intramolecular hydrogen bond in 1, whose energy has been variously estimated as lying between 3.3 and 35.2 kJ/mol (3-8).

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Calculations of deuterium quadrupole coupling constants employing semiempirical molecular orbital theory

Cited by 28 publications

References 50 publications

Three‐dimensional numerical integration for electronic structure calculations

Three‐dimensional numerical integration for electronic structure calculations

Spectroscopiċ investigations of hydrogen bonding interactions in the gas phase. X. Properties of the hydrogen-bonded heterodimer HCN∙ ∙ ∙HF determined from hyperfine coupling and centrifugal distortion effects in its ground-state rotational spectrum

Spin–spin coupling between hydroxyl and aldehydic protons in some salicylaldehyde derivatives. Correlation with the hydroxyl proton chemical shift

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