Deuteron Quadrupole Coupling in D2O

Weissmann, Mariana

doi:10.1063/1.1726491

Cited by 37 publications

(3 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The 2 H( I = 1) ENDOR spectrum is more complicated than the corresponding 1 H spectrum since each line splits into a doublet due to the nuclear quadrupole interaction (see eq 2). For 2 H in an OD bond the maximum quadrupolar splitting is ∼0.3 MHz. , The 1 H and 2 H spectra can be conveniently compared by expanding the frequency scale of the 2 H spectrum by the factor γ H /γ D . When the hyperfine coupling is significantly larger than the quadrupole interaction a good correspondence in line positions is expected, except for small symmetrical shifts due to the quadrupole interaction which at this scale amounts to a maximum of ∼1.0 MHz.…”

Section: Resultsmentioning

confidence: 99%

W-Band ENDOR Investigation of the Manganese-Binding Site of Concanavalin A: Determination of Proton Hyperfine Couplings and Their Signs

et al. 2000

View full text Add to dashboard Cite

W-band (95 GHz) pulsed EPR and electron-nuclear double resonance spectroscopic techniques were used to investigate the manganese S1 binding site of the protein concanavalin A in a frozen solution and in a single crystal. 1 H ENDOR spectra were collected by using the Davies ENDOR sequence, whereas Mims ENDOR was applied to record 2 H ENDOR spectra. Different EPR transitions were selected by performing the ENDOR measurements at different magnetic fields within the EPR spectrum. This selection, combined with the large thermal polarization achieved at magnetic fields of ∼3.4 T at low temperatures, allowed the assignment of ENDOR signals to their respective M S manifolds, thus providing the sign of the hyperfine couplings. The exchangeable and nonexchangeable protons were differentiated by comparing 1 H and 2 H ENDOR spectra of a solution of the protein prepared in D 2 O and of crystals soaked in D 2 O. The two imidazole protons, located on the carbons flanking the Mn-bound nitrogen, are magnetically equivalent, situated 3.56 Å from the Mn 2+ and their hyperfine coupling is purely dipolar. The four protons of the two water ligands are all inequivalent, and four values of A | and A ⊥ were determined. All possible combinations of these values yield distances in the range of 2.67 to 3.24 Å and a iso between -1.13 and 1.37 MHz. By limiting a iso to positive values, only four distances remain, 2.67, 2.76, 2.99, and 3.24 Å, corresponding to the four Mn-H water distances.

show abstract

Section: Resultsmentioning

confidence: 99%

W-Band ENDOR Investigation of the Manganese-Binding Site of Concanavalin A: Determination of Proton Hyperfine Couplings and Their Signs

et al. 2000

View full text Add to dashboard Cite

show abstract

“…We therefore assume a constant value of the CDQC over the range of temperatures and pressures measured. However, with increasing temperature the 0 -D ... 0 distance will become larger [27,38], and this widening of the average Roo-distance must have an effect upon the CDQc [16,17,39,40]. It is trivial to predict qualitatively from an inspection of the results collected in Table 2 that raising the temperature should lead to an increase of the CDQc However, it is at present impossible to make any reliable quantitative estimate of this change.…”

Section: ) Estimate Of the Deuterium Quadrupole Coupling Constant ( mentioning

confidence: 99%

Pressure and Temperature Dependence of the Longitudinal Deuterium Relaxation Times in Supercooled Heavy Water to 300 MPa and 188 K

Lang

Lüdemann

1980

Ber Bunsenges Phys Chem

View full text Add to dashboard Cite

The longitudinal deuteron relaxation times T1 in heavy water have been determined at 15.4 MHz in the temperature range from T = 283 K to 188 K and up to pressures of 300 MPa. Between 283 K and 200 K all isotherms exhibit pronounced maxima of T1 in the pressure range between 150 MPa and 300 MPa. This maximum is most pronounced in the 242 K isotherm, where T1 increases more than fourfold from 17 ms at 0.1 MPa to 73 ms at 250 MPa. The 225 MPa isobar runs at 192 K through a minimum: T1 = 0.5 ms. Under the assumption of isotropic reorientation one derives from the minimum condition (ω0 ·τθ ⋍ 0.62) the deuteron quadrupole coupling constant for D2O to CDQC = 214 ± 12 kHz. The isobaric temperature dependence of the correlation times τθ can be described at p ≥ 200 MPa by the VTF‐equation. At p ≤ 100 MPa τθ increases faster with falling temperature than predicted by the VTF‐equation. In this range the isobars are best represented by an equation proposed by Speedy and Angell: The determination of τθ permits an estimate of the viscosity η and the self‐diffusion coefficient D for D2O in the supercooled range. Around T = 190 K and p = 225 MPa one gets η ⋍ 4 Pa · s and D ⋍ 6 · 10−9 cm2/s.

show abstract

“…Proton spectra are surveyed for a large number of aliphatic compounds in CCb, trifluoroacetic acid, and trifluoroacetic acid-sulfuric acid (1625 Careful measurement of proton shifts have been made for the liquid over its temperature range and for the gas a t various pressures in one study (936). Theoretical calculations of deuteron quadrupole coupling in free and hydrogen-bonded DzO lead to the conclusion that the major effect of H-bond formation is a lengthening of the 0-D bond (2129). Proton TI was studied from melting point to critical point temperatures for water in DzO and for ammonia in XD3 (1923 to critical point, indicates strong hydrogen bonding even a t high temperatures (1666).…”

Section: Other Solvekt Systems and Effectsmentioning

confidence: 99%

Nuclear magnetic resonance spectrometry

Heeschen¹

1968

Anal. Chem.

View full text Add to dashboard Cite

Deuteron Quadrupole Coupling in D2O

Cited by 37 publications

References 9 publications

W-Band ENDOR Investigation of the Manganese-Binding Site of Concanavalin A: Determination of Proton Hyperfine Couplings and Their Signs

W-Band ENDOR Investigation of the Manganese-Binding Site of Concanavalin A: Determination of Proton Hyperfine Couplings and Their Signs

Pressure and Temperature Dependence of the Longitudinal Deuterium Relaxation Times in Supercooled Heavy Water to 300 MPa and 188 K

Nuclear magnetic resonance spectrometry

Contact Info

Product

Resources

About