Nuclear magnetic resonance studies of inorganic fluorides. V. Fluorosilanes

Johannesen, Rolf B.; Brinckman, F. E.; Coyle, T. D.

doi:10.1021/j100848a047

Cited by 82 publications

(14 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Unfortunately, experimental data are restricted to three species which contain four different silicon Table 3. sites (SiF 4 , Si 2 F 6 , and Si 3 F 8 ). 49 Experimental shifts are given with respect to SiF 4 . The shifts of these three compounds cover a range of ∼100 ppm, more than the whole set of silanes.…”

Section: Fluorosilanesmentioning

confidence: 99%

Performance of DFT for ²⁹Si NMR Chemical Shifts of Silanes

et al. 2000

View full text Add to dashboard Cite

The predictive power of DFT, HF, and MP2 29 Si NMR chemical shift calculations for silane molecules, including fluoro-and methylsilanes (Si n H 2n+2 (n ) 1, ..., 5), Si n F 2n+2 (n ) 1, ..., 3), and SiH m X 4-m (X ) F, CH 3 )) is compared. A systematic accumulation of error proportional to the number of hydrogen neighbors to silicon sites is observed for DFT for all applied exchange-correlation functionals, whereas MP2 is not affected by this problem. A proposed empirical correction scheme for DFT provides excellent agreement with experiment with any exchange-correlation functional employed in this study.

show abstract

Section: Fluorosilanesmentioning

confidence: 99%

Performance of DFT for ²⁹Si NMR Chemical Shifts of Silanes

et al. 2000

View full text Add to dashboard Cite

show abstract

“…The decrease of the intensity of the shorter wavelength peak with increasing concentration was most likely due to self -absorption since there was a small overlap of the absorption and emission spectra. 6 The relative fluorescence yields were obtained by integrating the area under each fluorescence spectra. Over the concentration range of this investiagtion, "Y between 2X 10--4 and 4X 10--2 , the fluorescence yields were the same for both solutes and essentially independent of the solute concentrations.…”

mentioning

confidence: 99%

Concentration Effects on the Fluorescence of PBD and Butyl-PBD

Horrocks

1967

The Journal of Chemical Physics

View full text Add to dashboard Cite

“…Again, 'J(F,P) is very likely negative in PF, (28), and its magnitude is 1404 Hz in the gas phase and 1423 Hz in CCI, solution (29). Similar remarks apply to 'J(F,S~) in SiF, (7,24,25).…”

Section: Depenclence Of J ( H F) On Van Der Ivnri1r Interactionsmentioning

confidence: 66%

“…Included are the proton c k m i c a l shifts the fact that In liquid CHF, the reorientational motion of the relative to internal TMS, 6,,, alld the approxilnate C H F , niolecule is efrectively isotropic (23) suggest that the cavity radii and possibly also the site factors of the two rnoleof the "lvent> when known. cules will be closely related, so that the solvent parameters, 'J(H,F) varies by I: ; , from 79.68 HZ in neat CHF3 derived by Rummens (17) (iu) The solvent effects on 'J(H,F) in CHF, are reminiscent of those found for 'J(F,Si) in SiF, (24). Raynes (25) shows that the solvent dependence of 'J(F,Si) in halomethane solvents is reproduced by the following bond parameters assigned to the solvents: j(C-F) = 0.18, j(C-H) = 1.23, j(C-CI) = 1.98 Hz.…”

Section: Depenclence Of J ( H F) On Van Der Ivnri1r Interactionsmentioning

confidence: 93%

Solvent-induced changes in ²J(H, F) for fluoroform via van der Waals interactions. Non-contact contributions to spin–spin coupling constants involving a proton?

Schaefer¹,

Hutton²,

Salman³

1979

Can. J. Chem.

View full text Add to dashboard Cite

. Can. J. Chem. 57, 1877 (1979). The spin-spin coupling between the proton and the fluorine nuclei, 'J, in fluoroform varies by 1% in a range of solvents. It is argued that 'J decreases algebraically as the van der Waals solute-solvent interactions increase in magnitude. Such a decrease is also observed for coupling constants which likely contain a substantial positive orbital contribution. If the van der Waals interactions perturb the spin-orbital term in J , then 'J in fluoroform may well contain orbital contributions, as recently calculated for 'J in methyl fluoride. In that event, the large discrepancies between observed 'J(H,F) values and those calculated by semiempirical theories of the contact term may be partially attributed to the neglect of orbital terms.TED SCHAEFER, HAROLD M. HUTTON et SALMAN R. SALMAN. Can. J. Chem. 57. 1877(1979). Le couplage spin-spin entre le proton et le fluor, 'J, du fluoroforme varie par 1% dans divers solvants. On suggere que 'J diminue d'une f a~o n algebrique au fur et a mesure d'une augmentation des interactions de van der Waals solute-solvant. On observe aussi une telle diminution des constantes de couplage qui contiennent probablement une contribution orbitalaire positive importante. Si les interactions de van der Waals perturbent le terme orbltalaire du spin de J , il est possible que la valeur 'J du fluoroforme puisse contenir des contributions orbitalaires semblables a celles calculCes recemment pour le ' J du fluorure de methyle. Alors, on pourrait attribuer en partie les grandes differences observees entre les valeurs de 'J(H,F) obsemtes et calculees par des theories semi-empiriques au fait que des termes orbitalaires ont etC omis.[Traduit par le journal]

show abstract

Nuclear magnetic resonance studies of inorganic fluorides. V. Fluorosilanes

Cited by 82 publications

References 9 publications

Performance of DFT for ²⁹Si NMR Chemical Shifts of Silanes

Performance of DFT for ²⁹Si NMR Chemical Shifts of Silanes

Concentration Effects on the Fluorescence of PBD and Butyl-PBD

Solvent-induced changes in ²J(H, F) for fluoroform via van der Waals interactions. Non-contact contributions to spin–spin coupling constants involving a proton?

Contact Info

Product

Resources

About

Nuclear magnetic resonance studies of inorganic fluorides. V. Fluorosilanes

Cited by 82 publications

References 9 publications

Performance of DFT for 29Si NMR Chemical Shifts of Silanes

Performance of DFT for 29Si NMR Chemical Shifts of Silanes

Concentration Effects on the Fluorescence of PBD and Butyl-PBD

Solvent-induced changes in 2J(H, F) for fluoroform via van der Waals interactions. Non-contact contributions to spin–spin coupling constants involving a proton?

Contact Info

Product

Resources

About

Performance of DFT for ²⁹Si NMR Chemical Shifts of Silanes

Performance of DFT for ²⁹Si NMR Chemical Shifts of Silanes

Solvent-induced changes in ²J(H, F) for fluoroform via van der Waals interactions. Non-contact contributions to spin–spin coupling constants involving a proton?