✦ LIBER ✦

Correlation between 29Si NMR chemical shifts and mean SiO bond lengths for calcium silicates

✍ Scribed by Jørgen Skibsted; Jens Hjorth; Hans J. Jakobsen

Publisher: Elsevier Science
Year: 1990
Tongue: English
Weight: 391 KB
Volume: 172
Category: Article
ISSN: 0009-2614
DOI: 10.1016/0009-2614(90)85403-y

No coin nor oath required. For personal study only.

✦ Synopsis

The nine resonances in the hitherto unassigned %i magic-angle-spinning NMR spectrum of tricalcium silicate (C$) are tentatively assigned using a 6 versus dsro correlation between isotropic %i chemical shifts ( ) and mean Si-0 bond lengths (ds,,) observed for the a;-, B_, and y-dicalcium silicate (C,S) polymorphs. This results in a linear correlation, S(ppm) = -3167ds,d (A) $445.3 (R= -0.975, 12 data points), with increasing shielding corresponding to longer dsia bond distance in calcium monosilicates (Q"). The results and earlier established 6 versus dsi, correlations are discussed in relation to recent ab initio calculations of %Ii chemical shifts in isolated SiOi-tetrahedra.

📜 SIMILAR VOLUMES

Correlation between the isotropic 29Si c

Correlation between the isotropic 29Si chemical shifts and the mean silicon-oxygen bond lengths in silicates

✍ A.-R. Grimmer; R. Radeglia 📂 Article 📅 1984 🏛 Elsevier Science 🌐 English ⚖ 324 KB

Using known N3IR and structural data of solid silicates the linear correlation % = 1.187 X lo4 d(Si-0) -2014 between the isotropic z9Si NMR chemical shifts B (ppm) and the "isotropic" mean bond lengths d(Si-0) (nm) has been established. The results of semi-empirical calculations are in good agreemen

Correlation between individual SiO bond

Correlation between individual SiO bond lengths and the principal values of the 29Si chemical shift tensor in solid silicates

✍ A.-R. Grimmer 📂 Article 📅 1985 🏛 Elsevier Science 🌐 English ⚖ 416 KB

%I sluelding lensor data for sohd silrwres are compared =ilh structural data of the correspondmg SIO, tewahedra. demonstrating a hnear relallonship between mdlvldual SI-0 bond lengths and Ihe "bond dmxrlon related" shieldmg along the directions of the rour Si-0 bonds. This result is interpreted in r

High-resoluttin 29Si NMR in solid silica

High-resoluttin 29Si NMR in solid silicates: Correlations between shielding tensor and Si-O bond length

✍ A.-R. Grimmer; R. Peter; E. Fechner; G. Molgedey 📂 Article 📅 1981 🏛 Elsevier Science 🌐 English ⚖ 371 KB

Zetttralmstztut fhr attorgattrsche C/tetttte der Akadettrte der Wtssetrsciraftetz der DDR, I I99-Brrlur, DDR Reccwed 7-7 August 1980 "SI NhlR spectra of polycrystallmc Ca6 [SI~O,I(OH)~] and [(CH3)4N1 gS1g0x1 69H20 were measured usmg the cross polarlzatmn double-resonance technique Observed shleldmg

Correlation of SiOT (T = Si OR Al) ang

Correlation of SiOT (T = Si OR Al) angles and 29Si NMR chemical shifts in silicates and aluminosilicates. Interpretation by semi-empirical quantum-chemical considerations

✍ R. Radeglia; G. Engelhardt 📂 Article 📅 1985 🏛 Elsevier Science 🌐 English ⚖ 215 KB

The empirical correlation of 2gSi NMR chemical shifts 6 and the mean SIOT (T = Al. 5%) bond angles a in sibcates and alutiosili~tes is explained by a simple quantum-chemical model. A linear mrrelatlon 6 = 6 o + M + b cos a/(cos a -1) is derived, where n is the number of Al atoms in the Si(OSi)q \_n(

A semi-empirical quantum-chemical ration

A semi-empirical quantum-chemical rationalization of the correlation between SiOSi angles and 29Si NMR chemical shifts of silica polymorphs and framework aluminosilicates (zeolites)

✍ G. Engelhardt; R. Radeglia 📂 Article 📅 1984 🏛 Elsevier Science 🌐 English ⚖ 413 KB

The quantitative relationship between "52 chemical shifts 6 and SiOSi angles of framework silicates is rationalized by considering changes of the s character p of the osygen orbitals in the SiOSi D bond. A Linear correlation is established bctween 6 and p including 21 data points from 12 silica poly