Carbonates, Thiocarbonates, and the Corresponding Monoalkyl Derivatives: III. The 13C Chemical Shift Tensors in Potassium Carbonate, Bicarbonate and Related Monomethyl Derivatives

Stueber, Dirk; Orendt, Anita M.; Facelli, Julio C.; Parry, R. W.; Grant, David M.

doi:10.1006/snmr.2002.0061

Cited by 42 publications

(72 citation statements)

References 40 publications

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“…For example, we could use methods which include point charge arrays, either at actual ion positions with full ionic charges or as a array of more realistic atomic charges designed to reproduce the correct Madelung potential at the different sites. 22 It would also be possible to use band theoretical methods and plane wave basis sets to calculate the shieldings, as has now been done for a series of different materials. 23 We believe that for the problem at hand the use of local cluster models can also give good results, as we demonstrate below.…”

Section: Methodsmentioning

confidence: 99%

Calculation of19F and27Al NMR parameters for rosenbergite, AlF[F0.5(H2O)0.5]4·H2O, a possible model for Al hydroxyfluorides in solution

Tossell

Liu

2004

Magn. Reson. Chem.

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(19)F and (27)Al NMR chemical shifts are calculated for the F and Al atoms of the mineral rosenbergite, AlF[F(0.5)(H(2)O)(0.5)](4).H(2)O The structure of rosenbergite consists of infinite chains of F-corner-sharing Al[F(4)(H(2)O)(2)] octahedra and isolated water molecules. An F-centered molecular cluster of composition Al(2)F(3)(OH(2))(8) (3+) was initially used to model the mineral, with geometries taken both from the two different available x-ray crystal structures and from equilibrium geometries calculated at the 6-31G* B3LYP level (both with and without polarizable continuum solvation). Related Al(F)F(n) em leader clusters, with additional F(-) replacing H(2)O, were also studied. A larger Al-centered cluster model Al(3)F(4)(OH(2))(12) (5+) was also generated from one of the x-ray geometries and produced very similar bridging F shieldings but slightly different Al shieldings. The NMR shieldings were calculated using both HF and B3LYP GIAO methods, with 6-311+G(2df,p) basis sets, and the HF and B3LYP results averaged for the F shieldings as described in previous work. Calculated (19)F NMR shifts (relative to CCl(3)F) using this procedure were within a few ppm of experiment when either set of x-ray crystal structure coordinates was used, but differed by as much as 20 ppm for the energy-optimized geometries. Rosenbergite-like fragments with geometries optimized in water, simulated by a PCM, were used to model Al hydroxyfluoride species in solution. The (19)F NMR shifts for the bridging F atoms in several such model complexes are very similar to those usually attributed to monomeric species such as Al(OH(2))(5)F(2+) in solution, suggesting that the solution species are actually corner bridging oligomers. The F in the monomeric Al(OH(2))(5)F(2+) solution species is too strongly shielded by about 20 ppm to match the experimental peak usually assigned to it.

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Section: Methodsmentioning

confidence: 99%

Calculation of19F and27Al NMR parameters for rosenbergite, AlF[F0.5(H2O)0.5]4·H2O, a possible model for Al hydroxyfluorides in solution

Tossell

Liu

2004

Magn. Reson. Chem.

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“…Among the different point charge methods described in the literature, in this paper we consider the embedded ion method (EIM) 11 and the surface charge representation of the electrostatic embedding potential (SCREEP) 10 methods that have been developed independently in our laboratories. The EIM has been shown to improve the agreement between experimental and calculated chemical shifts in a wide variety of systems, ranging from ionic systems such as potassium carbonate and thiocarbonate 20 to systems with hydrogen bonding 12,21,22 and neutral systems with intermolecular Coulombic interactions such asˇ-HMX. 23 The SCREEP method, introduced originally by Stefanovich and Truong 24 to study catalysis, has more recently been applied to the calculation of chemical shielding by Solis et al 10 This method also shows improvements in agreement with experimental shifts comparable to those observed by the EIM method.…”

Section: Introductionmentioning

confidence: 98%

Modeling solid-state effects on NMR chemical shifts using electrostatic models

et al. 2004

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This paper presents a comparison of the embedded ion method (EIM) and the surface charge representation of the electrostatic embedding potential (SCREEP) method, two methods which can be used to calculate solid-state effects on NMR chemical shifts. The results in a selected group of compounds with known single-crystal solid-state NMR data and neutron diffraction structures, confirm that these effects are important in both (13)C and (15)N chemical shifts. The solid-state effects calculated by both methods are similar and of equal statistical quality when compared with the experimental data.

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“…The implications of the 13 C chemical shift tensor principal values and orientations for trigonal carbonate and thiocarbonate carbon atoms in potassium carbonate, trithiocarbonate, bicarbonate, and six related monomethyl derivatives, for the electronic structure of the anions in these compounds were recently investigated [1]. The accuracy with which 13 C chemical shift tensor calculations reproduce the experimental principal values in these ionic compounds depends significantly on two effects.…”

Section: Introductionmentioning

confidence: 98%

The 13C Chemical Shift Tensor Principal Values and Orientations in Dialkyl Carbonates and Trithiocarbonates

Stueber

Grant

2002

Solid State Nuclear Magnetic Resonance

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Carbonates, Thiocarbonates, and the Corresponding Monoalkyl Derivatives: III. The 13C Chemical Shift Tensors in Potassium Carbonate, Bicarbonate and Related Monomethyl Derivatives

Cited by 42 publications

References 40 publications

Calculation of19F and27Al NMR parameters for rosenbergite, AlF[F0.5(H2O)0.5]4·H2O, a possible model for Al hydroxyfluorides in solution

Calculation of19F and27Al NMR parameters for rosenbergite, AlF[F0.5(H2O)0.5]4·H2O, a possible model for Al hydroxyfluorides in solution

Modeling solid-state effects on NMR chemical shifts using electrostatic models

The 13C Chemical Shift Tensor Principal Values and Orientations in Dialkyl Carbonates and Trithiocarbonates

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