Empirical calculations of 29Si NMR chemical shielding tensors: A partial charge model investigation of hydrolysis in organically modified alkoxy silanes

2000 ◽  
Vol 2 (1) ◽  
pp. 23-28 ◽  
Author(s):  
Todd M. Alam ◽  
Marc Henry
Keyword(s):  
Model Investigation ◽  
29Si Nmr ◽  
Partial Charge ◽  
Chemical Shielding ◽  
Charge Model ◽  
Organically Modified ◽  
Partial Charge Model ◽  
Shielding Tensors

Electronegativity-Based Computation of 29Si Chemical Shifts

1992 ◽  
Vol 271 ◽  
Author(s):  
Henry. M ◽  
Gerardin. C ◽  
Taulelle. F
Keyword(s):  
Chemical Shifts ◽  
Sol Gel ◽  
Partial Charge ◽  
Detailed Structure ◽  
Mean Excitation Energy ◽  
Charge Model ◽  
Partial Charges ◽  
Nuclear Shielding ◽  
Partial Charge Model ◽  
The Mean

ABSTRACTThe Partial Charge Model has been modified to take into account the detailed structure of any molecular sol-gel precursors or inorganic solid networks. Starting from these structure-dependent partial charges, the classical theory of nuclear shielding is applied to compute the electronic cloud compacity <r-3>p, the population unbalance Pu and also the mean excitation energy ΔE. With these three parameters it is possible to explain the chemical shifts variations, spanning from +40 down to -140 ppm, of more than 50 precursors. Depending on the ligands, the well-known upside-down U-curves for series SiXnY4-n (n=0‥4) can be ascribed either to the population unbalance term Pu or to a competition between the two other terms <r-3>p and ΔE.

An effective partial charge model for bulk and surface properties of cubic ZrO2, Y2O3 and yttrium-stabilised zirconia

2019 ◽  
Vol 21 (46) ◽  
pp. 25635-25648
Author(s):  
Thomas S. Hofer ◽  
Franziska M. Kilchert ◽  
Bagas A. Tanjung
Keyword(s):  
Surface Properties ◽  
Partial Charge ◽  
Interaction Potentials ◽  
Charge Model ◽  
Partial Charges ◽  
Partial Charge Model

Novel interaction potentials using effective partial charges are derived, leading to a superior description of bulk and surface properties.

An Experimental and Theoretical Investigation of the Chemical Shielding Tensors of13Cαof Alanine, Valine, and Leucine Residues in Solid Peptides and in Proteins in Solution

2001 ◽  
Vol 123 (42) ◽  
pp. 10362-10369 ◽  
Author(s):  
Robert H. Havlin ◽  
David D. Laws ◽  
Hans-Marcus L. Bitter ◽  
Lori K. Sanders ◽  
Haihong Sun ◽  
...  
Keyword(s):  
Theoretical Investigation ◽  
Chemical Shielding ◽  
Shielding Tensors
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