Solid-State 1H NMR Study of Structures and Dynamics of Proton Sites in Group II Salts of 12-Tungstophosphoric Acid and Related Compounds
| Autor: | Steven F. Dec, Andrew M. Herring |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Density matrix
Materials science 12-tungstophosphoric acid Group ii Solid-state 02 engineering and technology Limiting 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials symbols.namesake General Energy Proton NMR symbols Physical chemistry Density functional theory Physical and Theoretical Chemistry 0210 nano-technology Hamiltonian (quantum mechanics) |
| Zdroj: | The Journal of Physical Chemistry C. 122:15539-15557 |
| ISSN: | 1932-7455 1932-7447 |
| Popis: | The group II salts of 12-tungstophophoric acid were studied in the limiting state of hydration using a suite of 1H solid-state NMR experiments, theoretical analysis, and density functional theory (DFT) energy calculations. Various nonspinning (NS) 1H NS NMR, magic-angle spinning (MAS) 1H MAS NMR, and rotational-echo double-resonance (REDOR) 1H{31P} REDOR NMR experiments were performed. Chemical shift and spinning sideband patterns and comparison of 1H MAS two-pulse sequence NMR results with predictions of average Hamiltonian theoretical calculations definitively show that the limiting hydrated form of the group II salts of 12-tungstophosphoric acid contain only H+-protons and H2O-protons. Density matrix methods were used to derive expressions for the 1H NMR signal for a two-pulse NMR experiment as a function of the second pulse length under both NS and MAS conditions for H+-protons and H2O-protons. NMR structural parameters were obtained from the fit of theoretical expressions to the 1H NS two-pulse seque... |
| Databáze: | OpenAIRE |
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