On the Use of Solomon Echoes in 27 Al NMR Studies of Complex Aluminium Hydrides.
Bodo ZibrowiusMichael FischerPublished in: ChemistryOpen (2023)
The quadrupole coupling constant C Q and the asymmetry parameter η have been determined for two complex aluminium hydrides from 27 Al NMR spectra recorded for stationary samples by using the Solomon echo sequence. The thus obtained data for KAlH 4 (C Q =(1.30±0.02) MHz, η=(0.64±0.02)) and NaAlH 4 (C Q =(3.11±0.02) MHz, η<0.01) agree very well with data previously determined from MAS NMR spectra. The accuracy with which these parameters can be determined from static spectra turned out to be at least as good as via the MAS approach. The experimentally determined parameters (δ iso , C Q and η) are compared with those obtained from DFT-GIPAW (density functional theory - gauge-including projected augmented wave) calculations. Except for the quadrupole coupling constant for KAlH 4 , which is overestimated in the GIPAW calculations by about 30 %, the agreement is excellent. Advantages of the application of the Solomon echo sequence for the measurement of less stable materials or for in situ studies are discussed.
Keyphrases
- density functional theory
- magnetic resonance
- molecular dynamics
- liquid chromatography
- high resolution
- mass spectrometry
- solid state
- tandem mass spectrometry
- electronic health record
- high performance liquid chromatography
- room temperature
- gas chromatography
- contrast enhanced
- simultaneous determination
- case control
- climate change
- ionic liquid
- artificial intelligence
- crystal structure
- virtual reality