Zibrowius Bodo, Fischer Michael
45468, Mülheim an der Ruhr, Germany.
Crystallography & Geomaterials Research, Faculty of Geosciences, University of Bremen, Klagenfurter Straße 2-4, 28359, Bremen, Germany.
ChemistryOpen. 2024 Jan;13(1):e202300011. doi: 10.1002/open.202300011. Epub 2023 Jun 14.
The quadrupole coupling constant C and the asymmetry parameter η have been determined for two complex aluminium hydrides from Al NMR spectra recorded for stationary samples by using the Solomon echo sequence. The thus obtained data for KAlH (C =(1.30±0.02) MHz, η=(0.64±0.02)) and NaAlH (C =(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 , C 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 , 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.
通过使用所罗门回波序列，对固定样品记录的铝核磁共振谱，测定了两种复杂氢化铝的四极耦合常数C和不对称参数η。由此获得的KAlH（C =(1.30±0.02) MHz，η=(0.64±0.02)）和NaAlH（C =(3.11±0.02) MHz，η<0.01）的数据与先前通过魔角旋转核磁共振谱测定的数据非常吻合。结果表明，从静态谱中确定这些参数的精度至少与通过魔角旋转方法的精度一样好。将实验测定的参数（δ、C和η）与通过密度泛函理论-含规范投影增强波（DFT-GIPAW）计算获得的参数进行了比较。除了KAlH的四极耦合常数在GIPAW计算中被高估约30%外，两者吻合得非常好。讨论了所罗门回波序列在测量不太稳定的材料或原位研究中的应用优势。
