Theoretical investigation of F-19 NMR chemical shielding of alkaline-earth-metal and alkali-metal fluorides

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	Theoretical investigation of F-19 NMR chemical shielding of alkaline-earth-metal and alkali-metal fluorides
	Cai, S. H. ; Chen, Z. ; Wan, H. L. ; Chen Z(陈忠)
刊名	http://dx.doi.org/10.1021/jp013503f
	2002-02-14
关键词	DENSITY-FUNCTIONAL THERMOCHEMISTRY RELATIVISTIC EFFECTIVE POTENTIALS SPIN-ORBIT OPERATORS AB-INITIO SHIFTS CALCULATIONS CORRELATION-ENERGY EXACT-EXCHANGE ELECTRON-GAS BASIS-SETS DFT-GIAO
英文摘要	The F-19 NMR chemical shieldings of solid-state alkaline-earth-metal fluorides MF2 (M = Be, Mg, Ca, Sr, Ba) and alkali-metal fluorides MF (M = Li, Na, K, Rb, Cs) were systematically studied by the gauge-independent atomic orbital (GIAO) method at the level of density functional theory (DFT). The 6-311+G(d) basis set was used for the inspected fluoride ion. The performance of the effective core potentials (ECP) of LanL2DZ and CRENBL basis sets for metal atoms were compared to 3-21G all-electron basis set. The role of d polarization functions for metal atoms is investigated. The results show that the clusters [FMg3F9](4-), [FM4F6](+) (M = Ca, Sr, Ba), and [FM6](5+) (M = Li, Na, K, Rb, Cs) used to model the bulk solids are reasonable The electrons in the next outermost shell of metal atoms have significant influence on the F-19 NMR calculations and should be treated as valence electrons together with the electrons in the outermost shelf, while die remaining electrons can be represented by the ECP of CRENBL basis set. When the CRENBL basis set (with ECP for core electrons) supplemented with two sets of d polarization functions was used for the metal atoms, the approach of locally dense basis sets can be used to successfully reproduce the F-19 shielding values. Since only the inspected resonant fluorine atom needs a high-grade all-electron basis set, it is a relatively inexpensive means of obtaining reliable shielding properties for the inspected species. In addition, the different exchange-correlation functional implemented in hybrid DFT method has a minor influence on the calculated shielding. Although all the calculated results are somewhat overestimated, the correlation coefficients and the slopes of the fitting lines between the theoretical predictions and experimental observations are close to unity, indicating the good agreement of the theoretical results to the experimental values.
语种	英语
内容类型	期刊论文
源URL	[http://dspace.xmu.edu.cn/handle/2288/70103]
专题	物理技术－已发表论文
推荐引用方式 GB/T 7714	Cai, S. H.,Chen, Z.,Wan, H. L.,et al. Theoretical investigation of F-19 NMR chemical shielding of alkaline-earth-metal and alkali-metal fluorides[J]. http://dx.doi.org/10.1021/jp013503f,2002.
APA	Cai, S. H.,Chen, Z.,Wan, H. L.,&陈忠.(2002).Theoretical investigation of F-19 NMR chemical shielding of alkaline-earth-metal and alkali-metal fluorides.http://dx.doi.org/10.1021/jp013503f.
MLA	Cai, S. H.,et al."Theoretical investigation of F-19 NMR chemical shielding of alkaline-earth-metal and alkali-metal fluorides".http://dx.doi.org/10.1021/jp013503f (2002).