R^+-SiF_3(R=Li,Na,K)分子构型及稳定性的理论研究(英文)

Theoretical Investigation on the Structures and Stability of the R^+-SiF_3(R=Li,Na,K) Complexes

在B3LYP/6-311+G(2d,2p)理论水平上对R+-SiF3(R=Li,Na,K)各构型进行结构优化,NBO原子电荷分析用NPA程序.用同样的理论水平上对R+-SiF3(R=Li,Na,K)进行零点能、总能、焓、相对能量计算和碱金属离子亲和能计算,计算出能量结合频率分析确定配合物构型的稳定性.优化的几何构型、NBO分析表明R+(R=Li,Na,K)和SiF3形成的是离子偶极型配合物.Li+,Na+,K+形成最稳定分子的亲和能分别是90.46KJ/mol、57.52KJ/mol和37.83KJ/mol.足够大的锂离子亲和能表明锂离子吸附SiF3的配合物能被锂离子吸附质谱仪探测到.

Abstract：The optimized geometrical parameters were obtained at the level B3LYP in conjunction with the 6- 311 ＋ G（2d, 2p） basis set. NBO atomic charges were derived by using the natural population analysis （NPA） scheme. The zero-point energies （ZPE）, total energies （E）, relative energies （△E）, and affinities of ligands（△H）of the optimized structure were calculated by at the same level and basis set. The optimized structures and NBO analysis indicated that the complexes of R ＋ （R = Li, Na, k） and SiF3 behaviours as ion-dipole molecules. The calculated affinity energies of the most stable complexes are 90.46KJ/mol, 57.52KJ/mol, and 37.83KJ/mol respectively. These values suggest that the R＋ -SiF3（R= Li, Na, K） complexes could be observed as stable species in gas phase, which supports Fujii＇s proposal that Li＋ ion attachment mass spectrometry can serve as a conceivable technique to detect and quantify the emissions of the SiF3.