Acta Chimica Sinica ›› 2014, Vol. 72 ›› Issue (10): 1105-1109.DOI: 10.6023/A14060448 Previous Articles     Next Articles



雷丹, 赵冲, 甘利华   

  1. 西南大学化学化工学院 重庆 400715
  • 投稿日期:2014-06-09 修回日期:2014-08-25 发布日期:2014-08-25
  • 通讯作者: 甘利华
  • 基金资助:

    项目受国家自然科学基金(No. 51272216)和中央高校基金(No. XDJK2014B032)资助.

Structures and Properties of Metal Sulfide Fullerene Sc2S@C90

Lei Dan, Zhao Chong, Gan Lihua   

  1. School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715
  • Received:2014-06-09 Revised:2014-08-25 Published:2014-08-25
  • Supported by:

    Project supported by the National Natural Science Foundation of China (No. 51272216) and the Fundamental Research Funds for the Central Universities of China (No. XDJK2014B032).

Metallic sulfide fullerene Sc2S@C90 has been detected by mass spectra but not been isolated and structurally characterized. It is impossible to perform extensive tests on Sc2S@C90 due to its low yield, quantum chemical calculations thus become an important method to predict or identify its structure and properties. Here a systematic density functional theory study are first performed on 15756 isomers of fullerene C90 and their anions with 0~3 pairs of fused-pentagons, then 30 isomers of metallic sulfide fullerenes Sc2S@C90 are constructed by putting Sc2S into the selected candidate cages with different orientations and geometrical optimizations are performed on these isomers with the density functional theory method. The calculated results demonstrate that the two lowest-energy isomers are Sc2S@C90:99913 and Sc2S@C90:99915, respectively. Both isomers satisfy the isolated-pentagon rule. To clarify the relative stabilities of the five lowest-energy isomers of Sc2S@C90 at high temperatures, enthalpy-entropy interplay has been taken into consideration with respect to the temperature range of up to 4000 K; the calculations demonstrate that the two lowest-energy isomers of Sc2S@C90 may coexist in the soot at high temperatures. Structural analysis demonstrated that the two isomers can transfer into each other by two Stone-Wales rotations, further suggesting the possibility of interconversion between them. Molecular orbital analysis indicates that Sc2S cluster transfers four electrons to the cage; however nature charge analysis demonstrates the charges transferred from the encaged cluster to the parent cage is much smaller than that with the simple molecular orbital analysis. The quantum theory of atoms in molecules is used to investigate the connectivity and interaction nature between the encaged cluster and parent cage. The results show that there are strong interactions between the encaged cluster and parent cage. The simulated infrared spectra of the two lowest-energy isomers are provided to assist future experimental identification and characterization of the structure of Sc2S@C90.

Key words: endohedral fullerene, Sc2S@C90, density functional theory, relative concentrations, QTAIM