The V-shaped polar molecules encapsulated into Cs (10528)-C72: stability and nonlinear optical response.
Recently, a new sulfide cluster fullerene, Sc2S@Cs (10528)-C72 containing two pairs of fused pentagons has been isolated and characterized (Chen et al., J. Am. Chem. Soc., 2012, 134, 7851). Inspired by this investigation, we propose a question: what properties will be influenced by the interaction between the encapsulated V-shaped polar molecule and C72? To answer this question, four encapsulated metallic fullerenes (EMFs) M2N@C72 (M = Sc or Y, N = S or O) along with pristine Cs-C72 (10528) were investigated by quantum chemistry methods. The results show that the Egap (3.01-3.14 eV) of M2N@C72 are significantly greater than that of pristine Cs-C72 (10528) (2.34 eV). This indicates that the stabilities of these EMFs increase by encapsulating the V-shaped polar molecule into the fullerene. Furthermore, the natural bond orbital (NBO) charge analysis indicates electron transfer from M2N to C72 cage, which plays a crucial role in enhancing first hyperpolarizability (βtot). The βtot follows the order of 1174 au (Y2O@C72) ≈ 1179 au (Sc2O@C72) > 886 au (Y2S@C72) ≈ 864 au (Sc2S@C72) > 355 au (C72). This indicates that the βtot of M2N@C72 is more remarkable than that of pristine Cs-C72 (10528) due to the induction effect of the encapsulated molecule. Compared with sulfide cluster fullerenes (Y2S@C72 and Sc2S@C72), oxide cluster fullerenes (Sc2O@C72 and Y2O@C72) show much larger βtot due to the small ionic radius and the large electronegativity of oxygen. In contrast, the metal element (scandium and yttrium) has a slight influence on the βtot. Thus, oxide cluster fullerenes are candidates to become promising nonlinear optical materials with higher performance.
Institute of Functional Materials Chemistry, Faculty of Chemistry Northeast Normal University, Changchun 130024, Jilin, P. R. China. hlxu@nenu.edu.cn zmsu@nenu.edu.cn.
Li-Jie
LJ
Wang
Rong-Lin
RL
Zhong
Shi-Ling
SL
Sun
Hong-Liang
HL
Xu
Xiu-Mei
XM
Pan
Zhong-Min
ZM
Su
D037741:Fullerenes / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D055620:Optical Phenomena; D009942:Organometallic Compounds / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry; D011789:Quantum Theory; D012538:Scandium / Q000737:chemistry*; D013440:Sulfides / Q000737:chemistry; D015019:Yttrium / Q000737:chemistry*
D037741:Fullerenes; D009942:Organometallic Compounds; D013440:Sulfides; D015019:Yttrium; D010100:Oxygen; D012538:Scandium