Department of Chemistry, University of California, One Shields Avenue, Davis, California 95616, USA.
J Am Chem Soc. 2011 May 4;133(17):6752-60. doi: 10.1021/ja200289w. Epub 2011 Apr 7.
Single-crystal X-ray diffraction studies of Sc(2)(μ(2)-S)@C(s)(6)-C(82)·Ni(II)(OEP)·2C(6)H(6) and Sc(2)(μ(2)-S)@C(3v)(8)-C(82)·Ni(II)(OEP)·2C(6)H(6) reveal that both contain fully ordered fullerene cages. The crystallographic data for Sc(2)(μ(2)-S)@C(s)(6)-C(82)·Ni(II)(OEP)·2C(6)H(6) show two remarkable features: the presence of two slightly different cage sites and a fully ordered molecule Sc(2)(μ(2)-S)@C(s)(6)-C(82) in one of these sites. The Sc-S-Sc angles in Sc(2)(μ(2)-S)@C(s)(6)-C(82) (113.84(3)°) and Sc(2)(μ(2)-S)@C(3v)(8)-C(82) differ (97.34(13)°). This is the first case where the nature and structure of the fullerene cage isomer exerts a demonstrable effect on the geometry of the cluster contained within. Computational studies have shown that, among the nine isomers that follow the isolated pentagon rule for C(82), the cage stability changes markedly between 0 and 250 K, but the C(s)(6)-C(82) cage is preferred at temperatures ≥250 °C when using the energies obtained with the free encapsulated model (FEM). However, the C(3v)(8)-C(82) cage is preferred at temperatures ≥250 °C using the energies obtained by rigid rotor-harmonic oscillator (RRHO) approximation. These results corroborate the fact that both cages are observed and likely to trap the Sc(2)(μ(2)-S) cluster, whereas earlier FEM and RRHO calculations predicted only the C(s)(6)-C(82) cage is likely to trap the Sc(2)(μ(2)-O) cluster. We also compare the recently published electrochemistry of the sulfide-containing Sc(2)(μ(2)-S)@C(s)(6)-C(82) to that of corresponding oxide-containing Sc(2)(μ(2)-O)@C(s)(6)-C(82).
通过对 Sc(2)(μ(2)-S)@C(s)(6)-C(82)·Ni(II)(OEP)·2C(6)H(6) 和 Sc(2)(μ(2)-S)@C(3v)(8)-C(82)·Ni(II)(OEP)·2C(6)H(6) 的单晶 X 射线衍射研究表明，这两种物质都包含完全有序的富勒烯笼。Sc(2)(μ(2)-S)@C(s)(6)-C(82)·Ni(II)(OEP)·2C(6)H(6) 的晶体学数据显示了两个显著的特征：存在两个略有不同的笼状位置和一个完全有序的分子 Sc(2)(μ(2)-S)@C(s)(6)-C(82) 在其中一个位置。Sc(2)(μ(2)-S)@C(s)(6)-C(82) 中的 Sc-S-Sc 角度（113.84(3)°）和 Sc(2)(μ(2)-S)@C(3v)(8)-C(82) 不同（97.34(13)°）。这是首例富勒烯笼状异构体的性质和结构对包含在其中的团簇的几何形状产生明显影响的情况。计算研究表明，在遵循孤立五边形规则的 C(82) 的九个异构体中，笼状稳定性在 0 到 250 K 之间发生显著变化，但在使用自由封装模型 (FEM) 获得的能量时，C(s)(6)-C(82) 笼在温度≥250°C 时更受欢迎。然而，在使用刚性转子-谐振子 (RRHO) 近似获得的能量时，C(3v)(8)-C(82) 笼在温度≥250°C 时更受欢迎。这些结果证实了这样一个事实，即两种笼都被观察到并可能捕获 Sc(2)(μ(2)-S) 团簇，而早期的 FEM 和 RRHO 计算仅预测 C(s)(6)-C(82) 笼更有可能捕获 Sc(2)(μ(2)-O) 团簇。我们还将含有硫化物的 Sc(2)(μ(2)-S)@C(s)(6)-C(82) 的最近发表的电化学与相应的含有氧化物的 Sc(2)(μ(2)-O)@C(s)(6)-C(82) 进行了比较。
