四（对叔丁基）硫杂杯[4]芳烃选择性包合四氟硼酸分子：晶体结构和理论研究

X－射线晶体衍射测定了4－(对叔丁基)硫杂杯4]芳烃选择性地包合四氟硼酸分子。晶体学数据为：C₄₀H₄₉O₄S₄BF₄，M_r=808.88， 四方锥， 空间群 P4/nmm，a=1.5887(2), b=1.5887(2), c=0.8428(0) nm, V=2.127(2) nm³, Z=2, D_c=1.263 g·cm^-3, R₁=0.0405, _WRI>2σ(I)]=0.1218. ¹⁹F NMR谱中，在-151.4 ppm处出现的峰，证实了四氟硼酸的存在。用Bader的分子中的原子理论方法计算了分子结构中的非共价键相互作用。结果显示，在四氟硼酸包合物中，除了F…H－C氢键作用和阳离子－阴离子的静电作用外，F^δ--C^δ+静电作用的存在也对4－(对叔丁基)硫杂杯4]芳烃憎水空腔包合氟硼酸分子起到了稳定作用。

Selective Inclusion of Fluoboric Acid by Tetra(p‐tert‐butyl)‐thiacalix[4]arene: Crystal Structure and Theoretical Study

The structure of fluoboric acid selectively embedded within the hydrophobic cavity of the tetra(p‐tert‐butyl)thiacalix4]arene was determined by X‐ray crystallography. Crystal data: C₄₀H₄₉O₄S₄BF₄, M_r=808.88, tetragonal, space group P4/nmm, a=1.5887(2) nm, b=1.5887(2) nm, c=0.8428(0) nm, V=2.127(2) nm³, Z=2, D_c=1.263 g·cm^?3, R₁=0.0405, wRI>2σ(I)]=0.1218. ¹⁹F NMR confirmed the existence of fluoboric acid with a signal at δ ?151.4. The noncovalent interactions in the molecular structure were characterized by Bader's theory of “atoms in molecules” (AIM). The results reveal that besides the C–H–F hydrogen bonding and cation‐anion electrostatic interaction present in the fluoboric acid inclusion complex, the F^δ?‐C^δ+ electrostatic interaction also exists for stabilizing the fluoboric acid embedded within the hydrophobic cavity of tetra(p‐tert‐butyl)thiacalix4]arene.