A Comparative Study of (tBu3Si)SiX2SiX2(SitBu3) (X = Cl, Br, I) Including the Result of the X-Ray Structure Analysis of (tBu3Si)SiI2SiI2(SitBu3)
作者:Michael Bolte、Hans-Wolfram Lerner
DOI:10.1007/s10870-010-9851-2
日期:2011.2
The tetraiodotetrasilane (tBu3Si)SiI2SiI2(SitBu3) can be prepared from precursor (tBu3Si)SiH2SiH2(SitBu3). When (tBu3Si)SiH2SiH2(SitBu3) was treated with an excess of iodine at 120 °C, (tBu3Si)SiI2SiI2(SitBu3) was formed. X-ray quality crystals of (tBu3Si)SiI2SiI2(SitBu3) were grown from benzene at ambient temperature. The tetraiodotetrasilane (tBu3Si)SiI2SiI2(SitBu3) crystallizes in the monoclinic space group C2/c, a = 10.0110(10) Å, b = 13.9130(10) Å, c = 25.422(2) Å, β = 99.072(4)°, V = 3496.6(5) Å3, Z = 4, d calcd = 1.829 g cm3; R 1 = 0.0844, wR 2 = 0.1854 for 3,017 reflections with I > 2σ(I). X-ray-crystallographic data show that the bromo and iodo derivatives (tBu3Si)SiX2SiX2(SitBu3) (X = Br, I) are isomorphous. The solid-state structure of (tBu3Si)SiI2SiI2(SitBu3) as well as those of (tBu3Si)SiX2SiX2(SitBu3) (X = Cl, Br) reveals a staggered conformation which adopts a trans-orientation of the supersilyl substituent. Unequal dihedral angles as found in (tBu3Si)SiX2SiX2(SitBu3) (X = Cl, Br, I) indicate that these compounds are sterically overcrowded. In the solid-state (tBu3Si)SiI2SiI2(SitBu3) features a staggered conformation which adopts a trans-orientation of the supersilyl group. However the solid-state structure of (tBu3Si)SiI2SiI2(SitBu3) reveals unequal dihedral angles.
四碘四硅烷 (tBu3Si)SiI2SiI2(SitBu3) 可由前驱体 (tBu3Si)SiH2SiH2(SitBu3) 制备而成。在 120 ℃ 下用过量碘处理 (tBu3Si)SiH2SiH2(SitBu3) 时,会生成 (tBu3Si)SiI2SiI2(SitBu3)。(tBu3Si)SiI2SiI2(SitBu3)的 X 射线质量晶体是在环境温度下从苯中生长出来的。四碘四硅烷 (tBu3Si)SiI2SiI2(SitBu3) 在单斜空间群 C2/c 中结晶,a = 10。0110(10) Å, b = 13.9130(10) Å, c = 25.422(2) Å, β = 99.072(4)°, V = 3496.6(5) Å3, Z = 4, d calcd = 1.829 g cm3; R 1 = 0.0844, wR 2 = 0.1854 for 3,017 reflections with I > 2σ(I).X 射线晶体学数据表明,溴和碘衍生物 (tBu3Si)SiX2SiX2(SitBu3) (X = Br, I) 是同构的。(tBu3Si)SiI2SiI2(SitBu3)和(tBu3Si)SiX2SiX2(SitBu3)(X = Cl, Br)的固态结构显示出一种交错构象,超硅取代基采用了反式取向。在(tBu3Si)SiX2SiX2(SitBu3)(X = Cl、Br、I)中发现的不相等的二面角表明这些化合物在立体上过于拥挤。在固态下,(tBu3Si)SiI2SiI2(SitBu3)具有交错构象,超硅基团呈反式取向。然而,(tBu3Si)SiI2SiI2(SitBu3)的固态结构显示出不等的二面角。