八甲基二乙烯三碘化铵高聚碘的合成及其晶体结构

Synthesis and Crystal Structure of a Novel Octamethyldiethylenetriammonium Triiodide Polyiodide

在甲醇中,五甲基二乙烯三胺和碘甲烷经取代反应合成了一个新型的三阳离子季铵盐——八甲基二乙烯三碘化铵(2),并经封管缓慢扩散溶剂法获得其单晶。2在甲醇中与单质碘回流反应合成了一种新型三阳离子季铵盐高聚碘(C12H32N3I12,3),通过缓慢蒸发溶剂结晶法获得其单晶。2和3的结构经IR和X-单晶衍射表征。2含一个结晶乙腈分子,属单斜晶系,空间群P21/m,晶胞参数a=9.025 1(7),b=7.700 4(5),c=17.264 0(13),β=99.681(7)°,V=1 182.71(15)3,Z=2,Dc=1.868 g·cm-3,R int=0.021 3,R1=0.059 1,ωR2=0.177 4。3属三斜晶系,空间群Pī,晶胞参数a=9.811 6(7),b=9.986 5(8),c=20.034 9(16),α=89.158(7)°,β=82.452(6)°,γ=69.953(7)°,V=1 827.2(2)3,Z=2,Dc=3.165 g·cm-3,R int=0.034 8,R1=0.042 6,ωR2=0.098 8。3中季铵根阳离子完全被周围的高聚碘阴离子所包裹,其中I-3与相邻的I-5组成U型的I2-8,而I2与相邻的两个I-3组成Z型的I2-8,两个U型I2-8与一个Z型I2-8交替排列构成了3的离散超分子碘链基本单元。随着相邻离散碘链基本单元排列模式和U型I2-8开口方向的不同,使I2-8离散超分子碘链单元堆积为高聚碘离子的三维结构。

A novel quaternary tri-ammonium salt,octamethyldiethylenetriammonium triiodide（ 2）, was synthesized by substitution reaction of pentamethyl diethylenetriamine with methyl iodide in methanol. The single crystal of 2 was obtained in the mixed solvents of acetonitrile / DMF. The polyiodide（ 3） was synthesized by reaction of 2 with iodine at reflux in methanol and the single crystal of 3 was prepared. The structures were characterized by IR and single crystal X-ray diffraction. 2 contains a crystalline acetonitrile molecule,and belongs to monoclinic system,space group P2 1 / m with a = 9. 025 1（ 7） ,b = 7. 700 4（ 5）,c = 17. 264 0（ 13） ,β = 99. 681（ 7） °,V = 1 182. 71（ 15） 3, Z = 2,Dc = 1. 868 g·cm- 3,R int = 0. 021 3,R 1 = 0. 059 1,ωR2 = 0. 177 4. 3 belongs to triclinic system,space group Pī with a = 9. 811 6（ 7） ,b = 9. 986 5（ 8） ,c = 20. 034 9（ 16） ,α = 89. 158（ 7） °,β = 82. 452（ 6） °,γ = 69. 953（ 7） °,V = 1 827. 2（ 2） 3,Z = 2,Dc = 3. 165 g·cm- 3,R int = 0. 034 8,R 1 = 0. 042 6,ωR 2 = 0. 098 8. The quaternary ammonium cation in 3 was completely wrapped by polyiodide anions,among them I-3 and the adjacent I-5 constitute the U-shaped I2-8,while I 2 and the adjacent I-3 constitute the Z-shaped I2-8,two U-shaped I2-8 and one Z-shaped I2-8 arrange alternately and form a discrete basic unit of supramolecular iodine chains of 3. With the different arrange modes of adjacent discrete basic unit and the direction of opening of U-shaped I2-8, the discrete units of supramolecular iodine chains make the polyiodide pack the three-dimensional structure.