软X-射线分光晶体马来酸氢十八酯的晶体结构

测定了标题化合物C_(22)H_(40)O_4的晶体结构，属空间群Pī，a=0.6833(2)，b=3.1662(5)，c=0.5392(1) nm，α＝90.63(2)．β=102.61(2)，γ＝89.03(2)°，Z=2偏离因子R=0.0465，晶体中分子通过氢键形成二聚体，二聚体在晶体中排列成层，进而这些层堆垛成晶体结构，层内二聚体之间相互作用比层之间的相互作用强．分子中的十八烷基的碳原子基本共面．其碳链呈锯齿状伸展，初步解释了晶体生长过程中的一些现象．

Crystal Structure of Soft X-Ray Analyzer Crystal——Octadecyl Hydrogen Maleate(OHM,C22H40O4)

The crystal structure of octadecyl hydrogen maleate was determined by Xray diffeaction method. C_(22)H_(40)O_4, Mr=368.56, triclinic, space group Pī, a=0.6833 (2), b=3.1662 (5), c=0.5392 (1) nm, α=90.63 (2), β=102.61 (2), γ=89.03 (2)°, V=1.1383 (5) nm. Z=2, Dc.=1.08 g·cm~(-3), F(000)=408, λ(Mo K_α) =0.071069 nm, μ(Mo K_α)=0.67 cm~(-1), final R=0.0465 for 1332 observations with I ≥3σ(I) and 240 variables. In the crystal OHM molecules form dimers via intermolecular hydrogen bonding between carboxyl groups. The long hydrocarbon chain of octadecyl is zigzag-like and the carbon atoms of this chain are basically coplanar. These dimers arrange along (101) plane to form a layer, then these layers stack along 010] to give the crystal structure. The van der Waals interaction intralayer is evidently larger than interlayer. On the base of the crystal structure some phenomena in the crystal growth of OHM were illustrated.