Polymorphism and Crystal Structure of Chiral Smectogenic 4′-Heptyloxy-4-biphenylyl<i>p</i>-[(<i>S</i>)-2-Methylbutyl]benzoate
作者:Kayako Hori、Yuji Ohashi
DOI:10.1246/bcsj.62.3216
日期:1989.10
Two crystal forms 1 and 2 were found for the title compound. DSC measurements showed that the two crystals transform to different mesophases (Sm* I and Sm* J). Crystal data. 4′-Heptyloxy-4-biphenylyl p-[(S)-2-methylbutyl]benzoate, 1, Mr=458.61, C31H38O3, monoclinic, P21, T=298 K, a=15.065(3), b=45.59(2), c=5.636(1) Å, β=95.51(2)°, V=4109(2) Å3, Z=6, dx=1.118 Mg m−3, μ=0.475 mm−1, F(000)=1488; 2, triclinic, P1, a=13.37(2), b=22.96(2), c=10.213(5) Å, α=105.55(5), β=105.22(6), γ=102.31(9)°, V=2775(5) Å3, Z=4, dx=1.102 M gm−3. The crystal structure of 1 has been determined by single crystal X-ray analysis. Final R was 0.109. The crystal has a distinct layer structure similar to that of a smectic liquid crystal. Two of the three crystallographically independent molecules with extended paraffin chains have parallel arrangement, to which the third molecule with a twisted and highly disordered chain is antiparallel. The paraffin chains of the parallel molecules in a layer have close contacts with each other. Such contacts would enhance the intra-layer interaction which causes the transition to Sm* I.
标题化合物有两种晶体结构,分别为1和2。DSC测量显示,这两种晶体会转变为不同的中间相(Sm* I和Sm* J)。晶体数据。4′-庚氧基-4-联苯基对[(S)-2-甲基丁基]苯甲酸酯,1,Mr=458.61,C31H38O3,单斜晶系,P21,T=298 K,a=15.065(3),b=45.59(2),c=5.636(1) Å,β=95.51(2)°,V=4109(2) Å3,Z=6,dx=1.118 Mg m−3,μ=0.475 mm−1,F(000)=1488;2,三斜晶系,P1,a=13.37(2),b=22.96(2),c=10.213(5) Å,α=105.55(5),β=105.22(6),γ=102.31(9)°,V=2775(5) Å3,Z=4,dx=1.102 M gm−3。1的