Jenkins Brandon W, Fronczek Frank R, Watkins Steven F
Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803-1804, USA.
Acta Crystallogr Sect E Struct Rep Online. 2012 Aug 1;68(Pt 8):o2538. doi: 10.1107/S1600536812032540. Epub 2012 Jul 25.
The previously reported room-temperature crystal structure [Jaud Baldy, Negrel, Poite & Chanon (1993 ▶). Z. Kristallogr.204, 289-291] of the title compound, C(20)H(8)Cl(12), is monoclinic with Z' = 1, whereas the 90 K structure reported herein is triclinic with Z' = 2 and shows a 2% volume contraction. The crystallographically independent unit chosen consists of both enanti-omers (Λ and Δ) of this propeller-like mol-ecule. Both enanti-omers display quasi-twofold symmetry, with average bond-length/bond-angle deviations of 0.0018 (4) Å and 0.41 (2)° for Λ, and 0.0026 (4) Å and 0.50 (2)° for Δ.
先前报道的标题化合物C(20)H(8)Cl(12)的室温晶体结构[雅德·鲍迪、内格雷尔、普瓦特和沙农（1993▶）。《晶体学报》204, 289 - 291]为单斜晶系，Z' = 1，而本文报道的90K结构为三斜晶系，Z' = 2，且体积收缩2%。所选择的晶体学独立单元由这种螺旋桨状分子的两种对映体（Λ和Δ）组成。两种对映体均显示准二重对称性，Λ的平均键长/键角偏差为0.0018(4) Å和0.41(2)°，Δ的平均键长/键角偏差为0.0026(4) Å和0.50(2)°。
