Zhao Sha-Sha, Su Qiong, Peng Zhi-Hong, An De-Lie
Department of Chemistry, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, People's Republic of China.
Acta Crystallogr Sect E Struct Rep Online. 2014 Jan 15;70(Pt 2):o137. doi: 10.1107/S1600536814000397. eCollection 2014 Feb 1.
The title mol-ecule, C18H16O2S2, reveals crystallographic twofold rotation symmetry (with both S atoms lying on the axis) and one half-mol-ecule defines an asymmetric unit. The dithiine ring is in a boat conformation. The aromatic ring and the C=C bond are nearly coplanar, with small torsion angles of -171.26 (19) and 8.5 (3)°. The two S-C bond lengths [1.7391 (19) and 1.7795 (18) Å] are shorter than single C-S bonds and longer than analogous C=S double bonds, which indicates a certain degree of conjugation between the lone pair on the S atom and π electrons of the C=C bond. The crystal packing only features van der Waals inter-actions.
标题分子C18H16O2S2具有晶体学二重旋转对称性(两个S原子均位于轴上),一个半分子构成一个不对称单元。二硫环呈船式构象。芳环和C=C键近乎共面,扭转角分别为 -171.26 (19)°和8.5 (3)°。两条S-C键长[1.7391 (19) 和1.7795 (18) Å] 比单键C-S键短,比类似的C=S双键长,这表明S原子上的孤对电子与C=C键的π电子之间存在一定程度的共轭。晶体堆积仅存在范德华相互作用。