5-(4,5-Ethylenedithio-1,3-dithiol-2-ylidene)-1,3,4,6-tetrathiapentalen-2-one (EDTO-TTP) and 5-[4,5-(ethene-1,2-diyldithio)-1,3-dithiol-2-ylidene]-1,3,4,6-tetrathiapentalen-2-one (VDTO-TTP)

Abstract

The title sulfur-rich organic molecular crystals, namely EDTO-TTP (C(9)H(4)OS(8)) and VDTO-TTP (C(9)H(2)OS(8)), are characterized by conjugated C-S bonds and S...S intermolecular short contacts. The planar EDTO-TTP molecules are parallel packed and exhibit strong intermolecular interactions, including side-by-side transverse S...S contacts, face-to-face longitudinal pi-pi interactions and C-H...O hydrogen bonding. On cooling the EDTO-TTP crystal from 220 to 120 K, the cell dimensions and the intermolecular distances (such as S...S contacts and especially pi-pi spacings) become shorter, while the intramolecular bonds become longer. The curved VDTO-TTP molecules are packed in such a way as to make the crystal fully depolarized. The intermolecular interactions of the VDTO-TTP crystal are relatively weak, because of the weak pi-pi interactions and the lack of hydrogen bonding.