Research Information System
ACTA CRYSTALLOGRAPHICA SECTION E-CRYSTALLOGRAPHIC COMMUNICATIONS, pp.120-134, 2025 (ESCI)
The asymmetric units of the compounds, C8H5BrCl2O (I), and C9H8Br2O (II), contain two and one crystallographically independent molecules, respectively. In compound (I), the planar rings are oriented at a dihedral angle of 13.23 (8)degrees. In crystals of both compounds, intermolecular C-H center dot center dot center dot O hydrogen bonds link the molecules into infinite chains along the b-axis direction. In crystal of (I), there are pi-pi interactions between the centroids of the parallel rings with centroid-tocentroid distances of 3.5974 (14), 3.6178 (16) and 3.9387 (16) angstrom while neither pi-pi nor C-H center dot center dot center dot pi(ring) interactions are present in (II). The Hirshfeld surface analyses of the crystal structures indicate that the most important contributions for the crystal packings are from H center dot center dot center dot Cl/Cl center dot center dot center dot H (27.5%), H center dot center dot center dot O/O center dot center dot center dot H (15.0%), H center dot center dot center dot Br/Br center dot center dot center dot H (10.2%) and H center dot center dot center dot H (9.0%) for (I) and H center dot center dot center dot Br/Br center dot center dot center dot H (36.1%), H center dot center dot center dot H (22.2%), H center dot center dot center dot O/O center dot center dot center dot H (14.1%) and H center dot center dot center dot C/C center dot center dot center dot H (13.9%) for (II). Hydrogen bonding and van der Waals interactions are the dominant interactions in the crystal packings. The volumes of the crystal voids and the percentages of free spaces in the unit cells were calculated to 111.55 angstrom(3) and 12.27% for (I) and 63.37 angstrom and 6.69% for (II), showing that no large cavities are present in either structure.