Effect of a halogen bond on the crystal structure of terphenyldicarboxylic acid derivatives.

The syntheses and structures of dimethyl [1,2:2,3-terphenyl]-1,3-dicarboxylate (1), dimethyl 2,2-diiodo[1,2:2,3-terphenyl]-1,3-dicarboxylate (2), potassium [1,2:2,3-terphenyl]-1,3-dicarboxylate (3) and dimethyl [1,1'-biphenyl]-4,4'-dicarboxylate (4) are reported. Neighboring phenyl rings in compounds 1, 3 and 4 have a planar structure (torsion angles are 0.6-4.

Variations of quantum electronic pressure under the external compression in crystals with halogen bonds assembled in Cl-, Br-, I-synthons.

The inner-crystal quantum electronic pressure was estimated for unstrained CCl, CBr, and CI crystals and for those under external compression simulated from 1 to 20 GPa. The changes in its distribution were analyzed for the main structural elements in considered crystals: for triangles of the typical halogen bonds assembled in Hal-synthons, where Hal = Cl, Br, I; for Hal..