title: A new polymorph of 1,4-dibromo-2,5-dimethylbenzene: H···Br and Br···π versus Br···Br interactions.
abstract: A new polymorph, (Ib), of the title compound, C(8)H(8)Br(2), crystallizes in the space group P2(1)/n, the same as the known polymorph (Ia) but with Z = 2 (imposed inversion symmetry) rather than Z = 4. The molecular structures are closely similar because the molecule has no degrees of torsional freedom except for methyl groups, but the packing arrangements are completely different. Polymorph (Ia) is characterized by linked trapezia of Br···Br interactions, whereas polymorph (Ib) features H···Br and Br···π interactions.
authors.affiliation: Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Postfach 3329, 38023 Braunschweig, Germany. p.jones@tu-bs.de
authors.forename: Peter G
authors.initials: PG
authors.lastname: Jones
authors.forename: Piotr
authors.initials: P
authors.lastname: Kuś