Synthesis and crystal structures of (2 E)-1,4-bis-(4-chloro-phen-yl)but-2-ene-1,4-dione and (2 E)-1,4-bis-(4-bromo-phen-yl)but-2-ene-1,4-dione

Dominika N Lastovickova; John J La Scala; Rosario C Sausa

doi:10.1107/S205698901800230X

Synthesis and crystal structures of (2 E)-1,4-bis-(4-chloro-phen-yl)but-2-ene-1,4-dione and (2 E)-1,4-bis-(4-bromo-phen-yl)but-2-ene-1,4-dione

Acta Crystallogr E Crystallogr Commun. 2018 Feb 13;74(Pt 3):352-356. doi: 10.1107/S205698901800230X. eCollection 2018 Mar 1.

Authors

Dominika N Lastovickova¹, John J La Scala¹, Rosario C Sausa²

Affiliations

¹ US Army Research Laboratory, RDRL-WMM-G, Aberdeen Proving Ground, MD 21005, USA.
² US Army Research Laboratory, RDRL-WMM-B, Aberdeen Proving Ground, MD 21005, USA.

Abstract

The mol-ecular structure of (2E)-1,4-bis-(4-chloro-phen-yl)but-2-ene-1,4-dione [C₁₆H₁₀Cl₂O₂, (1)] is composed of two p-chlorophenyl rings, each bonded on opposite ends to a near planar 1,4-trans enedione moiety [-C(=O)-CH=CH-(C=O)-] [r.m.s. deviation = 0.003 (1) Å]. (2E)-1,4-Bis(4-bromo-phen-yl)but-2-ene-1,4-dione [C₁₆H₁₀Br₂O₂, (2)] has a similar structure to (1), but with two p-bromophenyl rings and a less planar enedione group [r.m.s. deviation = 0.011 (1) Å]. Both mol-ecules sit on a center of inversion, thus Z' = 0.5. The dihedral angles between the ring and the enedione group are 16.61 (8) and 15.58 (11)° for (1) and (2), respectively. In the crystal, mol-ecules of (1) exhibit C-Cl⋯Cl type I inter-actions, whereas mol-ecules of (2) present C-Br⋯Br type II inter-actions. van der Waals-type inter-actions contribute to the packing of both mol-ecules, and the packing reveals face-to-face ring stacking with similar inter-planar distances of approximately 3.53 Å.

Keywords: 1,4-enedione moiety; NMR; bis-halo-enedione; crystal structure; synthesis.

Grants and funding

This work was funded by Army Research Laboratory grant . Oak Ridge Institute for Science and Education grant . U.S. Department of Energy grant .