Crystal structure of a tetrakis-substituted pyrazine compound: 2,3,5,6-tetrakis(bromomethyl)pyrazine

Abstract

The title compound, C8H8Br4N2, crystallizes in the enantiomorphic-defining space group P41212 and has a refined Flack x parameter of 0.04 (4). In the asymmetric unit, there are two half-molecules; the whole molecules (A and B) are generated by twofold rotation symmetry. In molecule A, the twofold axis is normal to the pyrazine ring passing through the centre of the ring, while in molecule B, the twofold rotation axis lies in the plane of the pyrazine ring bisecting the C—C aromatic bonds. The two molecules are pseudo-mirror images of one another, and the best fit of the two molecules was obtained for inverted molecule B on molecule A, with an r.m.s. deviation of 0.1048 Å and a maximum deviation of any two equivalent atoms of 0.2246 Å. In the crystal, the A molecules are linked by weak C—H...Br hydrogen bonds and Br...Br interactions [3.524 (3) Å], forming a three-dimensional framework. The B molecules are also linked by weak C—H...Br hydrogen bonds and Br...Br interactions [3.548 (3) Å], forming a three-dimensional network that interpenetrates the network of A molecules.

Keywords

• crystal structure
• tetrakis-substituted
• pyrazine
• chiral