M. Kubicki, T. W. Kindopp, M. Capparelli
Oct 1, 1994
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0
Influential Citations
2
Citations
Journal
Canadian Journal of Chemistry
Abstract
The crystal structures of three tricyclic quinoxalinedione derivatives, 6-bromo-1,8-ethano-4-hydro-2,3-quinoxalinedione (1), 6-methyl-1,8-ethano-4-hydro-2,3-quinoxalinedione hydrate (2), and 6-styryl-1,8-ethano-4-hydro-2,3-quinoxalinedione (3), are reported. For 1 and 2, the space groups are P21/n with the unit cell parameters for 1: a = 7.4003(5) A, b = 8.5799(5) A, c = 14.3127(9) A, β = 90.639(6)°, and for 2: a = 7.0590(2) A, b = 10.7483(3) A, c = 13.9509(7) A, β = 103.290(3)°. For 3, the space group is P21/c, with a = 19.3683(10) A, b = 8.0962(16) A, c = 19.5801(16) A, β = 114.028(6)°. Compound 3 crystallizes with two molecules in the asymmetric part of the unit cell; in one of them the styryl group is disordered. The geometries of the 1,8-ethano-4-hydro-2,3-quinoxalinedione fragments are similar in all observations, with the differences mainly caused by the different nature of the substituents in the 6-position. Hydrogen bonds connect the molecules into three-dimensional networks. Head-to-tail π-stack...