organic compounds
Open access
In the title methylene-bridged di(tetrahydropyrimidinium) salt, C33H50N42+·2Br−·C2H5OH·H2O, the two tetrahydropyrimidinium rings have envelope conformations with the central CH2 C atom as the flap. Their mean planes are inclined to one another by 73.31 (13)° and the attached benzene rings are inclined to one another by 67.39 (15)°. The methylene-C—N bond lengths in the tetrahydropyrimidinium rings are 1.314 (3) and 1.304 (3) Å, values typical for C=N double bonds. The distances between the methylene-bridge C atom and the linked tetrahydropyrimidinium N atom are 1.457 (3) and 1.465 (3) Å, values typical for C—N single bonds. The molecules co-crystallized with H2O and EtOH molecules from the solvent. In the crystal, there is a zigzag chain along [010] of water molecules linked by one of the Br− anions via O—HBr hydrogen bonds. The second Br− anion is hydrogen bonded (O—HBr) to the ethanol solvent molecule. There are also a number of C—HBr and C—HO hydrogen bonds present, leading to the formation of a two-dimensional network lying parallel to the bc plane.