Binary and ternary charge-transfer complexes using 1,3,5-trinitrobenzene

Abstract

Three binary and one ternary charge-transfer complexes have been made using 1,3,5-trinitrobenzene, viz. 1,3,5-trinitrobenzene–2-acetylnaphthalene (1/1), C6H3N3O6·C12H10O, (I), 1,3,5-trinitrobenzene–9-bromoanthracene (1/1), C14H9Br·C6H3N3O6, (II), 1,3,5-trinitrobenzene–methyl red (1/1), C15H15N3O2·C6H3N3O6, (III) (systematic name for methyl red: 2-{(E)-[4-(dimethylamino)phenyl]diazenyl}benzoic acid), and 1,3,5-trinitrobenzene–1-naphthoic acid–2-amino-5-nitropyridine (1/1/1), C6H3N3O6·C11H8O2·C5H5N3O2, (IV). All charge-transfer complexes show alternating donor and acceptor stacks, which have weak C—H...O hydrogen bonds perpendicular to the stacking axis. In addition, complex (IV) is a crystal engineering attempt to modify the packing of the stacks by inserting a third molecule into the structure. This third molecule is stabilized by strong hydrogen bonds between the carboxylic acid group of the donor molecule and the pyridine acceptor molecule.