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

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), C 6 H 3 N 3 O 6 ·C 12 H 10 O, (I), 1,3,5-trinitrobenzene–9-bromoanthracene (1/1), C 14 H 9 Br·C 6 H 3 N 3 O 6 , (II), 1,3,5-trinitrobenzene–methyl red (1/1), C 15 H 15 N 3 O 2 ·C 6 H 3 N 3 O 6 , (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), C 6 H 3 N 3 O 6 ·C 11 H 8 O 2 ·C 5 H 5 N 3 O 2 , (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.