MOLECULAR COCRYSTALS OF CARBOXYLIC-ACIDS .14. THE CRYSTAL-STRUCTURES OF THE ADDUCTS OF PYRAZINE-2,3-DICARBOXYLIC ACID WITH 4-AMINOBENZOIC ACID, 3-HYDROXYPYRIDINE AND 3-AMINO-1,2,4-TRIAZOLE

The 1:1 molecular adducts of pyrazine-2,3-dicarboxylic acid with 4-ami nobenzoic acid, [(C6H3N2O4)- (C7H8NO2)+], 3-hydroxypyridine, [(C6H4N2O 4)(C5H5NO)], and 3-amino-1,2,4-triazole, [(C6H3N2O)4)- (C2H5N4)+] have been prepared, and their structures determined by X-ray diffraction m ethods. All structures involve intra- and inter-molecular hydrogen-bon ding interactions. The 1:2 complex of pyrazine-2,3-dicarboxylic acid w ith triphenylphosphine oxide has also been prepared, and characterized by using spectroscopic methods.