Molecular complexes of alprazolam with carboxylic acids, boric acid, boronic acids, and phenols. Evaluation of supramolecular heterosynthons mediated by a triazole ring.
A series of molecular complexes, both co-crystals and salts, of a triazole drug-alprazolam-with carboxylic acids, boric acid, boronic acids, and phenols have been analyzed with respect to heterosynthons present in the crystal structures. In all cases, the triazole ring behaves as an efficient hydrogen bond acceptor with the acidic coformers. The hydrogen bond patterns exhibited with aromatic carboxylic acids were found to depend on the nature and position of the substituents. Being a strong acid, 2,6-dihydroxybenzoic acid forms a salt with alprazolam. With aliphatic dicarboxylic acids alprazolam forms hydrates and the water molecules play a central role in synthon formation and crystal packing. The triazole ring makes two distinct heterosynthons in the molecular complex with boric acid. Boronic acids and phenols form consistent hydrogen bond patterns, and these are seemingly independent of the substitutional effects. Boronic acids form noncentrosymmetric cyclic synthons, while phenols form O--H...N hydrogen bonds with the triazole ring.
Varughese
Sunil
S
Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560 012, India.
Azim
Yasser
Y
Desiraju
Gautam R
GR
D000525:Alprazolam / Q000737:chemistry*; D014151:Anti-Anxiety Agents / Q000737:chemistry*; D001888:Boric Acids / Q000737:chemistry*; D001897:Boronic Acids / Q000737:chemistry*; D002264:Carboxylic Acids / Q000737:chemistry*; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D010636:Phenols / Q000737:chemistry*; D014230:Triazoles / Q000737:chemistry
D014151:Anti-Anxiety Agents; D001888:Boric Acids; D001897:Boronic Acids; D002264:Carboxylic Acids; D010636:Phenols; D014230:Triazoles; C032688:boric acid; D000525:Alprazolam