Enforcing Molecule’s pi-Conjugation and Consequent Formation of the Acid-Acid Homosynthon over the Acid-Pyridine Heterosynthon in 2-Anilinonicotinic Acids

Sihui Long and Tonglei Li
Crystal Growth & Design, 10:2465-2469, 2010

Abstract (from publisher):¬†Two different synthons, acid-acid and acid-pyridine, are present in the crystal structures of 2-(phenylamino)nicotinic acid. The intermolecular hydrogen-bonding motifs are determined by molecular conformation and conformational energy. By covalently linking electron-withdrawing groups to the phenyl ring, it is possible to strengthen the molecule’s global pi-conjugation and thereby lead to only the acid-acid homosynthon in crystal packing and prohibit the competing acid-pyridine heterosynthon.

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