Crystal structure and characterization of l-arginine chlorate and l-arginine bromate

The salts l-arginine.HClO3 and l-arginine.HBrO3, were synthesized. The crystals obtained were characterized by IR and NQR spectroscopy, thermal analysis, Nd:YAG laser radiation second harmonic generation, dielectric, piezoelectric and pyroelectric measurements and their crystal structures were determined. l-arginine.HClO3 and l-arginine.HBrO3 are crystallized in orthorhombic (space group P212121) and triclinic (space group P1) systems, respectively. Their structures consist of the protonated arginine cation [+(H2N)2CNH(CH2)3CH(NH3+)COO−] and respective ClO3− or BrO3− anions. Hydrogen bonds (stronger in the bromate) connect anions with cations and the latter with each other. However, these salts have essential distinctions in crystal packing.