Reinvestigation of the Crystal Growth of “L-Proline Succinate” and “L-Threonine Zinc Acetate” Showing Use of Infrared Spectra for Product Identification

Reinvestigation of the growth of L-proline succinate (1) (Paramasivam and Ramachandra Raja, Journal of Crystallization Process and Technology, 2 (2012) 21 - 24; Balamurugaraj et al., Journal of Material Physics and Chemistry 1 (2013) 4 - 8) and L-threonine zinc acetate (2) (Puhal Raj and Ramachandra Raja, Photonics and Optoelectronics, 2 (2013) 56 - 64) is reported. Slow evaporation of an aqueous solution containing equimolar quantities of L-proline and succinic acid (for 1) and L-threonine and zinc acetate (for 2) results in the fractional crystallization of succinic acid (in the first case) and L-threonine (in the second case) and not any novel organic non-linear optical (NLO) crystals. In this paper, the usefulness of infrared spectra for correct product characterization is demonstrated.