Ultrasonic Studies of Nd³⁺: L-Tryptophan Amino Acid Complexes

The present study aims at the study of ultrasonic properties in L-tryptophan amino acid complexes of varying concentrations of Nd³⁺ (0.1, 0.25, 0.5, 1.0 and 2.0 mol %) doped in aqueous solutions of L-tryptophan amino acid complexes. Experimental values of density and ultrasonic velocities were determined for all the complexes under study. The data thus obtained have been used to estimate the ultrasonic characteristic parameters such as velocity (u), free length (Lf), isothermal compressibility (β_T), isentropic compressibility (K_S), thermal expansion coefficient (α) and acoustic impedance (Z) for all these complexes. These parameters have been analyzed and eventually emphasizing the possible molecular interactions in terms of structure-making and structure-breaking effects of the above amino acid complexes. The variation in the concentrations of Nd³⁺ ions in the L-tryptophan exhibit linear relationship with the above ultrasonic parameters. Therefore it is optimistic to control these ultrasonic parameters using the Nd³⁺ ions in the complexes.