Shella Permatasari Santoso, Artik Elisa Angkawijaya, Felycia Edi Soetaredjo, Suryadi Ismadji, Yi-Hsu Ju
Equilibrium studies of beryllium with 2,3-dihydroxybenzoic acid, 3,4-dihydroxybenzoic acid and gallic acid in an aqueous solution at 310.15 K, an ionic strength of 0.15 mol·dm- 3 NaCl and pH 2.5 to 11.0 were investigated by the pH-potentiometric method. Stability constants of the complexes were determined by HyperQuad2008 and presented as logβ. Contributing binding sites of these ligands were evaluated by comparing its logβ with some structurally related ligands such as catechol and salicylic acid. Spectrophotometric measurements were done to confirm the formation of the complex species. Geometry optimization and frequency analysis of the complexes were performed by using Gaussian09W program to verify the contributing binding sites. The results indicate that the ability of ligands in preventing the hydrolysis of Be2 + follows the order: 3,4-dihydroxybenzoic acid > 2,3-dihydroxybenzoic acid > gallic acid. © 2015 Elsevier B.V. All rights reserved.
Chemical Engineering Department, National Taiwan University of Science and Technology, Taipei, 106-07, Taiwan; Department of Chemical Engineering, Widya Mandala Surabaya Catholic University, Kalijudan 37, Surabaya, 60114, Indonesia