Hydrolysis mechanism of double six–membered ring pentaborate anion

• DOI: 10.1016/j.cplett.2019.136930
• Publication Date: 2019-11-05T00:41:44Z
• Authors: Hong-Xia Zhou; Fa-Yan Zhu; Hong-Yan Liu; Wen-Qian Zhang; Yong-Quan Zhou; Chun-Hui Fang; Hai-Bei Li
• Keywords: 01 natural sciences; 0104 chemical sciences

Abstract DFT-based calculations show that B5O6(OH)4- forms B5O5(OH)6− intermediate during the first step of hydrolysis. Then, the hydrolysis pathways are divided to principal and secondary reactions. In the principal reaction, hydrolysis occurs at the bridge position between the six-membered ring and branch BO3 units to form B(OH)3 and B3O3(OH)4−. B3O3(OH)4− hydrolyzes in dilute solution to B(OH)3 and B(OH)4−. In the secondary reaction, hydrolysis of B5O5(OH)6− occurs at the bridge position in the ring to form a “network-chain” structure B5O4(OH)8−. Then, hydrolysis occurs at the bridge atoms, each BO3 unit is converted to B(OH)3, and BO4 unit is finally converted to B(OH)4−.