Density Functional Theory Simulations of Aluminium Alkoxide and Fluoride

Apichai Jomphoak, Thawatchai Onjun, Kenta Hongo, Ryo Maezono

A series of density functional theory (DFT) simulations was carried out to investigate the geometry and reaction pathways of aluminium alkoxides using three different exchange-correlation functionals, including the local-density approximation, generalized gradient approximation, and a hybrid functionals. The simulations of fluoride atoms (F) sticking to the Al alkoxide, varying their distances from 6.0 Å to their intermediate states along a straight line for the corresponding energy surfaces, were performed. It is found that the structural optimization obtained from different exchange-correlation functionals exhibits similar molecular configurations. The reaction pathways for the synthesis of Al fluoride was also simulated by utilizing the transition state searches method for investing the reaction pathways, including linear synchronous (LST) and quadratic synchronous (QST) maximization to investigate the reaction intermediate, and the converged results for all the distances were successfully obtained. It is found that the F atom replace one of bridging and terminal isopropoxide groups at the final state equivalently converted to the surrounded solvent molecules.