Ab Initio Calculations of Structure and Energetics of the Hypermetalated Hydrogen Oxide Molecules: Li2NaOH and LiNa2OH

Abstract

AbstractWe made ab initio electronic calculations of the structure and energetics of mixed hypermetalated hydrogen oxides, Li2NaOH and LiNa2OH. There exist five equilibrium geometries for each complex. In all levels of calculation the global minimum structure for Li2NaOH has C2v symmetry and a large distance between sodium and oxygen, 4.24 Å (MP2/6‐31G*). The dissociation energies to all possible products were also calculated. Li2NaOH → Na + Li2OH δH = +25.33 kcal/mol (at MP4/6‐311++G**//6‐31G* + ZPE scaled by 0.9). All other dissociation processes are highly endothermic. Similar procedures were applied to LiNa2OH. The global minimum structure for LiNa2OH belongs to point group Cs. It is also endothermic to all possible dissociation paths. LiNa2OH →Na + LiNaOH δH = +12.72 kcal/mol (at MP4/6‐311++G*//6‐31G* + ZPE scaled by 0.9). The nuclear repulsion energy is crucial in energetics of the structures. The distribution of electron density and bonding properties for these equilibrium structures were analyzed.