Clustering of HClO4 with Bronsted (H2SO4, HClO4, HNO3) and Lewis acids BX3 (X = H, F, Cl, Br, OH) : a DFT study

摘要: HClO4 is an important catalyst in organic chemistry, and also acts as a reservoir or sink species atmospheric chlorine chemistry. In this study, we computationally investigate the interactions of Bronsted (H2SO4, HClO4, HNO3) Lewis acids (BH3, BF3, BCl3, BBr3, B(OH)3) with using ωB97xD method aug-cc-pVDZ basis set. Different isomers clusters up to 4 molecules (tetramer) were optimized, most stable structures determined. The enthalpies, ΔH, Gibbs free energies, ΔG, cluster formation calculated gas phase at 298 K. Atoms (AIM) calculations find B–O bond critical points only (BH3)nHClO4 clusters, while other was based on hydrogen bonding interactions. (H2SO4)HClO4 (B(OH)3)HClO4, enthalpies −14.1 −12.0 kcal mol−1, stable, (BCl3)HClO4 enthalpy −2.9 least among dimers. Clustering enhanced its acidity, so that clustering four (HClO4)4 increases acidity by about 35 mol−1. acidic dimer found study (BBr3)HClO4, ΔHacid 275 mol−1; 26 mol−1 stronger than monomer.