Energetics of hydride and electron pair attachment to EX3 0/+ (E=B, C, Al, Si and X=F, Cl, Br, I) and the study of bonding trends among EX3 0/+, EX3 2−/−, and EX3H−/0 by use of ELF and NBO analyses

A theoretical gas-phase “ligand-free” or “electron pair affinity” (EPA) approach, based on CCSD(T)/(SDB-)cc-pVTZ//MP2/(SDB-)cc-pVTZ electronic structure calculations, is introduced as a possible means for determining Lewis acidity trends among planar EX3 0/+ (E=B, C, Al, Si; X=F, Cl, Br, I) species. In this treatment, the free electron pair is considered to be an extreme Lewis base. The calculated EPA values are compared with experimental Lewis …