Thermodynamic Calculations for Reactions Involving Hydrogen Halide Polymers, Ions, and Lewis Acid Adducts. 3. Systems Constituted from Al(3+), H(+), and Cl(-).
Semiempirical (MNDO, AM1 and PM3), ab initio (HF/3-21+G(d,p), MP2/3-21+G(d,p), HF/6-311+G(d,p), and MP2/6-311+G(d,p)), and density functional (BVWN/3-21+G(d,p) and BVWN/6-311+G(d,p)) energy minimization and frequency calculations have been carried out on AlCl(3), AlCl(4)(-), AlCl(2)(+), HAlCl(4), HAlCl(3)(+), and ClHAlCl(4)(-). The same computational set, except for MP2/6-311+G(d,p) frequency calculations, was performed on Al(2)Cl(6) and Al(2)Cl(7)(-). For ClHAl(2)Cl(7)(-), only semiempirical calculations, as well as Hartree-Fock and BVWN optimizations using the 3-21+G(d,p) and 6-311+G(d,p) basis sets, were carried out along with Hartree-Fock frequency determinations. DeltaG degrees, DeltaH degrees, and DeltaS degrees values have been calculated for a number of reactions involving these species along with a variety of ions derived from HCl. Thermodynamic data and equilibrium constants at 298 K are presented for 22 reactions using calculations at the best level, along with a comparison of DeltaG degrees values obtained from all molecular orbital methods used.
Chandler
W. David
WD
Department of Chemistry, University of Regina, Regina, Saskatchewan S4S 0A2, Canada.
Johnson
Keith E.
KE