Empirical prediction of heats of formation and of redistribution of boron compounds using nonbonded interaction energy terms from redistribution equilibriums

Thermodynamics of Boroxine Formation from the Aliphatic Boronic Acid Monomers R–B(OH)2 (R = H, H3C, H2N, HO, and F): A Computational Investigation

“…arguably making the value of À565.3 kcal/mol (Table4SA, Supporting Information) listed in the JANAF compilation 92 the most reliable experimentally based heat of formation currently available for any boroxine derivative. Using the heat of formation for FÀB(OH) 2 suggested by Elkaim et al,114 À249.6 kcal/mol (Table2SB, Supporting Information), gives a value for ΔH rand þ10.6 kcal/mol for these calculations, in good agreement with the value of ΔH r (298 K). Although this reaction is favored entropically by ∼6.4 kcal/mol, the calculated values of ΔG 298…”

“…The need for thermal data on F-B-O systems by workers in the fields of solid and liquid propellants around 1960 led to numerous determinations of the heat of formation of F 3 B 3 O 3 97 , arguably making the value of −565.3 kcal/mol (Table 4SA) listed in the JANAF compilation 92 the most reliable experimentally-based heat of formation currently available for any boroxine derivative. Using the heat of formation for F–B(OH) 2 suggested by Elkaim et al 114 , −249.6 kcal/mol (Table 2SB), gives a value for ΔH r (298 K) for the dehydration reaction of +10.1 kcal/mol, in quite good agreement with the MP2/aug-cc-pVTZ value; using the Sanderson value 95,115 , for the heat of formation of F–B(OH) 2 gives a slightly higher value for ΔH r (298 K), +10.4 kcal/mol. Using MP2/aug-cc-pVTZ optimized geometries, we carried out single point calculations for F–B(OH) 2 , F 3 B 3 O 3 , and H 2 O at the MP2/aug-cc-pVQZ, MP2/aug-cc-pV5Z, CCSD/aug-cc-pVTZ, and CCSD(T)/aug-cc-pVTZ levels; the resulting values of ΔE are +14.5, +14.7, +13.8, and +13.5 kcal/mol, respectively.…”

Monosubstituted Phenylboronic Acids, R–B(OH)2 (R = C6H5, C6H4CH3, C6H4NH2, C6H4OH, and C6H4F): A Computational Investigation

“…To the authors’ knowledge there is no direct experimental value available for the HOF of PBA. However, two estimates of ∆H f (298.15K) have been given in the literature, −151.77 kcal/mol [71] and −152.26 kcal/mol [71, 72], based on energy decomposition schemes. The calculated G3 values of ∆H f (298.15K) for the endo-exo form, −136.4 kcal/mol, is significantly less negative than the literature estimates, see Table 2.…”