Table 5. Weak Hydrogen Bond Energies for Diamondoid Solids.
| crystal solid | ΔHf(m)a(kcal/mol) | ΔHf(s)b(kcal/mol) | ΔHIPc(kcal/mol) | ΔHHd(kcal/mol) |
|---|---|---|---|---|
| Tetrakis(4-ethynylphenyl)methane | ||||
| PM3 | 321.10 | 316.26 | –4.84 | –1.21 |
| AM1 | 336.15 | 334.48 | –1.67 | –0.42 |
| Tetraethynylmethane | ||||
| PM3 | 211.75 | 207.40 | –4.35 | –1.09 |
| AM1 | 228.77 | 226.81 | –1.96 | –0.49 |
| Tetrabutadiynylmethane | ||||
| PM3 | 419.42 | 415.75 | –3.67 | –0.92 |
| AM1 | 436.06 | 434.61 | –1.45 | –0.36 |
a
The heat of formation for the monomer.
b
The heat of formation for the solid.
c
The total interaction energy.
d
The net interaction energy per weak hydrogen bond.