The remarkably invariant interaction energies of lithium first-row compounds with water and with ammonia
✍ Scribed by Elmar Kaufmann; Bruce Tidor; Paul Von Ragué Schleyer
- Publisher
- John Wiley and Sons
- Year
- 1986
- Tongue
- English
- Weight
- 810 KB
- Volume
- 7
- Category
- Article
- ISSN
- 0192-8651
No coin nor oath required. For personal study only.
✦ Synopsis
Solvation energies of lithium first-row compounds LiX (X = H, Li, BeH, BH2, CH3, NH2, OH, F) and of the lithium cation with the model solvents, water and ammonia, have been calculated ab inito (MP2/6-31 +G*//6-31G* with zero-point vibrational energy corrections at 3-21G//3-21G). The solvation energies are found to be remarkably constant: -18.0 5 1.2 and -21.5 5 1.3 kcal/mol for the hydrates and ammonia solvates, respectively. This independence on the nature of X is due largely to the ionic character of the LiX compounds (dipole moments 4.7-6.6 debye). The unexpectedly high solvation energies of the lithium molecule (-14.3 and -17.8 kcal/mol, respectively) are due to the polarizability of Liz. At the same level, the lithium cation has interaction energies with H20 and NH, of -34.1 and -39.7 kcal/mol, respectively. For the hydrates of LiOH and LiF cyclic structures with hydrogen bonds and somewhat increased solvation energies also are described.