Theories of Hydrogen Bond Formation

Modern discussions of an electrostatic model of the H bond are more sophisticated than the earliest point charge calculations. Theorists believe that the charge distribution of the nonbonded electrons must be 

For example, Lennard-Jones and Pople proposed that the electrostatic description of the H bond of water should be as shown in Fig. 8-2 (1210, 1659). The charges were placed so as to give the correct dipole moment, and then the electrostatic energy was calculated. The resulting 

FIGURE 8-2 Lennard-Jones and Pople electrostatic model for H bonded water (as applied by Schneider, 1812). 

Schneider proceeds with a detailed treatment based on point charges placed at the centroids of charge of hybridized nonbonding orbitals. 

For carbonyl bases the angle of interest falls in the range 99-120 . When the base is the oxygen in an hydroxyl group, the angle varies from 90 to 135 . 

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