The Importance of Hydrogen Bonds in Crystals

It is possible to understand this dominance of the H bond in terms of the energy of molecular interactions. The heats of sublimation of most organic crystals are determined by van der Waals interactions with energies of the order of several hundred calories per carbon atom. But if a H bond can be formed, the stability of a molecular crystal can be 

TABLE 9-1 Heats of Sublimation and Melting Points of Some Molecular Crystals 

A final bit of evidence strongly suggestive of the importance of H bonding in crystal formation is the collection of heats of sublimation presented in Fig. 7-2. These data, also compiled by Davies (480), display differences which invite an obvious though possibly deceptively simple interpretation. 

Of course the strong interactions present in H bonded crystals are reflected in other physical properties, such as melting point, dielectric behavior, electrical conductivity, and piezoelectric behavior. The 

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