EXPERIMENTAL MOLECULAR STRUCTURES

Summary The synthesis and characterization of a stable P-bis-silyl-substituted vinyl cation is reported. Its spectral properties and its experimental molecular structure clearly reveal the consequences of Si-C hyperconjugation. 

Thus, although this review is primarily about the intermolecular forces in organic crystal structures, the problems of balancing inter- and intramolecular forces is clearly a major aspect of the challenge that crystal structure prediction poses computational chemistry. It is also important to appreciate that tests of intermolecular potentials for crystal structure prediction and reproduction will be significantly more successful when the experimental molecular structure is used than when genuine predictions are made. 

This general property of 10- and 12-vertex clusters is illustrated in Figure 14.6 with a series of carboxylic acids substituted with a propyl group. The conformations in Figure 14.6 are consistent with experimental molecular structures of mesogenic derivatives and relative stability of the mesophase in isostructural derivatives. 

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