Abstract.
The application of the Principal Component of Analysis (PCA) over the
theoretical data of a series of substituted 1,3-oxazines helps to determine
the factors that rule the conformational equilibrium. Repulsive and intertribal
syn-1,3-diaxial interactions have been used as determiners for the axial
structures, whereas dipolar interactions are preferred in the equatorial
conformation. Theoretical variables such as hardness, charges, nuclear
repulsion energy and bond order in the different nuclear sectors have been
used. PCA method has been successfully used in predicting the hyperconjugative
interactions that play an important role in the conformational equilibrium
between a given pair of conformers of 1,3-oxazines. The studied 1,3-oxazines
belong to three different groups of structures having the heterocyclic
ring as a common feature. The axial structures are stabilized by two-electron/two-orbital
interactions, whereas the equatorial structures are believed to be stabilized
by syn-1,3-diaxial and dipole-dipole interactions
Keywords.
PCA Analysis; Oxazines; Abinitio Methods.
Keywords Plus.