Interaction of L11 stationary phase (Phenyl, Biphenyl)
Types of interactions
Origin of force
van der Waals force
London dispersion force
Permanent Dipole-Permanent Dipole
Induced dipole-induced dipole
Attenuates at -6th power of distance and makes an important contribution only at short distances. Dispersion is dominant in nonpolar molecules.
Charge transfer interaction
Electron donor-Electron acceptor
Coloring by charge transfer absorption
Functional groups such as OH and NH
Strong specificity and directivity
Non-polar groups in polar solvents
As shown in the figure above, benzene has the highest electron density in the center, and the phenyl and biphenyl groups of the L11 stationary phase have a dipole-dipole interaction, which is the orientation force of the van der Waals force. It then exhibits characteristic selectivity by the π-π and CH-π interactions that are treated as part of them.
★π-π stacking and T-type stacking are known as benzene arrangement states as π-π interactions. It is presumed that T-type stacking is close to the CH-π interaction, which is the interaction between the central part of benzene and hydrogen of CH.