Solute-Stationary Phase Interaction in Gas Liquid Chromatography. Relative Retention Values for Monosubstituted Benzene Derivatives and the Role of a New Descriptor for Regression Analysis

The descriptor μ 2 /α was introduced by the classical equations for the orientation and induction energies. As the descriptor has the dimension of energy, it is not convenient to discuss in detail. The dipole moment in the benzene series μ aro is evaluated from both the bond moment μ b and the mesomeric moment μ m , We redefine the new descriptors σ bd and σ ms modified to dimensionless values from μ b and μ m for the standard benzene as well as the descriptor σ s . The relative retention values log γ on monosubstituted benzene derivatives are analyzed satisfactorily, using σ s , σ bd , and σ ms + for electron-donating group, and a new descriptor (σ s . σ bd ) 1/2 (N), which has a relation to the dipole moment of the excited state in C ipso -N bond of the aniline series. log γ=4.414(0.561)σ s +0.209(0.042)σ bd +0.336(0.153)σ ms + +1.592(0.441)(σ s' .σ bd ) 1/2 (N)+0.004(0.096) n=22, r=0.981, F=110.21, S.D.=0.064 It is suggested that E HB of aniline or N,N-dimethylaniline can be expressed by E ES in gaseous interaction