Quantitative Structure-activity Relationship Models of Monomer Reactivity

The reactivity parameters, Q and e, in the Q-e scheme reflect the reactivities of a monomer (or a radical) in free-radical copolymerizations. By applying multiple linear regression (MLR) analysis, the optimal quantitative structure-activity relationship (QSAR) model for the reactivity parameter lnQ was developed based on five descriptors (N-AF, N-OF, E-alpha LUMO, E-beta HOMO, and E-beta LUMO) and 69 monomers with the root mean square (rms) error of 0.61. The optimal MLR model of the parameter e obtained from five descriptors (T-Ocl, N-pN, N-SO, E-alpha HOMO and D-H) and 68 monomers produced rms error of 0.42. Compared with previous models, the two optimal MLR models in this paper show satisfactory statistical characteristics. The feasibility of combining 2D descriptors obtained from the monomers and 3D descriptors calculated from the radical structures (formed from monomers + H center dot) to predict parameters Q and e has been demonstrated.