Thiol‐Ene Polymerization of Natural Monomers: A DFT Study

AbstractThis study investigates the thiol‐ene reaction mechanism of natural monomers using quantum chemical tools. The structure‐reactivity relationship for these monomers is elaborated by the aid of radical stabilization energies (RSEs), intermolecular interactions, the curve‐crossing model, Hammond Postulate, and Evans–Polanyi relationships. Geometry optimizations, frequency, and energy calculations are performed at the M06‐2X/6‐31++G(d,p) level of theory. A crucial parameter for thiol‐ene polymerization, which is the ratio of the propagation reaction (kp) and the chain transfer reaction (kct) rate constants (kp/kct), is calculated in order to elucidate the thiol‐ene reaction mechanism. In light of these energetic and kinetic calculations, it is suggested that linalool, d‐limonene, terpinolene, and γ‐terpinene are considered natural monomer candidates for thiol‐ene polymerization due to their almost equal magnitude of the rate constants (kp/kct≈1). The thiol‐ene polymerization potential of some specific unsaturated fatty acids is another prominent finding in this study.