Conformational bias in density functional theory ring strain energy calculations of cyclopentene derivatives: Towards predictive design of chemically recyclable elastomers.

Autor: Coia, Brianna M., Werner, Sarah E., Kennemur, Justin G.
Předmět:
Zdroj: Journal of Polymer Science; Dec2022, Vol. 60 Issue 24, p3391-3403, 13p
Abstrakt: Equilibrium ring opening metathesis polymerization of low strained cycloolefins is opportunistic for the development of novel materials capable of chemical recycling to monomer (CRM). However, many of the potential materials for CRM contain complex side chains complicating predictions of their ring strain energies (RSE). The effects of different conformational considerations on RSE predictions using density functional theory (DFT) are explored. New homodesmotic equations are investigated to capture changes in olefin conformation upon polymerization. The employment of cis‐2‐butene as a corrective factor with a 2,7‐nonadiene linear analog bearing one cis and one trans olefin (H2cis) resulted in RSEs similar to previously reported ΔHp values. Different consideration of possible conformers aside from their lowest energy counterparts leads to a range of predicted RSE values. Similarly, the application of a Boltzmann distribution resulted in negligible differences in RSE. Therefore, RSE predictions using the lowest energy structures with H2cis calculated at B3LYP/6‐31+G* in toluene is a sufficient approach for predicting RSE of monomers with multiple conformers. This method can be used to screen a monomer's potential for CRM to reduce the time, cost, waste, and effort necessary to research new materials towards a more circular polymer economy. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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