title: A mechanochemical study of the effects of compression on a Diels-Alder reaction.
abstract: We examine the effects of compressive external forces on the mechanisms of the parent Diels-Alder (DA) reaction between butadiene and ethylene. Reaction pathways and transition states were calculated using the nudged elastic band method within a mechanochemical framework at the CASSCF(6,6)/6-31G**, as well as the B3LYP/6-311++G** levels of theory. Our results suggest that compressive hydrostatic pressure lowers the energy barrier for the parent DA reaction while suppressing the undesirable side reaction, thereby leading to a direct increase in the yield of cyclohexene. Compressive pressure also increases the exothermicity of the parent DA reaction, which would lead to increased temperatures in a reaction vessel and thereby indirectly increase the yield of cyclohexene. Our estimates indicate that the compression used in our study corresponds to a range of 68 MPa-1410 MPa.
authors.affiliation: School of Polymers and High Performance Materials, University of Southern Mississippi, Hattiesburg, Mississippi 39402, USA.
authors.forename: Sanjiv K
authors.initials: SK
authors.lastname: Jha
authors.affiliation: Department of Polymer and Fiber Engineering, Auburn University, Auburn, Alabama 36849, USA.
authors.forename: Katie
authors.initials: K
authors.lastname: Brown
authors.affiliation: School of Polymers and High Performance Materials, University of Southern Mississippi, Hattiesburg, Mississippi 39402, USA.
authors.forename: Guido
authors.initials: G
authors.lastname: Todde
authors.affiliation: School of Polymers and High Performance Materials, University of Southern Mississippi, Hattiesburg, Mississippi 39402, USA.
authors.forename: Gopinath
authors.initials: G
authors.lastname: Subramanian