Automated Variable Electric-Field DFT Application for Evaluation of Optimally Oriented Electric Fields on Chemical Reactivity

Recent theoretical work and experiments at molecular
junctions
have provided a strong conceptualization for the effects of oriented
electric fields (OEFs) on organic reactions. Depending on the axis
of application, OEFs can increase (or decrease) the reaction rate
or distinguish between isomeric pathways. Despite the conceptual elegance
of OEFs, which may be applied externally or induced locally, as tools
for catalyzing organic reactions, implementation in synthetically
relevant systems has been hampered by inefficiencies in evaluating
reaction sensitivity to field effects. Herein, we describe the development
of the Automated Variable Electric-Field DFT Application (A.V.E.D.A.)
for streamlined evaluation of a reaction’s susceptibility to
OEFs. This open-source software was designed to be accessible for
nonexpert users of computational and programming tools. Following
initiation by a single command (and with no subsequent intervention)
the Linux workflow manages a series of density functional theory calculations
and mathematical manipulations to optimize local-minimum and transition-state
structures in oriented electric fields of increasing magnitude. The
resulting molecular and reaction dipole moments, field-perturbed geometries,
and net effective activation energies are compiled for user interpretation.
Ten representative pericyclic reactions that showcase the development
and evaluation of A.V.E.D.A. are described.