2 research outputs found
Predicting the Efficiency of Photoswitches Using Force Analysis
Photoswitches
convert light into mechanical energy by exerting
forces on their environment during photoisomerization. However, the
mechanical efficiency of this conversion is limited because a plethora
of internal modes of the photoswitch do not contribute to the desired
switching function but are also changed during the photoisomerization.
Here we present a computational approach to quantify the efficiency
of a photoswitch during the initial motion on the excited-state potential
energy surface. We demonstrate the gist of our method by looking at
the excited-state relaxation of carbon monoxide. Subsequently, the
photoswitching efficiency of <i>p</i>-coumaric acid is analyzed
as one representative example of the approach
Can Strained Hydrocarbons Be āForcedā To Be Stable?
Many
strained hydrocarbons are prone to isomerization, dimerization,
and trimerization under normal laboratory conditions. Here we investigate
a method to stabilize angle-strained cycloalkynes by applying a mechanical
pulling force to the carbon atoms adjacent to the triple bond, which
partially linearizes the Cī¼CāC bond angles. We discuss
various methods of applying such pulling forces, including photoswitches
and incorporation into additional strained macrocycles. We use the
computational JEDI (Judgement of Energy DIstribution) analysis to
quantify the distribution of energy in strained cycloheptyne and judge
the change in stability upon application of an external force via
isodesmic and homodesmotic reactions. We find that cycloheptyne can
indeed be stabilized by external forces. However, the force generated
by photoswitches during isomerization is too low to lead to a significant
stabilization of the molecule. Hence, stronger forces are needed,
which can be achieved by incorporating cycloheptyne into a second
strained macrocycle