title: Surface and Bulk Effects in Photochemical Reactions and Photomechanical Effects in Dynamic Molecular Crystals.
abstract: The increasing number of reports on photomechanical effects in molecular crystals necessitates systematic studies to understand the intrinsic and external effectors that determine and have predictive power of their type and magnitude. Differential light absorption and product gradient between the surface and the bulk of the crystal are often invoked to qualitatively explain the mechanical response of crystals to light; however, the details on how this difference in photochemical response accounts for macroscopic effects such as surface modification, deformation, or disintegration of crystals are yet to be established. Using both bulk- and surface-sensitive analytical techniques, a rare instance of benzylidenefuranone crystals is studied here, and it is capable of several distinct types of photomechanical response including surface striation and delamination, photosalient effect (ballistic disintegration and motion), and photoinduced bending by dimerization. The results provide a holistic view on these effects and set the stage for the development of overarching theoretical models to describe the photomechanics in the ordered solid state.
authors.affiliation: New York University Abu Dhabi , P. O. Box 129188, Abu Dhabi, United Arab Emirates.
authors.forename: Naba K
authors.initials: NK
authors.lastname: Nath
authors.affiliation: Max Planck Institute for Solid State Research , Heisenbergstrasse 1, D-70569 Stuttgart, Germany.
authors.forename: Tomče
authors.initials: T
authors.lastname: Runčevski
authors.affiliation: Masdar Institute of Science and Technology , P. O. Box 54224, Abu Dhabi, United Arab Emirates.
authors.forename: Chia-Yun
authors.initials: CY
authors.lastname: Lai
authors.affiliation: Masdar Institute of Science and Technology , P. O. Box 54224, Abu Dhabi, United Arab Emirates.
authors.forename: Matteo
authors.initials: M
authors.lastname: Chiesa
authors.affiliation: Max Planck Institute for Solid State Research , Heisenbergstrasse 1, D-70569 Stuttgart, Germany.
authors.forename: Robert E
authors.initials: RE
authors.lastname: Dinnebier
authors.affiliation: New York University Abu Dhabi , P. O. Box 129188, Abu Dhabi, United Arab Emirates.
authors.forename: Panče
authors.initials: P
authors.lastname: Naumov