Substrate‐Bound Diarylethene‐Based Anisotropic Metal–Organic Framework Films as Photoactuators with a Directed Response
Yunzhe Jiang, Yidong Liu, Sylvain Grosjean, Volodymyr Bon, Patrick Hodapp, Anemar Bruno Kanj, Stefan Kaskel, Stefan Bräse, Christof Wöll, Lars Heinke
Abstract
Molecular machines and responsive materials open a plethora of new opportunities in nanotechnology. We present an oriented crystalline array of diarylethene (DAE)-based photoactuators, arranged in a way to yield an anisotropic response. The DAE units are assembled, together with a secondary linker, into a monolithic surface-mounted metal-organic framework (SURMOF) film. By Infrared (IR) and UV/Vis spectroscopy as well as by synchrotron X-ray diffraction, we show that the light-induced extension changes of the molecular DAE linkers multiply to yield mesoscopic and anisotropic length changes. Due to the special architecture and substrate-bonding of the SURMOF, these length changes are transferred to the macroscopic scale, leading to the bending of a cantilever and performing work. This research shows the potential of assembling light-powered molecules into SURMOFs to yield photoactuators with a directed response, presenting a path to advanced actuators.