The molecular photochromic switch 1,2-bis(2,4-dimethyl-5-phenyl-3-thienyl)perfluoro-cyclopentene, abbreviated as DMPT-PFCP, has been commanding much attention recently in the fields of nanotechnology and optical data storage for 2D and 3D media applications. This recent attention of DMPT-PFCP is mainly attributed to the diarylethene’s high optical fatigue resistance and photo-isomerative nature, which allows the molecule to assume open and closed-ring conformations when irradiated with visible or UV light, respectively. Since it has been found that not all open-ring conformations of DMPT-PFCP can be readily converted to their closed-ring isomers upon photo-excitation, quantum yield for the photo-isomerization process has been limited to only ~50%. This ~50% quantum yield can be attributed to the existence of two classes of open-ring conformations of DMPT-PFCP in the ground-state: reactive (R) and non-reactive (NR). In order to better understand the photo-isomerization process, we utilize Time-Dependent Density Function Theory (TD-DFT) to study the photo-physical pathways of the open-ring, ground-state conformers of DMPT-PFCP to identify factors that promote or inhibit electrocyclization of the molecule. We have found that reactive conformers decay non-radiatively through conical intersections allowing for optimal photo-isomerization, whereas non-reactive conformers have large barriers on the S1 pathway that inhibit photo-isomerization upon UV excitation. Through this fundamental understanding of DMPT-PFCP, experimental procedures can be modified, when creating optical data storage devices, in order to provide more efficient means of data storage for the advancement in nanotechnology.

Study of the structural rearrangement and electrocyclization pathway of a diarylethene derivative

251st National Meeting (2016)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.