Reversible trans⇌cis photoisomerizations of [Re(CO) 3 (ph 2 phen)(stpyCN)] + towards molecular machines

• Published in: Dalton transactions : an international journal of inorganic chemistry Vol. 46; no. 30; pp. 9951 - 9958
• Main Authors: Zanoni, Kassio P S, Murakami Iha, Neyde Y
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 14.08.2017
• Subjects: Chemistry
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/c7dt01648d

In our search for light powered molecular devices, a novel fac-[Re(CO) (ph phen)(trans-stpyCN)] complex was synthesized to show switchable trans-cis configurations of the coordinated stpyCN ligand through efficient and reversible photoassisted isomerizations. Controlled photolyses of acetonitrile solutions led to spectral changes ascribed to reversible trans⇌cis photoisomerization processes. A remarkable quantum yield for the back cis-to-trans isomerization was obtained, with the same magnitude of the trans-to-cis photoprocess, and curiously, both trans- and cis-isomers are emissive at room temperature. Photochemical and photophysical characterization studies for fac-[Re(CO) (ph phen)(stpyCN)] provided insights into the isomerization and emissive light-driven pathways that are resulted from the interactions between the close-lying intraligand and charge transfer states. The reversible cis-trans photoisomerization has potential to be exploited as light-powered molecular motors and geometry regulators in molecular machines.