Efficient Cyclization of the Norbornadiene‐Quadricyclane Interconversion Mediated by a Magnetic [Fe3O4−CoSalphen] Nanoparticle Catalyst. Issue 1 (30th August 2019)

• Record Type: Journal Article
• Authors: Luchs, Tobias; Lorenz, Patrick; Hirsch, Andreas
• Is Part Of: ChemPhotoChem. Volume 4:Issue 1(2020)
• Page Start: 52
• Page End: 58
• Publication Date: 2019-08-30
• Subjects: catalysis -- magnetic properties -- nanoparticles -- photoswitch -- solar energy storage; Photochemistry -- Periodicals; Periodicals; Electronic journals; 541.35
• DOI: 10.1002/cptc.201900194
• Languages: English
• ISSNs: 2367-0932

Abstract

Abstract: We report a novel, inexpensive and effective process for the repeatable photoisomerization of norbornadiene (NBD) to its metastable isomer quadricyclane (QC), followed by catalytically induced strain energy release via back‐conversion of QC to NBD. By utilization of a quasi‐homogeneous catalyst based on magnetic core‐shell nanoparticles, tedious purification steps are avoided. The core of this material is comprised of Fe3 O4 and a catalytically active cobalt(II) complex is anchored on the particle surface as a self‐assembled monolayer (SAM). These core‐shell nanoparticles [Fe3 O4 −CoSalphen] combine a high surface area of catalytically active molecules with straightforward separation by the action of an external magnetic field. In combination with the promising interconversion couple NBD1‐QC1, which features outstanding stability ( t 1/2 =450 days at room temperature) and a high energy storage potential (88.34 kJ/mol), the nanoparticle catalyst [Fe3 O4 −CoSalphen] shows great potential for technical applications in molecular solar thermal (MOST) energy‐storage systems. Abstract : Switch magnet : This work combines the promising NBD1‐QC1 couple (that features outstanding stability t 1/2 ≈450 days at RT and a high energy storage potential of 88.3 kJ/mol) with a magnetic core‐shell nanoparticle catalyst for the back‐conversion of QC1 (QC=quadricyclane) to NBD1 (NBD=norbornadiene). NBD1 and QC1 can be reversibly interconverted without the need for purification steps, since facile separation via the action of an external magnetic field is possible.