Tuning Molecular Solar Thermal Properties by Modification of a Promising Norbornadiene Photoswitch
Journal article, 2019

Carefully targeted modifications to the norbornadiene-quadricyclane couple should give molecules with great potential for solar energy storage. Here we report the synthesis of derivatives of a well-studied compound, 2-cyano-3-anisyl norbornadiene (NBD5). The conjugation was extended by conversion of the nitrile into acrylonitrile and acrylate derivatives over two steps. Despite red-shifting the absorbance properties, the metastable quadricyclanes exhibited extremely short lifetimes. Meanwhile, treatment of NBD5 with acetyl halides in the presence of aluminum trihalides led to the formation of 7-acetyl norbornenes through a Wagner–Meerwein rearrangement. Subsequent transformations made it possible to synthesise norbornadienes with varying degrees of steric bulk at the 7-position of the molecular scaffold. It was found that the bulkier this group was, the more stable the quadricyclane form. This reaction sequence allows for the synthesis of norbornadiene derivatives which are more suited to molecular solar thermal applications in domestic heating despite providing a slightly lower energy density.

Conjugation

Photochromism

Strained molecules

Energy density

Wagner–Meerwein rearrangement

Author

Martyn Jevric

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Kasper Moth-Poulsen Group

Zhihang Wang

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Kasper Moth-Poulsen Group

Anne Petersen

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Kasper Moth-Poulsen Group

Mads Manso

University of Copenhagen

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Kasper Moth-Poulsen Group

Christopher Sumby

University of Adelaide

M. B. Nielsen

University of Copenhagen

Kasper Moth-Poulsen

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Kasper Moth-Poulsen Group

European Journal of Organic Chemistry

1434-193X (ISSN)

Vol. 2019 13 2354-2361

Subject Categories

Materials Chemistry

Theoretical Chemistry

Organic Chemistry

DOI

10.1002/ejoc.201801781

More information

Latest update

4/29/2019