Coordination‐Driven Macrocyclization for Locking of Photo‐ and Thermal cis→trans Isomerization of Azobenzene. Issue 49 (8th October 2014)

• Record Type: Journal Article
• Authors: Yamamura , Masaki; Yamakawa, Koji; Okazaki, Yuki; Nabeshima , Tatsuya
• Is Part Of: Chemistry. Volume 20:Issue 49(2014)
• Page Start: 16258
• Page End: 16265
• Publication Date: 2014-10-08
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201404620
• Languages: English
• ISSNs: 0947-6539

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Both <italic>trans</italic> and <italic>cis</italic> isomers of azobenzene‐linked bis‐terpyridine ligand <bold>L1</bold> were incorporated in rigid macrocycles linked by Fe^II(tpy)₂ (tpy: terpyridine) units. The complex of the longer <italic>trans</italic>‐<bold>L1</bold> is dinuclear [(<italic>trans</italic>‐<bold>L1</bold>)₂<bold>⋅</bold>Fe^II₂], whereas the complex of the shorter <italic>cis</italic>‐<bold>L1</bold> is mononuclear [<italic>cis</italic>‐<bold>L1⋅</bold>Fe^II]. The complex <italic>cis</italic>‐<bold>L1⋅</bold>Fe^II was not only thermally stable but also photochemically inactive. These results indicate a perfectly locked state of <italic>cis</italic>‐azobenzene. The stable macrocyclic structure of <italic>cis</italic>‐<bold>L1⋅</bold>Fe^II causes locking of the isomerization. To the best of our knowledge, this is first example of dual locking of photo‐ and thermal isomerization of <italic>cis</italic>‐azobenzene.</p> </abstract>