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Photoisomerization of Bis(tridentate) 2,6‐Bis(1 H ‐pyrazol‐1‐yl)pyridine Ligands Exhibiting a Multi‐anthracene Skeleton
Author(s) -
Šalitroš Ivan,
Fuhr Olaf,
Gál Miroslav,
Valášek Michal,
Ruben Mario
Publication year - 2017
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201700825
Subject(s) - anthracene , isostructural , chemistry , intramolecular force , pyridine , stereochemistry , crystal structure , crystallography , photochemistry , medicinal chemistry
A novel molecular design is described where two peripheral moieties made of 2,6‐bis(1 H ‐pyrazol‐1‐yl)pyridine are linked through multi‐1,8‐diethynylanthracene moieties. The optimized synthesis of the three isostructural analogues 1 a , 1 b , and 1 c , containing the anthraquinone, anthracene, and 10‐methoxyanthracene units, respectively, is reported. The resulting spatial face‐to‐face arrangement of the peripheral anthracene rings enables to trigger the intramolecular [4+4] photocycloaddition affording the isomers P1 b and P1 c , which can be thermally cleaved back to the original anthracene derivatives 1 b and 1 c , respectively. Single‐crystal X‐ray diffraction studies confirm the expected molecular structures of compounds 1 a – 1 c as well as of their corresponding isomers P1 b and P1 c . The spectral, optical, and electrochemical properties of all synthesized compounds are investigated and discussed.