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(Azulene‐1,3‐diyl)‐bis(nitronyl nitroxide) and (Azulene‐1,3‐diyl)‐bis(iminonitroxide) and Their Copper Complexes
Author(s) -
Haraguchi Makoto,
Tretyakov Evgeny,
Gritsan Nina,
Romanenko Galina,
Gorbunov Dmitry,
Bogomyakov Artem,
Maryunina Kseniya,
Suzuki Shuichi,
Kozaki Masatoshi,
Shiomi Daisuke,
Sato Kazunobu,
Takui Takeji,
Nishihara Sadafumi,
Inoue Katsuya,
Okada Keiji
Publication year - 2017
Publication title -
chemistry – an asian journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.18
H-Index - 106
eISSN - 1861-471X
pISSN - 1861-4728
DOI - 10.1002/asia.201701085
Subject(s) - intramolecular force , antiferromagnetism , azulene , chemistry , nitroxide mediated radical polymerization , ferromagnetism , crystallography , spins , stereochemistry , copper , exchange interaction , photochemistry , condensed matter physics , physics , polymerization , organic chemistry , polymer , radical polymerization
In contrast to diradicals connected by alternant hydrocarbons, only a few studies on those connected by nonalternant hydrocarbons have been reported. The syntheses, structures, and magnetic properties of azulene‐1,3‐diyl linked bis(nitronyl nitroxide) (NN 2 Az) and bis(iminonitroxide) (IN 2 Az) diradicals and their Cu(hfac) 2 (hfac=hexafluoroacetylacetonate) complexes were investigated. NN 2 Az was shown to have an intramolecular ferromagnetic interaction with J obs / k B =+10.0 K ( H =−2 J S 1 ⋅S 2 ) between (nitronyl nitroxide) spins, whereas IN 2 Az was estimated to have a much weaker intramolecular magnetic interaction. The reactions of NN 2 Az and IN 2 Az with Cu(hfac) 2 gave a 1:2 [{Cu(hfac) 2 } 2 (NN 2 Az)] complex and a 1:1 [Cu(hfac) 2 (IN 2 Az)] ⋅ C 6 H 12 complex, respectively. [{Cu(hfac) 2 } 2 (NN 2 Az)] showed strong intramolecular antiferromagnetic interactions ( J 1‐Cu‐R / k B ≈−800 K, J 2‐Cu‐R / k B ≈−500 K) between the Cu II spins and the coordinating NN spins, whereas [Cu(hfac) 2 (IN 2 Az)] exhibited a ferromagnetic exchange interaction ( J obs‐Cu‐R / k B =+114 K) between the Cu II spin and the imino‐coordinated iminonitroxide spin.