A Weakly Antiferromagnetically Coupled Biradical Combining Verdazyl with Nitronylnitroxide Units

Pavel V. Petunin, Tatyana V. Rybalova, Marina E. Trusova, Mikhail N. Uvarov, Maxim S. Kazantsev, Evgeny A. Mostovich, Lars Postulka, Paul Eibisch, Bernd Wolf, Michael Lang, Pavel S. Postnikov, Martin Baumgarten

Research output: Contribution to journalArticle


An antiferromagnetically (AFM) coupled biradical based on oxoverdazyl and nitronylnitroxide was synthesized in 46 % yield using Sonogashira coupling. The obtained heterobiradical evidenced distinct properties of both radical entities in solution. Depending on the solvent, the prepared biradical crystallized in two different forms. SQUID magnetization measurements on Form II showed coupling constants JintraII/kB=−2.1 K and zJinterII/kB=−11.5 K. Consequently, total intermolecular exchange interactions are five times larger than the intramolecular ones. Further, DFT calculations explained this phenomenon and indicated the advantage of Form I for further in-depth investigations.

Original languageEnglish
Pages (from-to)159-162
Number of pages4
Issue number1
Early online date14 Dec 2019
Publication statusPublished - 1 Jan 2020



  • antiferromagnetism
  • magnetic properties
  • multispin systems
  • radicals
  • Sonogashira coupling

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