title: A multifunctional high-spin biradical pyrazolylbipyridine-bisnitronylnitroxide.
abstract: [structure: see text] Synthesis and UV-vis, IR, and EPR spectroscopic characterizations, together with X-ray structural analysis, of functional nitronyl- and iminonitroxides attached to pyrazolylbipyridine are described. The exchange interactions between the nitronylnitroxides are found to be stronger than for the iminonitroxides. Although the substitution of a pyridine with the pyrazole ring leads to shorter distances and larger dipolar couplings, the exchange interaction is diminished. While compound 1 forms dimers in the solid state, the terpyridine 3 leads to supramolecular pi-stacking.
authors.affiliation: Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128, Mainz, Germany.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Zoppellaro
authors.forename: Volker
authors.initials: V
authors.lastname: Enkelmann
authors.forename: Ahmed
authors.initials: A
authors.lastname: Geies
authors.forename: Martin
authors.initials: M
authors.lastname: Baumgarten