The synthesis and magnetic properties of two novel aromatic N-oxyl radicals based on the quinoline skeleton, 2,2,4-triphenyl-1,2-dihydroquinoline-N-oxyl (1) and 2,2,6-triphenyl-1,2-dihydroquinoline-N-oxyl (2) are described. ESR measurements and DFT calculations for 1 and 2 revealed that their spins were delocalized over the π-systems. Based on the SQUID measurement, 1 exhibited a weak antiferromagnetic interaction in its crystal. For 2, two crystalline phases were obtained, and the α-phase of 2 exhibited a paramagnetic behavior; however, the β-phase of 2 showed a weak ferromagnetic interaction. The observed ferromagnetic interaction was analyzed by a dimer model, and the singlet-triplet gap was estimated to be 2J = +2.5 cm -1.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry
- Materials Chemistry