TY - JOUR
T1 - Synthesis and magnetic properties of 2,2,4- and 2,2,6-triphenyl-1,2- dihydroquinoline-N-oxyl derivatives
AU - Yao, Masaru
AU - Shibuya, Hideki
AU - Kato, Takashi
AU - Inoue, Hidenari
AU - Yoshioka, Naoki
N1 - Funding Information:
This work was supported in part by a Grant-in-Aid for Scientific Research (B) 15310094, and Exploratory Research 116651070. Financial support from the Keio Gijuku Academic Development Funds is also acknowledged. M.Y. gratefully acknowledges the grant-in-aid for the 21st Century COE program “KEIO Life Conjugate Chemistry” from the Ministry of Education, Culture, Sports, Science, and Technology, Japan.
PY - 2005/11/17
Y1 - 2005/11/17
N2 - 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.
AB - 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.
KW - Aromatic N-oxyl radical
KW - DFT calculation
KW - Magneto-structural correlation
KW - Molecule-based magnetism
KW - Polymorphism
KW - SQUID measurement
UR - http://www.scopus.com/inward/record.url?scp=27644484032&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=27644484032&partnerID=8YFLogxK
U2 - 10.1016/j.poly.2005.03.173
DO - 10.1016/j.poly.2005.03.173
M3 - Article
AN - SCOPUS:27644484032
SN - 0277-5387
VL - 24
SP - 2828
EP - 2834
JO - Polyhedron
JF - Polyhedron
IS - 16-17
ER -