Upward temperature shift of the intrinsic phase lag of the magnetization of Bis(phthalocyaninato)terbium by ligand oxidation creating an S = 1/2 spin.
An alternating-current (ac) magnetic susceptibility measurement for the [(Pc)(2)Tb(III)](0) complex (Pc = phthalocyaninato) has shown that ligand oxidation of the anionic [(Pc)(2)Tb(III)](-) complex gives rise to a significant upward shift of the temperature range where the magnetization response shows a phase lag behind the time-varying external magnetic field. The peaks of the out-of-phase component of the ac susceptibility of the pi-radical [(Pc)(2)Tb(III)](0) were observed at 50, 43, and 36 K with ac magnetic fields of 10(3), 10(2), and 10 Hz, respectively, which were more than 10 K higher than the corresponding values of the anionic complex with a closed-shell pi-system. The ac susceptibility measurements on the complex with octa(dodecoxy)-substituted Pc ligand, which is readily dilutable in diamagnetic media, proved that the significant rise of the temperatures occurs as an intrinsic single-molecular property of the complex possessing both J = 6 and S = (1)/(2) systems, and is not due to long-range magnetic order or interactions between adjacent unpaired pi-electrons.
Ishikawa
Naoto
N
Departments of Chemistry and Materials Science, Tokyo Institute of Technology, O-okayama, Meguro-ku, Tokyo 152-8551, Japan. ishikawa@chem.titech.ac.jp
Sugita
Miki
M
Tanaka
Naohiro
N
Ishikawa
Tadahiko
T
Koshihara
Shin-ya
SY
Kaizu
Youkoh
Y
D008024:Ligands; D008280:Magnetics; D009942:Organometallic Compounds / Q000737:chemistry*; D010084:Oxidation-Reduction; D013696:Temperature; D013725:Terbium / Q000737:chemistry*
D008024:Ligands; D009942:Organometallic Compounds; D013725:Terbium