Organic radicals exhibiting intermolecular ferromagnetic interactions with high probability: 4-arylmethyleneamino-2,2,6,6-tetramethylpiperidin-1-yloxyls and related compounds

被引:70
作者
Togashi, K
Imachi, R
Tomioka, K
Tsuboi, H
Ishida, T
Nogami, T
Takeda, N
Ishikawa, M
机构
[1] UNIV ELECTROCOMMUN, DEPT APPL PHYS & CHEM, CHOFU, TOKYO 182, JAPAN
[2] UNIV TOKYO, INST SOLID STATE PHYS, MINATO KU, TOKYO 106, JAPAN
关键词
D O I
10.1246/bcsj.69.2821
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
A series of 4-arylmethyleneamino-2,2,6,6-tetramethylpiperidin-1-yloxyls (4-arylmethyleneamino-TEMPO) and related compounds were synthesized, and their magnetic susceptibilities were measured by a SQUID magnetometer in the temperature range of 1.8-100 K. Of 165 radicals investigated, 52 kinds of radicals exhibited intermolecular ferromagnetic interactions. These were confirmed by the increase of effective magnetic moments in low-temperature regions. Positive Weiss temperatures (theta), ranging from +0.03 to +0.75 K, were found for these materials. Over 100 kinds of radicals exhibited antiferromagnetic interactions with theta ranging from -0.01 to -24 K. The surprisingly high probability of finding organic radicals with intermolecular ferromagnetic interaction may be understood by the characteristic molecular arrangements in the crystals. An oxygen atom of an NO radical site of a piperidin-1-yloxyl moiety is apt to locate near methyl- and/or methylene-hydrogens of beta-positions of the adjacent molecules, and the resultant spin polarization gives rise to parallel spin alignments of nearest NO sites in the crystals. 4-(4-Iodophenylmethyleneamino)-TEMPO exhibited a bulk ferromagnetic transition at 0.4 K. Six radicals exhibited metamagnetic transitions at magnetic fields lower than 200 Oe below 0.1 K.
引用
收藏
页码:2821 / 2830
页数:10
相关论文
共 70 条
[1]   FERROMAGNETIC INTERMOLECULAR INTERACTION OF THE ORGANIC RADICAL, 2-(4-NITROPHENYL)-4,4,5,5-TETRAMETHYL-4,5-DIHYDRO-1H-IMIDAZOLYL-1-OXY 3-OXIDE [J].
AWAGA, K ;
MARUYAMA, Y .
CHEMICAL PHYSICS LETTERS, 1989, 158 (06) :556-558
[2]   FERROMAGNETIC INTERMOLECULAR INTERACTION IN THE GALVINOXYL RADICAL - COOPERATION OF SPIN POLARIZATION AND CHARGE-TRANSFER INTERACTION [J].
AWAGA, K ;
SUGANO, T ;
KINOSHITA, M .
CHEMICAL PHYSICS LETTERS, 1987, 141 (06) :540-544
[3]   THE ANTI-FERROMAGNETIC STRUCTURE OF TANOL SUBERATE [J].
BENOIT, A ;
FLOUQUET, J ;
GILLON, B ;
SCHWEIZER, J .
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 1983, 31-4 (FEB) :1155-1156
[4]   ANOMALOUS PARAMAGNETISM OF COPPER ACETATE [J].
BLEANEY, B ;
BOWERS, KD .
PROCEEDINGS OF THE ROYAL SOCIETY OF LONDON SERIES A-MATHEMATICAL AND PHYSICAL SCIENCES, 1952, 214 (1119) :451-465
[5]   METAL-NITROXYL INTERACTIONS .14. BIS(HEXAFLUOROACETYLACETONATO)COPPER(II) ADDUCTS OF SPIN-LABELED PYRIDINES [J].
BOYMEL, PM ;
EATON, GR ;
EATON, SS .
INORGANIC CHEMISTRY, 1980, 19 (03) :727-735
[6]   GROUND-STATE PI-ELECTRON TRIPLET MOLECULES OF POTENTIAL USE IN THE SYNTHESIS OF ORGANIC FERROMAGNETS [J].
BRESLOW, R ;
JAUN, B ;
KLUTTZ, RQ ;
XIA, CZ .
TETRAHEDRON, 1982, 38 (06) :863-867
[7]  
BUCHACHENKO AL, 1979, DOKL AKAD NAUK SSSR, V224, P1146
[8]   FERROMAGNETIC ORDER IN THE SULFUR-CONTAINING NITRONYL NITROXIDE RADICAL, 2(4-THIOMETHYL)PHENYL-4,4,5,5-TETRAMETHYLIMIDAZOLINE-1-OXIDE, NIT(SME)PH [J].
CANESCHI, A ;
FERRARO, F ;
GATTESCHI, D ;
LELIRZIN, A ;
NOVAK, MA ;
RENTSCHLER, E ;
SESSOLI, R .
ADVANCED MATERIALS, 1995, 7 (05) :476-478
[9]   A FERROMAGNETIC TRANSITION AT 1.48-K IN AN ORGANIC NITROXIDE [J].
CHIARELLI, R ;
NOVAK, MA ;
RASSAT, A ;
THOLENCE, JL .
NATURE, 1993, 363 (6425) :147-149
[10]   METAMAGNETISM IN TANOL SUBERATE [J].
CHOUTEAU, G ;
VEYRETJEANDEY, C .
JOURNAL DE PHYSIQUE, 1981, 42 (10) :1441-1444