MAGNETIC-PROPERTIES OF NITROXIDE RADICALS AS THE SIDE-GROUP OF METHACRYLATE OR METHACRYLAMIDE

The magnetic properties of 4-methacrylamide-, 4-acrylamide-, and sobut yramide-2,2,6,6-tetramethyl-1-piperidinyloxyl (MATMP, AATMP, and SMATM P (saturated MATMP), respectively) were studied. The magnetic suscepti bility, magnetization, and molar heat capacity of MATMP show that the crystal has one-dimensional ferromagnetic coupling just like as the ca se of hacryloyloxy-2,2,6,6-tetramethyl-1-piperidinyloxyl (MOTMP). On t he other hand, both AATMP, where hydrogen atom is substituted for a me thyl group at alpha-position, and SMATMP, where the C=C double bond is saturated, show an antiferromagnetic coupling between nitroxyl radica ls. Magnetic interaction of AATMP was stronger than that of SMATMP. Th e difference of magnetic properties between MATMP and AATMP are simila r to that between MOTMP and -acryloyloxy-2,2,6,6-tetramethyl-1-piperid inyloxyl (AOTMP). The difference in crystal packing between MATMP and AATMP was similar to that between MOTMP and AOTMP. The crystal packing of SMATMP was similar to those of AATMP and AOTMP.