Drexel University

Amar Nath

Som D Tyagi

Nikolai Kopeley

Ferromagnetic porphin compounds may be produced by heating a non-ferromagnetic porphin compound having a central transition metal atom in the non-ferromagnetic porphin molecule and at least some of the pyrrole rings of the non-ferromagnetic porphin molecule having benzene or phenyl groups substituted on or integral with said rings. The non-ferromagnetic porphin compound is heated in the substantial absence of oxygen to a temperature sufficient to pyrolyze at least a portion of the benzene or phenyl groups of the non-ferromagnetic porphin compound. A ferromagnetic porphin compound is formed, which is inherently magnetic and is capable of retaining magnetism when exposed to a magnetic field. The resulting ferromagnetic porphin compounds retain their ferromagnetic properties even up to about 473.degree. K. in air and to much higher temperatures in vacuum or an inert atmosphere.

Method for making ferromagnetic porphin compounds

A method is provided for labeling a complex metal chelate with a radioactive metal isotope via isotopic exchange between the metal atom of the complex metal chelate and the radioactive metal isotope. The complex metal chelate, in a suitable redox state, is mixed in solution with a radioactive metal isotope, freeze-dried, exposed to an electron-accepting gas and thereafter subjected to thermal treatment, whereby isotopic exchange occurs and the complex metal chelate is labeled with the radioactive metal isotope. Furthermore, an additional step comprising exposure to an atmosphere of high relative humidity is provided to increase the yield of isotopic exchange.

Growing community of inventors

Bala Cynwyd, PA, United States of America

Amar Nath