ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

The measurement of electrical resistivities as a function of temperature for fluorene, caffeine, and their presumed complexes

J. Vanžura and Ľ. Krasnec

The Rssearch Institute of the Pharmaceutical Faculty, Komenský University, Bratislava

Abstract: By voltampsric method a polarizing current and conductivity and their temperature depend зпсе with the pressed samples of caffeine and fluorene and their mixtures (1:9) has been measured. It has been observed that the polarizing currents, which are very similar with the compounds examined and their mixtures, respectively dissapear in about 10 minutes but these current of the mixture prepared termally at 120 °C has the course substantially different and exhibits a constant value. A calculated activation energy of caffeine and fluorene has been found to be 1.2 ± 0.1 eV and 4.2 eV, respectively. This value differs from that obtained by measuring of the temperature dependence of the resistances of crystalline fluorene. We have found that specific resistances of the samples examined are by three-times order higher that one is of the mixture termally prepared, which might be ascribed to the slight interaction between caffeine and fluorene, respectively.

Full paper in Portable Document Format: 222a124.pdf (in Czech)

Chemical Papers 22 (2) 124–129 (1968)