Electrical transport as a function of temperature in urea and cobalt (III)-urea complex

The temperature dependence of the electrical conductivity, and the voltage- current dependence of urea and its cobalt solid complex were determined. Th e values of the thermal activation energies indicate that the two compounds behave like semiconductors. The semiconducting properties of the ligand 'u rea' are due to the electron delocalization via pi-bond formation (C=NH, C= (+)(2)) as well as the lone pair of electrons on the oxygen atoms of urea m olecules. The high conductivity values of urea compared with those of its c obalt solid complex was suggested to be due to the ease of releasing the lo ne pair electrons on the oxygen atom as well as the hydrogen transfer durin g enol formation of urea molecules. The infrared, ultraviolet and visible a bsorption measurements were carried out to rationalize the mechanism of the conduction process in the investigated compounds.