TEMPERATURE-DEPENDENCE OF THE ELECTRICAL-CONDUCTIVITY OF UREA AND THIOUREA

Correlation of the molecular structure with the thermal study of the e lectricity conductivity of urea and thiourea was carried out. The valu es of the thermal activation energies, as well as the energy gaps corr esponding to the maximum absorption bands of ultraviolet (UV) and visi ble spectra in the solid state indicate that the two compounds behave like semiconductors. The semiconducting properties arise as a result o f electron delocalization via pi-bond formation (C = NH, C = NH2+) and the generation of highly polar resonance hybrid structures.