The temperature dependences of the electrical conductivity and Seebeck coefficient for some new carbanion disubstituted ylides are studied. For measurements thin-film samples deposited from solution were used. Dimethylformamide was used as a solvent. It was experimentally established that the respective organic compounds show typical semiconducting characteristics. Some correlations between semiconducting parameters of the compounds (activation energy of electrical conduction, Seebeck coefficient, ratio of carrier mobilities) and their molecular structure are established. It is shown that the model based on the energy band gap representation could be suitable in the study of the electron transfer mechanism through investigated samples. (C) 2003 Elsevier Science B.V. All rights reserved.