ELECTRICAL-PROPERTIES AND SPECTRAL STUDIES OF SOME SCHIFF-BASE COMPLEXES

Electrical properties viz. conductivities, energy gaps and Seebeck coefficient have been determined for various schiff base complexes. The complexes of N-(2-hydroxy)-benzylidine-beta-alanine with Cu2+, Zn2+, Hg2+, Pb2+, Rb2+, and UO22+ have been used as model compounds and they have been characterized on the basis of elemental analysis, IR and NMR spectral data. The Seebeck coefficient of all these complexes are positive and the correlation with conductivity data indicates the concentration of the carriers of several orders, the mobility ratio increasing with the increase in temperature. On the basis of optical analysis the energy gap value is 4.8 +/- 0.1 eV which is in good agreement with that calculated from the conductivity data at higher temperature (4.6 +/- 0.2 eV). At low temperature, the energy gaps have the value 0.188 +/- 0.016 eV, which is similar to that of normal semiconductors. The values of the mobility of holes are mu(h) = 6.55 +/- 1.33 Ue and mu(h) = 3.57 +/- 0.43 Ue at low and high temperature respectively. It has been established that the schiff base is an electronic conductor. The conductivity measurements are apparently an additive function of the intrinsic conductance with an exponential temperature dependence.