We report on the electrical properties of zeolites, molecular and nanoscale
d guests in porous solids as well as of microporous semiconductors, which h
ave been examined by means of impedance spectroscopy or related methods. Se
lected examples give an insight into charge transport phenomena and show ho
w charge transport and relaxation can be affected by host/guest interaction
s. In this context, potential applications in chemical sensing and catalysi
s are introduced. (C) 2000 Elsevier Science B.V. All rights reserved.