In this report we describe experimental results based on the capillary tunnel junctions of alkyl derivatives such as C16H33OH, C18H37Br, C18H37NH2 and C18H37OH sandwiched between indium electrodes. The tunnel junctions are highly reproducible and stable. The I-V characteristics of the tunnel junction fabricated by this method show rectifying behavior. The results indicate that the electron conductance could be significantly affected by the cooperativity between molecules and electrode materials. (C) 2002 Elsevier Science B.V. All rights reserved.