  We report an investigation of electron conduction in oligophenyl based double
barrier molecular device. We have carried out analytical calculations and
numerical simulations on isolated molecules, consisting of aromatic "pi"
conjugated system made up of three phenyl rings separated by insulator groups
-CH_{2}-, -SiH_{2}-, -GeH_{2}- and -SnH_{2}-. We show analytically as well as
numerically that when the two insulator groups are different an asymmetric
electron transport in the presence of external electric field is possible,thus
resembling a diode which allows one way electron transport.
