We have investigated and learned to control switching of oligo(phenylene ethynylene)s embeddedin amide-containing alkanethiol self-assembled monolayers on Au{111}. We demonstrate bias-dependentswitching of the oligo(phenylene ethynylene)s as a function of the interaction between the dipole momentof the oligo(phenylene ethynylene)s and the electric field applied between the scanning tunneling microscopetip and the substrate. We are able to invert the polarity of the switches by altering their designinvertingtheir dipole moments. For appropriately designed switches and matrix molecules, the conductance statesare stabilized by intermolecular hydrogen bonding. These results further support the hypothesis thatconductance switching in these molecules is due to hybridization changes at the molecule−substrate bondsdue to tilting of the switch molecules.