SELF-ASSEMBLED ALKANETHIOLATE MONOLAYERS AS THIN INSULATING FILMS

Simple devices that contain alkanethiolate monolayers sandwiched betwe en conducting films were prepared by fixing a gold film to the surface of an alkanethiolate monolayer (on a gold substrate) with silver pain t. These devices, and similar devices that did not contain alkanethiol ate monolayers, were tested as resistors in d.c. circuits. The devices that contained octadecanethiolate monolayers had resistances of appro ximately 10(12) Ohm, 10 orders of magnitude higher than the resistance of devices that contained no monolayers. Sulfur-terminated alkanethio late monolayers were prepared by treatment of carboxylic acid-terminat ed monolayers with vapours of thionyl chloride followed by vapours of hexane-1,6-dithiol. Attempts to use the sulfur-containing groups at th e surface of this monolayer as 'molecular glue' to attach a flexible g old film to the surface of the monolayer were unsuccessful.