SELF-ASSEMBLED ALKANETHIOLATE MONOLAYERS AS THIN INSULATING FILMS

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