Self-assembled monolayers of novel azobenzenes for optically induced switching

Two novel azobenzenethiols containing either a sulfonamide or an amide grou p were synthesised and their ultrathin films were prepared by self-assembli ng (SA) technique. The structure of the SA monolayer (SAM) was characterise d by atomic force microscopy (AFM). The switching between trans- and cis-co nfiguration was observed by measuring the surface potential using the Kelvi n probe technique while alternating irradiating the SAM with ultraviolet an d visible light. A repeated switching of SAMs of 4'-(8-mercapto-octamethyle neoxy)-4-(butyl-amino-sulfonyl) on gold with changes of the surface potenti al by 20 mV was observed. (C) 1999 Elsevier Science S.A, All rights reserve d.