Self-assembled monolayers based on chelating aromatic dithiols on gold

Self-assembled monolayers (SAMs) were generated by the adsorption of xylene-alpha(1),alpha(2)-dithiol and 1,2-bis(mercaptomethyl)-4,5-dialkylbenzene derivatives, [CH3(CH2)(m)](2)C6H2[CH2SH](2) (m = 0, 4, 12, 13, 14, 15), on the surface of gold. These monolayers were characterized by optical ellipsometry and contact angle goniometry. Comparison of the thicknesses and wettabilities of the new SAMs to those generated from normal alkanethiols suggests that the new chelating dithiols generate densely packed and highly oriented monolayer films on gold. Furthermore, preliminary studies of film desorption in solution suggest that the new SAMs are more stable than normal SAMs on gold.