STM Imaging of Cyanine Dye J-Aggregates Formed on Carboxyl-Terminated Self-Assembled Monolayers

摘要: We report on the preparation and STM imaging of J-aggregates 1,1‘-diethyl-2,2‘-cyanine (PIC) dye formed a self-assembled monolayer 11-mercaptoundecanoic acid (HS−(CH2)10−COOH). The formation COOH surface was verified by reflection absorption measurements; however, molecular assemblies were not bound strongly enough to SAM withstand lateral forces applied during imaging. found that pretreating with solution 1 mM AgNO3 before application PIC greatly improved stability J-aggregates. suggest reason for this is silver chelate carboxyl head groups which permits subsequent adsorption bromide counterions from solution. counterion has been shown be important in stable images these samples revealed long, essentially linear aggregates (with packing structure similar pr...