Structural evaluation of 6-(10-mercaptodecoxyl) quinoline self-assembled monolayer on gold by reflectance absorption infrared spectroscopy

Self-assembled monolayer (SAM) of 6-(10-mercaptodecaoxyl)quinoline (MDQ) on gold was characterized by reflectance absorption infrared spectroscopy (RA -IR). The molecular orientation of MDQ in the SAM was totally evaluated by comparing the RA-IR spectrum of the SAM with a transmission spectrum of a K Br pellet. It was found that the alkyl chain exhibit a tilting angle of 24 +/- 5 degrees and a twisting angle of 50 +/- 5 degrees. The results suggest ed that the quinoline moieties in the SAM form an order layer upon the hydr ocarbon chain and do not disturb the packing of the alkyl chains obviously. (C) 1999 Elsevier Science S.A. All rights reserved.