Adsorption of azothiophene dye having an N-bridging bidentate tail group on gold.
The novel azothiophene derivatives [AT-di(CnSAc) (n=6 and 12)], an azo linkage (N=N) that bridges one phenyl ring with an N-bridging dialkylthioacetate tail and one thiophene ring, are synthesized and characterized. The azothiophene derivatives substituted with electron-withdrawing groups are blue in color, exhibit a bathochromic shift of a longer wavelength, and are electrochemically active. The formation and characterization of AT-di(CnSAc) SAMs with a bidentate tail group of the N-bridging dialkylthioacetate have been studied by surface sensitive techniques such as grazing angle Fourier transform infrared (FT-IR), a quartz crystal microbalance (QCM), spectroscopic ellipsometry, X-ray photoelectron spectroscopy (XPS), and cyclic voltammetry (CV). It has been shown that the adsorption reaction of the thioacetate group is almost spontaneous and the N-bridging dialkylthioacetate SAMs with longer methylene length have a packing density higher than that with a shorter methylene length. However, the sulfur tethers of the N-bridging dialkylthioacetate show incomplete binding of sulfur atoms in AT-di(CnSAc) SAMs.
Bang
Gyeong Sook
GS
National Creative Research Initiative, Center for Smart Molecular Memory, Department of Chemistry, Sungkyunkwan University, 300 Cheoncheon-dong, Jangan-gu, Suwon 440-746, South Korea.
Lee
Junghyun
J
Baek
Hee Yoel
HY
Lee
Hyoyoung
H
Jun
Kun
K
Shin
Seung Rim
SR
D000327:Adsorption; D001665:Binding Sites; D002021:Buffers; D004396:Coloring Agents / Q000737:chemistry*; D004563:Electrochemistry; D006046:Gold / Q000737:chemistry*; D007700:Kinetics; D008958:Models, Molecular; D008968:Molecular Conformation; D010084:Oxidation-Reduction; D017550:Spectroscopy, Fourier Transform Infrared; D013057:Spectrum Analysis; D013438:Sulfhydryl Compounds / Q000737:chemistry; D013455:Sulfur / Q000737:chemistry; D013876:Thiophenes / Q000737:chemistry*; D017155:Wettability
D002021:Buffers; D004396:Coloring Agents; D013438:Sulfhydryl Compounds; D013876:Thiophenes; D013455:Sulfur; D006046:Gold