Open AccessChemical Lithography by Surface‐Induced Photoreaction of Nitro Compounds
Author(s) -
Han Sang Woo,
Lee Inhyung,
Kim Kwan
Publication year - 2004
Publication title -
etri journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.295
H-Index - 46
eISSN - 2233-7326
pISSN - 1225-6463
DOI - 10.4218/etrij.04.0103.0056
Subject(s) - monolayer , lithography , nitro , raman scattering , materials science , amine gas treating , amide , template , photochemistry , self assembled monolayer , nanotechnology , raman spectroscopy , chemistry , chemical engineering , organic chemistry , optoelectronics , optics , alkyl , physics , engineering
Searching for systems of self‐assembled monolayers (SAMs) that can be used as templates for chemical lithography, we found that nitro groups on aromatic SAMs are selectively converted on Ag to amino groups by irradiation with a visible laser. 4‐nitrobenzenethiol on Ag was thus converted to 4‐aminobenzenethiol by irradiating it with an Ar + laser. This was evident from surface‐enhanced Raman scattering (SERS) as well as from a coupling reaction forming amide bonds. The surface‐induced photoreaction allowed us to prepare patterned binary monolayers on Ag that showed different chemical reactivities. Using the binary monolayers as a lithographic template, we induced site‐specific chemical reactions, such as the selective growth of biominerals on either the nitro‐ or amine‐terminated regions by adjusting the crystal‐growth conditions. We also demonstrated that patterned, amine‐terminated monolayers can be fabricated even on gold by using silver nanoparticles as photoreducing catalysts.