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| Untersuchte Arbeit: Seite: 42, Zeilen: 9-22 |
Quelle: Lee et al 2004 Seite(n): 1813, 1814-1815, Zeilen: 1813: left col. 16-24; 1814: right col. 62-68 - 1815: left col. 1-4 |
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| In new photolithographic techniques a photo-acid generator (PAG) is used for direct photochemical modification and patterning of thin organic films as well as self-assembled mono-layers (SAMs) [Ulm96]. This specific technology employs PAG, a chemical species that releases a proton upon photolysis, to hydrolyze terminal hydrophobic tert-butyl ester groups to a reactive hydrophilic carboxylic acid group. When exposed to UV light, the PAG produces a proton that catalyzes the deprotection of the tert-butyl ester (compound 1) to form a carboxylic acid (compound 2) and butylene gas. Photodeprotection of the hydrophobic tert-butyl ester to form a carboxylic acid offers a photochemical alternative to more traditional chemical deprotection methods, such as hydrolysis with trifluoroacetic acid [Lee04], also shown in Scheme 2-9. Both of these deprotection schemes occur readily in solution to produce an acid-terminated azobenzene alkanethiol compound but can also be applied on SAMs on gold of the discussed molecules.
[Lee04] Lee, K.; Pan, F.; Carroll, G. T.; Turro, N. J.; Koberstein, J. T. Langmuir 2004, 20, 1812. [Ulm96] Ulman, A. Chem. Rev. 1996, 96, 1533. |
[page 1813]
In this report, we describe a new photolithographic technique for direct photochemical modification and patterning of surface properties of self-assembled monolayers (SAMs).22 The specific technology employs a photoacid generator (PAG), a chemical species that releases a proton upon photolysis, to hydrolyze terminal tert-butyl ester groups located at the surface of a SAM to reactive carboxylic acid groups in a process that is almost devoid of reagents and safety hazards.23,24 [page 1814] When exposed to UV light, the PAG produces a proton that catalyzes the deprotection of the tert-butyl ester (compound 1, SAM 1) to form a carboxylic acid (compound 2, SAM 2) and butylene gas. Photodeprotection of the hydrophobic tert-butyl ester to form a carboxylic acid offers a photochemical alternative to more traditional chemical deprotection [page 1815] methods, such as hydrolysis with trifluoroacetic acid,42 also described in Figure 1. Both of these deprotection schemes occur readily in solution to produce an acid-terminated azobenzene alkanethiol compound. (22) Ulman, A. Chem. Rev. 1996, 96, 1533. (23) Wallraff, G. M.; Hinsberg, W. D. Chem. Rev. 1999, 99, 1801. (24) Kim, J.; Kang, J.; Han, D.; Lee, C.; Ahn, K. Chem. Mater. 1998, 10, 2332. |
Nothing has been marked as a citation. Bsi's Scheme 2-9 on the page following is identical to Figure 1 from Lee et al., 2004. |
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