Grafting of monocarboxylic substituted polychlorotriphenylmethyl radicals onto a COOH-functionalized self-assembled monolayer through copper (II) metal ions.
Langmuir
; 24(13): 6640-8, 2008 Jun 01.
Article
em En
| MEDLINE
| ID: mdl-18522443
ABSTRACT
A monocarboxylic substituted polychlorotriphenylmethyl radical (PTMCOOH) has been grafted onto a COOH-functionalized SAM (mercaptohexadecanoic acid, MHDA SAM), using copper (II) metal ions as linkers between the carboxyl groups of the SAM and the ligand. The metal-radical adlayer has been characterized thoroughly using different surface analysis techniques, such as contact angle, IRRAS, XPS, SPR, ToF-SIMS, SFM, and NEXAFS. The magnetic character was confirmed by EPR. The density of unoccupied states was investigated using X-ray absorption spectroscopy. A low-energy peak in the NEXAFS spectrum directly revealed the presence of partially occupied electronic levels, thus proving the open-shell character of the grafted ligands. SEM measurements on a laterally patterned sample prepared by muCP of MHDA in a matrix of hexadecane thiolate (a CH 3-terminated SAM) was performed to demonstrate that the metal-assisted anchoring of the open-shell ligand occurs selectively on the COOH terminated SAM. These results represent an easy and new approach to anchor organic radicals on surfaces and constitute a first step toward the growth of magnetic metal-organic radical-based frameworks on solid substrates.
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MEDLINE
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En
Ano de publicação:
2008
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Article