TY - JOUR
T1 - Azinium-(π-bridge)-pyrrole NLO-phores
T2 - Influence of heterocycle acceptors on chromophoric and self-assembled thin-film properties
AU - Facchetti, Antonio
AU - Abbotto, Alessandro
AU - Beverina, Luca
AU - van der Boom, Milko E.
AU - Dutta, Pulak
AU - Evmenenko, Guennadi
AU - Marks, Tobin J.
AU - Pagani, Giorgo A.
PY - 2002/12/1
Y1 - 2002/12/1
N2 - Novel heterocycle-based azine/azinium-(π-bridge)-pyrrole systems, [(1-(pyrid-4-yl)-2-(N-methylpyrrol-2-yl)]ethene (1), 5-[(N-methylpyrrol-2-yl)azo]quinoline (2), 5-[(N-methylpyrrol-2-yl)azo] isoquinoline (3), and the corresponding N-methotriflates 4-6 were synthesized and characterized. Chromophore precursors 1-3 react with iodobenzyl-functionalized surfaces (10) affording polar-ordered σ-bonded thin films 7-9, respectively. All systems were studied by optical (UV-visible, photoluminescence) spectroscopies, electrochemical (CV), and thermal (TGA, DSC) techniques. Self-assembled chromophore monolayers 7-9 on glass, quartz, and silicon substrates have been characterized by a full complement of physicochemical techniques: optical spectroscopy, aqueous advancing contact angle measurements, specular X-ray reflectivity, atomic force microscopy, and angle-dependent polarized second harmonic generation. Film second harmonic generation responses χ(2)zzz vary more than 1 order of magnitude ranging from 1.3 and 1.6, to 34 × 10-8 esu for 9-, 8-, and 7-based monolayers, respectively. This study demonstrates the following: (i) SA monolayers can be prepared using various types of azine-containing precursors; (ii) chromophore and SA film properties are influenced predominantly by the nature of the π-deficient azinium acceptor; (iii) unsubstituted, π-excessive pyrrol-2-yl rings can act as primary donor groups in push-pull conjugated systems.
AB - Novel heterocycle-based azine/azinium-(π-bridge)-pyrrole systems, [(1-(pyrid-4-yl)-2-(N-methylpyrrol-2-yl)]ethene (1), 5-[(N-methylpyrrol-2-yl)azo]quinoline (2), 5-[(N-methylpyrrol-2-yl)azo] isoquinoline (3), and the corresponding N-methotriflates 4-6 were synthesized and characterized. Chromophore precursors 1-3 react with iodobenzyl-functionalized surfaces (10) affording polar-ordered σ-bonded thin films 7-9, respectively. All systems were studied by optical (UV-visible, photoluminescence) spectroscopies, electrochemical (CV), and thermal (TGA, DSC) techniques. Self-assembled chromophore monolayers 7-9 on glass, quartz, and silicon substrates have been characterized by a full complement of physicochemical techniques: optical spectroscopy, aqueous advancing contact angle measurements, specular X-ray reflectivity, atomic force microscopy, and angle-dependent polarized second harmonic generation. Film second harmonic generation responses χ(2)zzz vary more than 1 order of magnitude ranging from 1.3 and 1.6, to 34 × 10-8 esu for 9-, 8-, and 7-based monolayers, respectively. This study demonstrates the following: (i) SA monolayers can be prepared using various types of azine-containing precursors; (ii) chromophore and SA film properties are influenced predominantly by the nature of the π-deficient azinium acceptor; (iii) unsubstituted, π-excessive pyrrol-2-yl rings can act as primary donor groups in push-pull conjugated systems.
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U2 - 10.1021/cm0205635
DO - 10.1021/cm0205635
M3 - Article
AN - SCOPUS:0036906609
VL - 14
SP - 4996
EP - 5005
JO - Chemistry of Materials
JF - Chemistry of Materials
SN - 0897-4756
IS - 12
ER -