Abstract
Regioselective alkylation of 1-(4-pyridyl)-2-[5-(dicyanomethanide)thien-2-yl]ethylene sodium salt (2) by a covalently surface-bound benzylhalide (4) produces a polar-ordered zwitterionic thin film (5). Chemisorption of 2 on the coupling layer 4 was monitored by UV-vis spectroscopy, contact-angle measurements, X-ray photoelectron spectroscopy, and second harmonic generation (SHG). Relative to carbanion 2, the film UV-vis spectrum exhibits a red-shifted (Δλ ∼ 170 nm) charge-transfer band, consistent with quaternization of the pyridyl group of 2 by 4. The nonlinear optical properties of the blue films of 5 were measured by SHG. The average molecular tilt angle of the chromophore was determined to be ∼46°, and χZZZ(2) ∼ 5.0 × 10-8 esu (∼20 pm/V) was estimated at a fundamental wavelength of 1064 nm.
| Original language | English |
|---|---|
| Pages (from-to) | 5939-5942 |
| Number of pages | 4 |
| Journal | Langmuir |
| Volume | 17 |
| Issue number | 19 |
| DOIs | |
| Publication status | Published - Sep 18 2001 |
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ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Colloid and Surface Chemistry
Cite this
Design and preparation of zwitterionic organic thin films : Self-assembled siloxane-based, thiophene-spaced N-benzylpyridinium dicyanomethanides as nonlinear optical materials. / Facchetti, Antonio; van der Boom, Milko; Abbotto, Alessandro; Beverina, Luca; Marks, Tobin J; Pagani, Giorgo A.
In: Langmuir, Vol. 17, No. 19, 18.09.2001, p. 5939-5942.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Design and preparation of zwitterionic organic thin films
T2 - Self-assembled siloxane-based, thiophene-spaced N-benzylpyridinium dicyanomethanides as nonlinear optical materials
AU - Facchetti, Antonio
AU - van der Boom, Milko
AU - Abbotto, Alessandro
AU - Beverina, Luca
AU - Marks, Tobin J
AU - Pagani, Giorgo A.
PY - 2001/9/18
Y1 - 2001/9/18
N2 - Regioselective alkylation of 1-(4-pyridyl)-2-[5-(dicyanomethanide)thien-2-yl]ethylene sodium salt (2) by a covalently surface-bound benzylhalide (4) produces a polar-ordered zwitterionic thin film (5). Chemisorption of 2 on the coupling layer 4 was monitored by UV-vis spectroscopy, contact-angle measurements, X-ray photoelectron spectroscopy, and second harmonic generation (SHG). Relative to carbanion 2, the film UV-vis spectrum exhibits a red-shifted (Δλ ∼ 170 nm) charge-transfer band, consistent with quaternization of the pyridyl group of 2 by 4. The nonlinear optical properties of the blue films of 5 were measured by SHG. The average molecular tilt angle of the chromophore was determined to be ∼46°, and χZZZ(2) ∼ 5.0 × 10-8 esu (∼20 pm/V) was estimated at a fundamental wavelength of 1064 nm.
AB - Regioselective alkylation of 1-(4-pyridyl)-2-[5-(dicyanomethanide)thien-2-yl]ethylene sodium salt (2) by a covalently surface-bound benzylhalide (4) produces a polar-ordered zwitterionic thin film (5). Chemisorption of 2 on the coupling layer 4 was monitored by UV-vis spectroscopy, contact-angle measurements, X-ray photoelectron spectroscopy, and second harmonic generation (SHG). Relative to carbanion 2, the film UV-vis spectrum exhibits a red-shifted (Δλ ∼ 170 nm) charge-transfer band, consistent with quaternization of the pyridyl group of 2 by 4. The nonlinear optical properties of the blue films of 5 were measured by SHG. The average molecular tilt angle of the chromophore was determined to be ∼46°, and χZZZ(2) ∼ 5.0 × 10-8 esu (∼20 pm/V) was estimated at a fundamental wavelength of 1064 nm.
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U2 - 10.1021/la010806s
DO - 10.1021/la010806s
M3 - Article
VL - 17
SP - 5939
EP - 5942
JO - Langmuir
JF - Langmuir
SN - 0743-7463
IS - 19
ER -