Strategies for Electrooptic Film Fabrication. Influence of Pyrrole−Pyridine-Based Dibranched Chromophore Architecture on Covalent Self-Assembly, Thin-Film Microstructure, and Nonlinear Optical Response

• Published in: Journal of the American Chemical Society Vol. 128; no. 6; pp. 2142 - 2153
• Main Authors: Facchetti, Antonio, Beverina, Luca, van der Boom, Milko E, Dutta, Pulak, Evmenenko, Guennadi, Shukla, Atindra D, Stern, Charlotte E, Pagani, Giorgio A, Marks, Tobin J
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 15-02-2006
• Subjects: CHEMICAL PROPERTIES; Condensed matter: electronic structure, electrical, magnetic, and optical properties; ELECTRO-OPTICAL EFFECTS; Exact sciences and technology; FABRICATION; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; MICROSTRUCTURE; MOLECULAR STRUCTURE; national synchrotron light source; OPTICAL PROPERTIES; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of specific thin films; PHYSICAL PROPERTIES; Physics; Polymers; organic compounds; PYRIDINES; PYRROLES; THIN FILMS; Absorption spectroscopy; Second harmonic generation; Atomic force microscopy; Five membered ring; Nitrogen heterocycle; Electrooptical properties; Push pull compound; Experimental study; Lattice parameters; Photoelectron spectroscopy; Pyrrole derivatives; Monolayers; Nonlinear optics; Organic compounds
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja057556c

The new dibranched, heterocyclic “push−pull” chromophores bis{1-(pyridin-4-yl)-2-[2-(N-methylpyrrol-5-yl)]ethane}methane (1), 1-(pyrid-4-yl)-2-(N-methyl-5-formylpyrrol-2-yl)ethylene (2), {1-(N-methylpyridinium-4-yl)-2-[2-(N-methylpyrrol-5-yl)]ethane}{(1-(pyridin-4-yl)-2-[2-(N-methylpyrrol-5-yl)]ethane}methane (3), N-methyl-2-[1-(N-methylpyrid-4-yl)ethen-2-yl]-5-[pyrid-4-yl]ethen-2-yl]pyrrole iodide (4), bis{1-(N-methyl-4-pyridinio)-2-[2-(N-methylpyrrol-5-yl)]ethane}methane iodide (5), and N-methyl-2,5-[1-(N-methylpyrid-4-yl)ethen-2-yl]pyrrole iodide (6) have been synthesized and characterized. The neutral (1 and 2) and monomethyl salts (3 and 4) undergo chemisorptive reaction with iodobenzyl-functionalized surfaces to afford chromophore monolayers SA-1/SA-2 and SA-3/SA-4, respectively. Molecular structures and other physicochemical properties have been defined by 1H NMR, optical spectroscopy, and XRD. Thin-film characterization by a variety of techniques (optical spectroscopy, specular X-ray reflectivity, atomic force microscopy, X-ray photoelectron spectroscopy, and angle-dependent polarized second harmonic generation) underscore the importance of the chromophore molecular architecture as well as film growth method on film microstructure and optical/electrooptic response.