Supramolecular nonlinear optical properties

From Molecular to Supramolecular Nonlinear Optical Properties... 

The study of chiral materials with nonlinear optical properties might lead to new insights to design completely new materials for applications in the field of nonlinear optics and photonics. For example, we showed that chiral supramolecular organization can significantly enhance the second-order nonlinear optical response of materials and that magnetic contributions to the nonlinearity can further optimize the second-order nonlinearity. Again, a clear relationship between molecular structure, chirality, and nonlinearity is needed to fully exploit the properties of chiral materials in nonlinear optics. 

Nonlinear optical (NLO) properties are usually considered to depend on the intrinsic features of the molecule and on the arrangement of a material. An intermediate level of complexity should also be taken into account, that of the formation of well-defined supermolecules, resulting from the association of two or more complementary components held together by a specific array of intermolecular interactions (1). Such intermolecular bonding may yield more or less pronounced NLO effects in a variety of supramolecular species (2). Thus, three levels of nonlinear optical properties may be distinguished the molecule, the supermolecule and the material. The molecular and supramolecular levels involve respectively - intramolecular effects and structures, -... 

T. Verbiest, S. Van Elshocht, M. Kauranen, L. Hellemans, J. Snauwaert, C. Nuckolls, T. J. Katz, A. Persoons, Strong Enhancement of Nonlinear Optical Properties Through Supramolecular Chirality, Science 1998, 282, 913-915. 

Le Bouder, T., Maury, O., Bondon, O., Costuas, K., Amouyal, E., Ledoux, I., Zyss, J., Le Bozec, H. Synthesis, photophysical and nonlinear optical properties of macromolecular architectures featuring octupolar tris(bipyridine) ruthenium(II) moieties evidence for a supramolecular sell-ordering in a dentritic structure. J. Am. Chem. Soc. 125, 12284-12299 (2003)... 

Hoss. R. Konig, O. Kramer-Hoss. V. Berger. U. Rogin. P. Hulliger. J. Crystallization of supramolecular materials Perhydrotriphenylene (PHTP) inclusion compounds with nonlinear optical properties. Angew. Chem. Int. Ed. Engl. 1996. 35. 1664-1666. 

Verbiest. T. van Elshocht. S. Karuanen. M. Heliemans. L. Snauwaert, J. Nuckolls. C. Katz, T.J. Persoons. A. Strong enhancement of nonlinear optical properties through supramolecular chirality. Science 1998, 282, 913. 

Lin W, Evans OR, Xiong RG, Wang Z (1998) Supramolecular engineering of chiral and acentric 2D networks. Synthesis, structures, and second-order nonlinear optical properties of bis(nicotinato)zinc and bis 3-[2-(4-pyridyl)ethenyl]benzoato cadmium. J Am Chem Soc 120 13272-13273... 

Romogaeva, A., Gu, F.L., Imamura, A., Aoki, Y. Electronic structures and nonlinear optical properties of supramolecular associations of benzo-2,13-chalcogendiazoles by the elongation method. Theor. Chem. Acc. 125,453-460 (2010)... 

The chemistry of metal complexes featuring alkyne and alkynyl (acetylide) ligands has been an area of immense interest for decades. Even the simplest examples of these, the mononuclear metal acetylide complexes L MC=CR, are now so numerous and the extent of their reaction chemistry is so diverse as to defy efforts at a comprehensive review. " The utility of these complexes is well documented. Some metal alkynyl complexes have been used as intermediates in preparative organic chemistry and together with derived polymeric materials, many have useful physical properties including liquid crystallinity and nonlinear optical behaviour. The structural properties of the M—C=C moiety have been used in the construction of remarkable supramolecular architectures based upon squares, boxes, and other geometries. ... 

Nagamura describes in Chapter 9 the fabrication and properties of supramolecular and polymeric systems that display unique linear and nonlinear optical response. Such materials may find application in high-density information processing systems of the future. Chapter 10, by Shinkai and James, describes the properties of supramolecular photoswitchable ion receptors. Finally, in Chapter 11, Ishikawa and Ye discuss the application of state-of-the art fluorescence methods to explore the properties of polymers with nm-scale resolution. 

The supramolecular structure of block co-polymers allows the design of useful materials properties such as polarity leading to potential applications as second-order nonlinear optical materials, as well as piezo-, pyro-, and ferroelectricity. It is possible to prepare polar superlattices by mixing (blending) a 1 1 ratio of a polystyrene)-6-poly(butadiene)-6-poly-(tert-butyl methacrylate) triblock copolymer (SBT) and a poly (styrene)-Apoly (tert-butyl methacrylate) diblock copolymer (st). The result is a polar, lamellar material with a domain spacing of about 60 nm, Figure 14.10. 

A continuous research work on membrane properties and fundamental aspects of transport phenomena in the various membrane operations is important for the fumre of membrane science and technology. There is a need for both basic and applied research to develop new membranes with improved properties and new membrane processes. These research efforts must take into account the studies done in other areas such as supramolecular chemistry, molecular imprints materials, nanotechnology, nonlinear optics, studies on biological membranes and biological phenomena, etc. 

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