Optical properties, of polydiacetylene

This paper will review the linear and nonlinear optical properties of polydiacetylenes with an emphasis on our work with the nBCMU polymers. The following section will discuss material... 

Volkov, V.V., Asahi, T., Masuhara, H., Masuhara, A., Kasai, H., Oikawa, H. and Nakanishi, H. (2004) Size-dependent optical properties of polydiacetylene nanocrystal. J. Phys. Chem. B, 108, 7674-7680. 

Microcrystals of some diacetylenes, prepared by the reprecipitation method, have been studied as dispersions in liquid media. Interesting behavior has been observed in the solid-state polymerization of diacetylene monomers and with the optical properties of polydiacetylene (PDA) microcrystals. First, the polymerization perfectly proceeded from one end to the other end of the diacetylene microcrystals. Next, the excitonic absorption peak position was found to shift to higher energy side with decreasing size of the PDA microcrystals. The size effect was observed even for crystals as large as 100 nm or more in contrast to conventional quantum effect of inorganic semiconductors where size effect is observed only for microciystals of less than about 10 nm size. In addition, since the microcrystal dispersions in water have low optical loss, the c tical Kerr shutter response of PDA microciystals could be measured, and the non-resonant value was estimated to be on the order of 10 to 10" esu in very low concentrations (ca. 10 M). 

The nonlinear optical properties of polydiacetylenes are subject of an increasing interest in last years (1-4). This is due to the fact that polydiacetylenes are a one-dimensionnal system of higly polarizable conjugated tt elections The polarization depends strongly on electron delocalization length Moreover, the electronic origin of hyperpolarizability implies short response times On the other hand, the wave dispersed measurements of molecular hyperpolarizabilities yield information about forbidden electronic transitions In fact the bulk polarization can be developped in external electric field power series ... 

A number of studiesof the nonlinear optical properties of polydiacetylene multilayers have been undertaken. It is obvious from these investigations that there is a strong possibility.that these materials have applications in integrated optics as wave guide materials. However this will be dependent on the ability to control morphology and structure in these layers, thus indicating the... 

Nakanishi, H., Matsuda, H., Okada, S., and Kato, M., Nonlinear optical properties of polydiacetylenes with JC-conjugation between the main chain and the substituents, in Nonlinear Optics of Organics and Semiconductors Springer Proc. Phys., 36), Kobayashi, T, Ed., Springer-Verlag, Berlin, 1989, 469. 

Okada, S., Ohsugi, M., Masaki, A., Matsuda, H., Takaragi, S., and Nakanishi, H., Preparation and nonlinear optical property of polydiacetylenes from unsymmetrical diphenylbutadiynes with trifluoromethyl substituents, Mol. Cryst. Liq. Cryst., 183, 81, 1990. 

CHARRA F. and NUNZI J.M., (1989b), "Strong Field Nonlinear Optical Properties of Polydiacetylenes" in Nonlinear Optical Materials II, J.B. Grun ed., Proc. SPIE, Vol. 1127, 173-181. 

Ohnishi, S., Orimoto, Y, Gu, F.L., Aoki, Y Nonlinear optical properties of polydiacetylene with donor-acceptor substitution block. J. Chem. Rhys. 127, 084702 (2007)... 

The nonlinear optical properties of novel, soluble polydiacetylenes are reviewed and discussed. 

For the elucidation of the optical and nonlinear optical properties of the polydiacetylene layers, we have employed a wave-... 

Linear and nonlinear optical properties of a class of polydiacetylenes that can be grown as large area and controlled thickness thin films have been investigated. This involved an integrated research effort including monomer synthesis, thin film growth and new measurement techniques. 

The complex morphology of most conjugated polymers prevents direct measurement, and hinders understanding, of their intrinsic properties. Such problems do not occur for the polydiacetylenes, which can be prepared as macroscopic single crystals. Since polydiacetylenes can also be obtained in less perfect forms the effects of disorder can be studied. Spectroscopic techniques have been widely used to study the intrinsic properties of polydiacetylenes and their modification by disorder. The results obtained by optical and electron spin resonance spectroscopy are discussed. 

Conjugated polymers satisfy these requirements and have thus emerged as the most widely studied materials for their susceptability. Some of the examples of conjugated polymers, that have been studied for their third order NLO properties, are polydiacetylenes, poly-p-phenylenevinylenes and polythiophenes. However, CVD has only been used in the case of poly-p-phenylenevinylenes (PPV) [section 3.4], although values have not been reported. An excellent review of third order nonlinear optical properties of PPV in general, can be found in literature. Recently, McElvain et al. ° reported the values of CVD polyazomethines to be... 

Many aspects of the preparation and properties of polydiacetylenes are the subject of lively debate. This review presents recent results that bear on some of these controversies. First the relationship of diacetylene monomer crystal structure and solid-state reactivity is discussed. Secondly the temporal evolution of solvato-chromio transitions of soluble polydiacetylenes is displayed. Optical and Raman spectra reveal the occurrence of an intermediate form of the polymer. A model compatible with these results is described. 

Camacho, M.A., Kar, A.K., Lindsell, W.E.. Murray, C., Preston, P.N., Wherrett, B.S. Synthesis and nonlinear optical properties of functionalized polydiacetylenes and their complexes with transition metals. J. Mater. Chem. 9, 1251-1256 (1999)... 

We believe that our foregoing discussion about the thermal and optical properties of the 1,4-diphenylbutenynes and 1,4-dipheny1-1,3-butadienes can be extended to polydiacetylene systems. These polymers, with their extended tt - system should undergo a facile thermal or photochemical cis-trans isomerisation even at room temperature and daylight, cis"-trans isomerisation requires a 180 rotation around a double bond. Certainly this is not possible in the rigid crystalline state or in the aggregate form of the polymer at room temperature,... 

In this chapter, a detailed description is given of these intriguing optical properties of certain polythiophene derivatives, and their analogy with chromic effects found in other 7r-conjugated (polydiacetylenes) and or-conju-gated polymers (polysilanes) is discussed. In order to explain these transitions, various molecular mechanisms are described. Finally, potential applications of these interesting optical effects are presented. 

The synthesis of polydiacetylenes with bipyridine metal complexes in their sidechains has been achieved by Lindsell and cowoikers (Scheme 17). Complexes of nickel, copper, ruthenimn, and molybdenum were synthesized and the nonlinear optical properties of the resulting polymers examined. 

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