Nonlinear optical properties, solid state

Polydiacetylenes are obtained as single crystals by topochemical solid-state polymerization of the monomer single crystal. These compounds have received considerable attention because of their one-dimensionally -conjugated structure. Their unique --electron structures, and therefore superior third-order nonlinear optical properties, have been extensively investigated. 

Xue D., Betzler K., Hesse H. and hammers D., Nonlinear optical properties of borate crystals. Solid State Commm., 114 (2000) pp. 21-25. 

CALCULATIONS OF NONLINEAR OPTICAL PROPERTIES FOR THE SOLID STATE... 

Our discussion has so far been concerned with the microscopic response of a molecule to an external electric field, and thus with an expansion of the molecular energy in orders of the response with respect to the external field, giving rise to the molecular (hyper)polarizabilities. Although experimental data for nonlinear optical properties of molecules in the gas phase do exist [55], the majority of experimental measurements are done in the liquid or solid states, as these states also are the ones that are of greatest interest with respect to developing materials with specifically tailored (non)linear optical properties. 

It is also important to realize that the nonlinear optical properties of a molecule in solution or in the solid state will differ from that of the isolated molecule due to polarization effects caused by the surrounding molecules. In theoretical calculations of molecules in die liquid phase, these effects may be modeled using for instance dielectric continuum models [33, 41, 42, 52, 56]. The use of such schemes for estimating the polarization of the solute by the solvent does not resolve the issue of local field factors. 

G477> this compound crystallizes in a noncentrosymmetric group (a chiral helix) and owing to its high dipole moment shows nonlinear optical properties in the solid state. The structures of other N7/-pyrazoles bearing a 4-nitro substituent were determined and compared with those of the corresponding 4-unsubstituted-pyrazoles (pyrazole itself (7), 3,5-dimethyl (19), 3,5-diphenyl (17),... 

This reaction, called a four-center photopolymerization, is a typical example of topochemical reactions used to prepare polymer crystals.5 The changes in higher-order structure during the reaction are shown in Table 2.5 . Various polydiacetylene crystals have also been prepared by solid-state photopolymerization of diacetylene monomer crystals, such as 1,6-dicarbazoyl-2,4-hexadiene. These syntheses have attracted considerable interest, since they can lead to organic materials of high conductivity or of nonlinear optical properties. 

Reviews G. R. Meridith, MRS Bulletin. 13(8) 24-29, (1988) A. J. Heeger and D. R. Ulrich, "Nonlinear Optical Properties of Polymers", North-Holland Press, New York, (1988) P. N. Prasad and D. A. Ulrich, "Nonlinear Optical and Electroactive Polymers", Plenum, New York, (1988) D. J. Sandman, "Solid-State Polymerization", American Chemical Society, Washington, DC, (1987) D. J. Williams, "Nonlinear Optical Properties of Organic and Polymeric Materials", American Chemical Society, Washington, DC, (1983). 

Transition metal oxides constitute an interesting and widely investigated class of compounds in solid state and materials chemistry. They form the basis of solid state chemistry for the study of structure, composition and various physical and chemical properties that are not only of fundamental importance, but have technological applications. The important properties of these materials include superconductivity, ferromagnetism, magnetoresistance, half-metallicity, catalysis, nonlinear optical property, ferroelectri-city and multiferroic property all are of current immense interest. 

Most theoretical discussions for molecules concentrate on calculations of second-order nonlinear optical properties. These results can be used equally well for the design of either molecules or molecular fragments. The latter are intended for inclusion in polymers as either a solid solution or side-chains. These are discussed in detail in section 4.3, together with systems in which a crystalline phase is dispersed in a polymer matrix. In molecularly dispersed systems the incorporation and orientation of an active species in a polymer obviates the need for a non-centrosymmetric crystal structure but does require the imposition of a polar state on the polymer (e.g. with an applied electric field). Thus molecular species that as crystals are not useful as second-order nlo materials (because they adopt a centrosymmetric structure) may be applicable in a polymeric system. Though it has received less attention in the past, considerable effort has recently been devoted to theoretical studies of... 

Champagne, B. and Bishop, D.M. (2003) Calculations of nonlinear optical properties for the solid state. Adv. Chem. Phys., 126, 41-92. 

Molli, M., Parola, S., Chunduri, L.A. A. et al. (2012) Solvothermal synthesis and study of nonlinear optical properties of nanocrystalline doped bismuth telluride. Journal of Solid State Chemistry, 189, 85-89. 

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