New organic non-linear optical materials of stilbene and diphenylacetylene derivatives

Synthesis, crystal growth, characterization and structure–NLO property relationship in 1,3-bis(4-methoxyphenyl)prop-2-en-1-one single crystal

“…The SHG efficiency obtained in the present case is the same as the one reported [30] for this molecule but less than the SHG efficiency reported by Zhao et al [8]. The reason could be due to crystallization from different solvents as seen for other systems [31]. Therefore to enhance the SHG in BMP (i) the crystallization from ethanol solution may be preferred as it shows eight times higher efficiency than the present study and (ii) one should increase the benzoyl arm length of BMP to achieve a lambda structure and such structures are more likely to stack in a head-to-tail fashion and show high SHG [6,13,32].…”

Synthesis and crystal structure of guanidinium L-monohydrogentartrate: encapsulation of an optically nonlinear octupolar cation

“…Over the last ten years organic materials made up of molecules containing polarizable rr-electron systems asymetrized by inter-0108-7681/93/020334-09506.00 acting electron donor and acceptor groups have been extensively developed. Nitroaniline derivatives (Nicoud & Twieg, 1987;Oudar & Hierle, 1977;Zyss, Chemla & Nicoud, 1981;Zyss, Nicoud & Coquillay, 1984), stilbenes (Wang, Tam, Stevenson, Clement & Calabrese, 1988;Tam, Guerin, Calabrese & Stevenson, 1989), cyanobiphenyls (Zyss, Ledoux, Bertault & Toupet, 1991), push-pull polyenes (Barzoukas, Blanchard-Desce, Josse, Lehn & Zyss, 1989) and polyphenyls (Ledoux, Zyss, Jutand & Amatore, 1991) are noteworthy molecules for quadratic nonlinear optical applications. The variety of chemical substitutions provided by organic chemistry guided by empirical as well as more elaborate theoretical models has allowed for the targeted tailoring of optimized crystals towards quadratic nonlinear optics Zyss & Chemla, 1987).…”

In SituDiagnostics of the Crystalline Nature of Single Organic Nanocrystals by Nonlinear Microscopy

“…We show that the polarization analysis of both TPF and SHG from nanocrystals allows the unambiguous discrimination between isolated mono-crystalline and poly-crystalline systems. Moreover, once a nanocrystal has been identified as mono-crystalline, a detailed model for both TPF and SHG polarization responses accounting for the unit-cell symmetry allows the determination of its three-dimensional orientation within the host matrix.The organic nanocrystals that we investigate are based upon the α-((4'-methoxyphenyl)methylene)-4-nitro-benzene-acetonitrile) molecule (CMONS), which exhibits efficient luminescence and quadratic nonlinearity under two-photon excitation [8,9,10]. The bulk crystalline phases of such crystals have three possible polymorphic forms, two being noncentrosymmetric with a very similar unit-cell crystal geometry (forms (a) and (b)) [10,11,12].…”

“…The organic nanocrystals that we investigate are based upon the α-((4'-methoxyphenyl)methylene)-4-nitro-benzene-acetonitrile) molecule (CMONS), which exhibits efficient luminescence and quadratic nonlinearity under two-photon excitation [8,9,10]. The bulk crystalline phases of such crystals have three possible polymorphic forms, two being noncentrosymmetric with a very similar unit-cell crystal geometry (forms (a) and (b)) [10,11,12].…”

“…Consequently, the exploration of polarization responses finally relies on the knowledge of the microscopic α and γ tensor coefficients for TPF detection, and of the β tensor coefficients for SHG. At the molecular scale, we modelled a single CMONS molecule by a rod-like system of susceptibility components denoted α , u defining the CMONS fundamental dipole direction in the molecular frame [8]. The unit-cell tensor coefficients are constructed from the addition of each molecular contribution accounting for their respective orientation in the unit cell, according to the oriented gas model.…”