Nonlinear optical materials chromophores

K.E. Van Cott, T. Amos, H.W. Gibson, R.M. Davis and J.R. Heflin, Characterization of the purity and stability of commercially available dichlorotriazine chromophores used on nonlinear optical materials. Dyes Pigm., 58 (2003) 145-155. 

Chromophore—Polymer Assemblies for Nonlinear Optical Materials... 

For the practical application of second-order NLO materials, not only a high hyperpolarizability but also good thermal stability is required. Heteroaryl diazo chromophores could also act as organic second-order nonlinear optical materials suitable for applications such as second... 

Clearly, a requirement for device quality second-order nonlinear optical materials is a noncentrosymmetric dipolar chromophore lattice. There are several ways by which such lattices have been achieved. With all methods, a force must... 

The area of molecular nonlinear optics has been rejuvenated by efforts to investigate three-dimensional multipolar systems, functionalized polymers as optoelectronic materials, near infrared optical parametric oscillators and related aspects.71 There have been some advances in chromophore design for second-order nonlinear optical materials 72 these include onedimensional CT molecules, octopolar compounds and organometallics. Some of the polydiacetylenes and poly(/>-phenylenevinylene)s appear to possess the required properties for use as third-order nonlinear optical materials for photonic switching.73... 

Nitrobenzothiazole chromophores [588, 589] and their precursors [590] are building blocks of nonlinear optical materials, which are extensively used in the field of optical information processing, optical sensing, data storage, and telecommunications [588, 591], 5-Nitro- [590] and 6-nitro-2-(methyamino)benzothiazole [589] have been prepared from 3-nitro- and 4-nitrophenylthiourea correspondingly, as illustrated in Scheme 2.105. 

NMR spectra of nonlinear optical materials containing nitrobenzothiazole chromophores [785-787], 2-methylamino-5-nitrobenzothiazole [788], 7-alkyl-4-nitrobenzothiazoles [789], 2-chloromethyl-6-nitrobenzothiazole and its sulfonylalky-lation products [790], 2,7-disubstituted 4-nitrobenzothiazole used as antibacterial agents [791], 2-alkyl-5- and 2-alkyl-6-nitrobenzothiazole [792,793], 2-methylmercapto-5-and 2-methylmercapto-6-nitrobenzothiazole [794], l-(P-hydroxyethyl)-6-nitrobenzo-thiazolones-2 [795], 3-methyl- and 4-nitro-6-trifluoromethylbenzothiazolinethiones [796], 2-ethyl-3-methyl-6-nitrobenzothiazolium iodide and tosylate [797], copper(II) complex of N-2-(4-methylphenylsulfamoyl)-6-nitrobenzothiazole [214], and other nitrobenzothiazoles [798-802] have been measured. 

In recent years nonlinear optical materials on the basis of nitroazoles, especially nitrobenzoxazoles and nitrobenzoxadiazoles, have investigated under intense scrutiny, at that and UV and fluorescence spectroscopy is widely used in studying of their structure and dynamics [1202-1225], 4-Aminosubstituted 7-nitrobenzofura-zans have a strong band in the visible region ( =457-483 nm) due to their chromophore properties [777]. 4-Substituted 7-nitrobenzofurazans possess a strong fluorescence that has led to their use as biochemical fluorescent probes in cell membranes [777, 1226-1228],... 

The self-condensing copper-catalyzed polymerization of macromonomer of poly(tBA) with a reactive C—Br bond (H-6) affords hyperbranched or highly branched poly(tBA).447 Copolymerization of H-1 and TV-cyclohexylmaleimide induced alternating and self-condensing vinyl polymerization.448 The residual C—Cl bond was further employed for the copper-catalyzed radical homopolymerization of styrene to give star polymers with hyperbranched structures. Hyperbranched polymers of H-1 further serve as a complex multifunctionalized macroinitiator for the copper-catalyzed polymerization of a functional monomer with polar chromophores to yield possible second-order nonlinear optical materials.325... 

T varies from 235 fs for E — Ep = 0.03 eV to 18 fs for E — Ep > 1.5 eV. It results that, for excitation wavelengths in the near infrared (w 1 oVf the hyperpolarizability can be enhanced up to one order of magnitude under resonant interaction regime. HyperpolarizabiUties of the order of 10 esu are then in principle possible for selected chiral CNT topologies. This value is slightly lower then the estimated hyperpolarizability of chromophores and Sol-Gel, usually accounted as the most efficient second order nonlinear optical materials [29]. 

Polyphosphazenes are suitable materials to be used as carriers for nonlinear optical (NLO) chromophores. Second order NLO properties have been studied for the polymer (128) and blends of (129) with the free chromophore (130) or the cyclophosphazene (131). All systems have glass transition temperatures higher than 135°C and a wide transparency window. The system (129)-(130) appears to exhibit the highest second-harmonic generation (SHG) response. For possible applications the SHG capability has to be enhanced. ... 

Chromophoric self-assembled multilayers. Organic superlattice approaches to thin-film nonlinear optical materials, J. Amer. Chem. Soc. 112 7389 (1990). 

Li, D. Ratner, M.A. Marks, T.J. Zhang, C.Yang, J. Wong. G.K. Chromophoric self-assembled multilayers. Organic superlattice approaches to thin-film nonlinear optical materials. J. Am. Chem. Soc. 1990. 112 (20), 7389. 

Historically, polymeric nonlinear optical materials have ranged from chromophores physically incorporated (i.e., dissolved) in polymer hosts to form composite materials, to chromophores attached by a single covalent bond to a polymer backbone, to chromophores attached at both ends to a polymer network. The physical incorporation of chromophores into polymer hosts to form composites typically... 

Lin, W., Marks, T. J., Yitzchaik, S., Lin, W., and Wong, G. K., New synthetic approaches to self-assembled chromophoric multilayers as second-order nonlinear optical materials. Mater. Res. Soc. Symp. Proc., 392, 95-101 (1995). 

The EFISH method (Singer and Garito, 1981) permitted for the first time the establishment of a correlation between molecular structure of organic chromophores and the first hyperpolarizability p. In this method an electric field is applied to a solution of the nonlinear optical materials, resulting in an alignment of the dipoles. A direct determination of P with the EFISH method is not possible the third-order polarization y is measured, the dipole moment p. must be known, and with these values the hyperpolarizability p can be calculated. The EFISH technique is not readily applied to salts as the solutions conduct electricity. 

M. A. Hnbbard, T. J. Marks, J. Yang, G. K. Wong, Poled polymeric nonlinear optical materials, enhanced second harmonic generation stability of crosslinkable matrix/chromophore essembles. Chem. Mater. 1989,... 

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